Abstract:
A computerized method for normalizing the results of clinical laboratory tests to a reference scale includes providing a measured value of a clinically significant parameter, providing a set of patient data, and providing a set of method data, including an indication of a method used by a testing instrument used to measure the measured value. One or more correlation factors are retrieved including a method correlation factor from a computer readable database based on the method data. The method correlation factor corresponds to the method used by the testing instrument used to measure the measured value. A normalized value of the clinically significant parameter is calculated based upon the one or more correlation factors. The normalized value may correspond to a value on the reference scale regardless of the method used by the testing instrument.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a non-provisional application claiming priority to U.S. Application Ser. No. 61/255,979 filed on Oct. 29, 2009, titled METHOD FOR NORMALIZING CLINICAL LABORATORY MEASUREMENTS which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a method of normalizing clinical laboratory measurements. In particular, the present invention relates to a method of normalizing clinical laboratory measurements across a range of measurement devices and methods. 
     Medical practitioners including physicians utilize clinical laboratory measurements in making treatment decisions and diagnostic determinations for patients. These measurements are generally made using a variety of techniques that may directly measure the amount of a target compound in blood or urine, or they may indirectly measure the amount of a target compound by using a reagent to produce a secondary compound that can be measured more easily and/or accurately than the target compound. The target compounds may be electrolytes, enzymes, antibodies, or other compounds of clinical interest. 
     Currently, clinical laboratory measurements are compared to a reference range. The reference range provides a range of values for a particular measurement that is considered normal and is defined by a maximum value and a minimum value. The reference range for a particular measurement may vary from one clinical laboratory to another depending on the testing equipment used, the lot number of any reagents used, and the date on which the measurement is taken. Each time a new reagent lot number is used, a new reference range must be determined for the method and testing instrument being used by employing reference samples for calibration. 
     As a result, the measured value of a target compound provided by a particular testing method is not useful as an absolute measurement, but only as the measured value compares to a specific reference range that will vary depending on the lot number of reagent used. In addition, the reference range for “normal” valued may vary for patients of different demographic groups. For example, a physician may recommend medical intervention for a patient who is 60 years old with a particular measured cholesterol level and forgo medical intervention for a 20 year old patient with the same measured cholesterol level. This shows that the reference ranges for some measured values are only useful for particular age groups. 
     The fact that the measured values and reference ranges may vary from laboratory to laboratory and from patient to patient results in a complicated evaluation for physicians and other medical practitioners when it comes to evaluating medical decision points. Such complexity not only consumes resources, but makes the sharing of information between facilities difficult and increases the chance of medical errors. 
     Accordingly, there is a need for a method of normalizing clinical laboratory measurements that simplifies the process of comparing a level of a target compound to a reference range. 
     SUMMARY OF THE INVENTION 
     A computerized method for normalizing the results of clinical laboratory tests to a reference scale includes providing a measured value of a clinically significant parameter, providing a set of patient data, and providing a set of method data, including an indication of a method used by a testing instrument used to measure the measured value. One or more correlation factors are retrieved including a method correlation factor from a computer readable database based on the method data. The method correlation factor corresponds to the method used by the testing instrument used to measure the measured value. A normalized value of the clinically significant parameter is calculated based upon the one or more correlation factors. The normalized value may correspond to a value on the reference scale where the scale includes maximum and minimum allowable limits for the normalized value regardless of the method used by the testing instrument. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a flow diagram for the process of ordering and carrying out a clinical laboratory test within an electronic health record management system. 
         FIGS. 2   a - 2   d  are flow diagrams for the process of  FIG. 1  including automatic normalization of a measured value. 
         FIG. 3  is a chart showing a linear regression for correlating two separate methods for measuring blood urea nitrogen. 
         FIG. 4  is a chart showing a linear regression for correlating two separate methods for measuring albumin. 
         FIG. 5  is a chart showing a linear regression for correlating two separate methods for measuring high density lipoprotein. 
         FIG. 6  is a chart showing a linear regression for correlating two separate methods for measuring complement 4. 
         FIG. 7  is a chart showing a linear regression for correlating two separate methods for measuring haptoglobin. 
         FIG. 8  is a chart showing a linear regression for correlating two separate methods for measuring potassium. 
         FIG. 9  is a chart showing a linear regression for correlating two separate methods for measuring low density lipoprotein. 
         FIG. 10  is a chart showing a linear regression for correlating two separate methods for measuring blood lipid level. 
         FIG. 11  is a chart showing a linear regression for correlating two separate methods for measuring magnesium. 
         FIG. 12  is a chart showing a linear regression for correlating two separate methods for measuring sodium. 
         FIG. 13  is a chart showing a linear regression for correlating two separate methods for measuring pre-albumin. 
         FIG. 14  is a chart showing a linear regression for correlating two separate methods for measuring phosphorus. 
         FIG. 15  is a chart showing a linear regression for correlating two separate methods for measuring bilirubin. 
         FIG. 16  is a chart showing a linear regression for correlating two separate methods for measuring triglyceride level. 
         FIG. 17  is a chart showing a linear regression for correlating two separate methods for measuring total protein. 
         FIG. 18  is a chart showing a linear regression for correlating two separate methods for measuring transferrin. 
         FIG. 19  is a chart showing a linear regression for correlating two separate methods for measuring uric acid. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present method allows for changes to clinical laboratory methods and equipment while allowing a physician or other medical practitioner to use the same medical decision points when evaluating the results of clinical laboratory tests. In order to allow medical practitioners who use different laboratories with different equipment to evaluate a clinical laboratory measurements against a single reference range. 
     Variations in laboratory measurements are more extreme for certain types of tests than others. For example, measurements of electrolytes using different clinical methods will not be as disparate as measurements of enzyme or antibody levels done by different methods. 
     In particular, linear regression methods can be used to normalize measured values. In these methods, a single method of measuring a clinically important value may be selected as a “gold standard” (i.e. the standard method) against which other methods may be normalized. Once normalized, measured values may be compared to the reference range for the “gold standard” method for purposes of making medical decisions. In some methods, a measured value Xm may be normalized according to a linear equation to provide a normalized value XF according to the equation where M mfg  is a correlation factor that equals the slope of the regression line used to correlate the measured value X m  to a value provided by the standard method and I mfg  is the vertical intercept of the line.
 
 X   m   *M   mfg   +I   mfg   =X   F  
 
     In most cases, the regression line will have an intercept of zero, in which case the intercept may be ignored. 
     While a particular method or equipment for measurement may be selected for the standard method, the normalized value may also be correlated for reagent lot number, patient age, date range during which the testing was completed, or other factors. In these methods, the normalized value X F  may be determined by the following formula:
 
( X   m   *M   mfg   +I   mfg )( A   m   +I   A )( D   m   +I   D )( L   M   +I   L )= X   F  
 
where A m  is an age correlation factor (i.e. the slope of the regression line for correlating the age of a patient to a standard age and I A  is the slope of that line; D m  is a date range correlation factor (i.e. the slope of the regression line for correlating the date range during which the testing was done to a standard date and I D  is the intercept of that line; and L M  is a lot number correlation factor (i.e. the slope of the regression line for correlating the lot number of a reagent used in a particular method to a standard lot number and I L  is the intercept of that line. Again, the intercepts of the various lines should approximate zero, so the formula simplifies to:
 
 X   m   *M   mfg   *A   m   *D   m   *L   M   =X   F  
 
     The correlation factors above would need to be determined by regression analysis done for each specific method being done. In other words, the age correlation for one method may be different than for another. Accordingly, a computer accessible library would be useful for storing and accessing the correlation factors for a variety of methods so that they may be used to calculate the normalized value. In some embodiments of the invention, chemical reagent manufacturers could provide reagent lot number correlation factors to a centralized system that could then make those correlation factors available to clinical laboratories on a subscription basis. Providing access to these correlation factors would lessen the need for, or compliment, internal validations done by clinical laboratories when they begin to use a new lot number of a reagent. 
     The correlation factors may be calculated by using one of a variety of linear regression models. A standard regression may be carried out, however, such a model does not account for random error that may be present in the data. Such errors, may be transcription errors, equipment errors, or errors attributable to a technician. Such errors can be accounted for by using a Deming regression model which is the preferred regression model for use with the methods described, especially when the data being normalized is produced by methods that are similar to the standard method. 
     In a preferred embodiment, a clinical test utilizing a particular method, employing a particular lot number of reagent, within a particular date range, and for a patient of a particular age would be used to measure a value. This measured value would automatically be normalized against a standard method based on test method, date range, lot number, and age correlation factors. The normalized value could then be used with the reference range for the standard method to make medical decisions. All of the information about the test method, reagent lot number, date range, and patient age could be maintained in an electronic health record and/or a laboratory information system so that the normalization process could be completely automated. 
     Referring to  FIG. 1  a system for ordering and carrying out a clinical laboratory test within an electronic health record management system is provided. Orders for a laboratory test are entered into the system and transmitted to a Health Information System (HIS). The HIS relays the orders to a Laboratory Information System (LIS) which is coupled to an instrument. A laboratory technician utilizes the instrument to perform the ordered test on a specimen. The Instrument then relays the results of the test to the LIS which in turn sends the results to the HIS. The HIS may access a patient&#39;s Lifetime Record that is stored in a database and update the Lifetime Record with the test results. A notification may be sent to the person who entered the test orders that the test results are available for review. 
     Referring to  FIG. 2 , a system for ordering and carrying out a clinical laboratory test within an electronic health record management system includes the addition of a normalization Engine. The Engine may be incorporated into the system at one of several positions. 
     For example, in  FIG. 2   a , an order for a clinical laboratory test is entered into the HIS. The HIS relays the orders to a LIS which is coupled to an instrument. A laboratory technician utilizes the instrument to perform the ordered test on a specimen. The Instrument then relays the results of the test to the Engine which normalizes the results against a reference range. The normalized result is then passed to the LIS which in turn sends the normalized result to the HIS. The HIS may access a patient&#39;s Lifetime Record that is stored in a database and update the Lifetime Record with the normalized result. A notification may be sent to the person who entered the test orders that the test results are available for review. 
     In  FIG. 2   b , the Engine may be configured to receive raw results from the LIS after they are reported from the instrument. The Engine normalized the results and returns the normalized results to the LIS. The LIS then provides the normalizes results to the HIS. As shown in  FIG. 2   c , the engine may be configured to receive raw results from the LIS after they are reported from the instrument. The Engine may then provide the normalized results directly to the HIS rather than to the LIS. Alternatively, as shown in  FIG. 2   d , the Engine may be configured to receive test results from the HIS, normalize those results against a reference range, and pass the normalized values to the database holding the patient&#39;s Lifetime Record. 
     Example 1 
     Referring to  FIG. 3 , a plot of a regression curve is shown for the data below in Table 1. A reference test methodology and instrument, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a normalized value approximating that which would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was blood urea nitrogen. The “gold standard” instrument used for the ‘Y’ method was a Beckman Coulter DXC 880i using the manufacturer&#39;s standard methodology. The second test yielding the ‘X’ values was conducted on a Johnson &amp; Johnson VITROS 5.1 instrument using the manufacturer&#39;s standard methodology. These two methodologies&#39; instruments were used for all tests in the following examples and are consistently referred to as the ‘X’ or ‘Y’ methods or instruments. All reagents were from the same lot numbers by method and manufacturer, and the testing was all conducted on the same day. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 21 
                 23 
               
               
                 2 
                 28 
                 28 
               
               
                 3 
                 16 
                 16 
               
               
                 4 
                 23 
                 22 
               
               
                 5 
                 22 
                 23 
               
               
                 6 
                 10 
                 9 
               
               
                 7 
                 16 
                 15 
               
               
                 8 
                 13 
                 11 
               
               
                 9 
                 25 
                 24 
               
               
                 10 
                 7 
                 6 
               
               
                 11 
                 10 
                 9 
               
               
                 12 
                 23 
                 23 
               
               
                 13 
                 26 
                 25 
               
               
                 14 
                 31 
                 30 
               
               
                 15 
                 14 
                 12 
               
               
                 16 
                 25 
                 23 
               
               
                 17 
                 17 
                 15 
               
               
                 18 
                 39 
                 38 
               
               
                 19 
                 20 
                 19 
               
               
                 20 
                 34 
                 32 
               
               
                 21 
                 11 
                 10 
               
               
                 22 
                 23 
                 21 
               
               
                 23 
                 19 
                 22 
               
               
                 24 
                 25 
                 22 
               
               
                 25 
                 46 
                 45 
               
               
                 26 
                 14 
                 14 
               
               
                 27 
                 13 
                 11 
               
               
                 28 
                 22 
                 20 
               
               
                 29 
                 18 
                 17 
               
               
                 30 
                 16 
                 15 
               
               
                 31 
                 23 
                 22 
               
               
                 32 
                 13 
                 12 
               
               
                 33 
                 18 
                 16 
               
               
                 34 
                 22 
                 17 
               
               
                 35 
                 28 
                 27 
               
               
                 36 
                 18 
                 17 
               
               
                 37 
                 53 
                 49 
               
               
                 38 
                 24 
                 21 
               
               
                 39 
                 19 
                 19 
               
               
                 40 
                 19 
                 17 
               
               
                 81 
                 133 
                 138 
               
               
                 82 
                 28 
                 26 
               
               
                 83 
                 50 
                 48 
               
               
                 84 
                 139 
                 141 
               
               
                 85 
                 119 
                 118 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 1 provides a slope of 0.1025 (with a 95% confidence interval of 1.009 to 1.041) and an intercept of −1.7 (with a 95% confidence interval of −2.4 to −1.1). In this case the a normalized value for a test done on the VITROS 5.1 would be calculated from the equation:
 
 X   m   *M   mfg   +I   mfg   =X   F  
 
where X n , is the value measured on the VITROS 5.1, M mfg  is 1.025, I mfg  is −1.7 and X F  is the normalized value which corresponds to a value that would likely have been measured on the DXC 880i. This normalized value may then be used with reference ranges established for interpreting measurements made with the DXC 880i.
 
     It should be noted that the bias or difference between the measured value and the corresponding value on the reference range is relatively small giving a slope for the regression curve close to 1 and an intercept close to the origin. Several different clinical tests will have small biases including electrolyte measurements. 
     Example 2 
     Referring to  FIG. 4 , a plot of regression curve is shown for the data below in Table 2. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was albumin. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 21 
                 23 
               
               
                 2 
                 28 
                 28 
               
               
                 3 
                 16 
                 16 
               
               
                 4 
                 23 
                 22 
               
               
                 5 
                 22 
                 23 
               
               
                 6 
                 10 
                 9 
               
               
                 7 
                 16 
                 15 
               
               
                 8 
                 13 
                 11 
               
               
                 9 
                 25 
                 24 
               
               
                 10 
                 7 
                 6 
               
               
                 11 
                 10 
                 9 
               
               
                 12 
                 23 
                 23 
               
               
                 13 
                 26 
                 25 
               
               
                 14 
                 31 
                 30 
               
               
                 15 
                 14 
                 12 
               
               
                 16 
                 25 
                 23 
               
               
                 17 
                 17 
                 15 
               
               
                 18 
                 39 
                 38 
               
               
                 19 
                 20 
                 19 
               
               
                 20 
                 34 
                 32 
               
               
                 21 
                 11 
                 10 
               
               
                 22 
                 23 
                 21 
               
               
                 23 
                 19 
                 22 
               
               
                 24 
                 25 
                 22 
               
               
                 25 
                 46 
                 45 
               
               
                 26 
                 14 
                 14 
               
               
                 27 
                 13 
                 11 
               
               
                 28 
                 22 
                 20 
               
               
                 29 
                 18 
                 17 
               
               
                 30 
                 16 
                 15 
               
               
                 31 
                 23 
                 22 
               
               
                 32 
                 13 
                 12 
               
               
                 33 
                 18 
                 16 
               
               
                 34 
                 22 
                 17 
               
               
                 35 
                 28 
                 27 
               
               
                 36 
                 18 
                 17 
               
               
                 37 
                 53 
                 49 
               
               
                 38 
                 24 
                 21 
               
               
                 39 
                 19 
                 19 
               
               
                 40 
                 19 
                 17 
               
               
                 81 
                 133 
                 138 
               
               
                 82 
                 28 
                 26 
               
               
                 83 
                 50 
                 48 
               
               
                 84 
                 139 
                 141 
               
               
                 85 
                 119 
                 118 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 2 provides a slope of 0.841 (with a 95% confidence interval of 0.773 to 0.944) and an intercept of 0.36 (with a 95% confidence interval of 0.03 to 0.70). 
     Example 3 
     Referring to  FIG. 5 , a plot of regression curve is shown for the data below in Table 2. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was high density lipoprotein. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 25 
                 25.9 
               
               
                 2 
                 27 
                 30.7 
               
               
                 3 
                 19 
                 21.9 
               
               
                 4 
                 31 
                 32.9 
               
               
                 5 
                 43 
                 50.1 
               
               
                 6 
                 41 
                 41.3 
               
               
                 7 
                 18 
                 19.9 
               
               
                 8 
                 52 
                 55.5 
               
               
                 9 
                 42 
                 4.8 
               
               
                 10 
                 43 
                 45.8 
               
               
                 11 
                 33 
                 35.1 
               
               
                 12 
                 23 
                 26.1 
               
               
                 13 
                 31 
                 30.2 
               
               
                 14 
                 26 
                 29.9 
               
               
                 15 
                 22 
                 24.8 
               
               
                 16 
                 32 
                 35.1 
               
               
                 17 
                 30 
                 33.6 
               
               
                 18 
                 40 
                 48.4 
               
               
                 19 
                 42 
                 47.6 
               
               
                 20 
                 37 
                 37.8 
               
               
                 21 
                 44 
                 46.5 
               
               
                 22 
                 41 
                 44.7 
               
               
                 23 
                 13 
                 15.2 
               
               
                 24 
                 43 
                 46.8 
               
               
                 25 
                 30 
                 30.3 
               
               
                 26 
                 24 
                 27.1 
               
               
                 27 
                 46 
                 47.4 
               
               
                 28 
                 43 
                 44.6 
               
               
                 29 
                 35 
                 35.7 
               
               
                 30 
                 54 
                 53.8 
               
               
                 31 
                 41 
                 40.5 
               
               
                 32 
                 47 
                 53.1 
               
               
                 33 
                 61 
                 53.4 
               
               
                 34 
                 37 
                 41.3 
               
               
                 35 
                 50 
                 51.9 
               
               
                 36 
                 22 
                 28.9 
               
               
                 37 
                 26 
                 26.4 
               
               
                 38 
                 49 
                 52.2 
               
               
                 39 
                 17 
                 24.1 
               
               
                 40 
                 49 
                 16.7 
               
               
                 62 
                 27 
                 23.3 
               
               
                 63 
                 23 
                 22.9 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 3 provides a slope of 1.032 (with a 95% confidence interval of 0.960 to 1.104) and an intercept of 1.51 (with a 95% confidence interval of −1.1 to 4.1). 
     The standard error estimate is significantly greater than for either of the preceding examples, but the normalized values are still clinically useful for comparison to the reference range. Clinical tests, such as measuring antibodies, provide greater deviation than those for electrolytes as shown by the greater spread of the plotted data and correlation coefficient for the regression curve. These tests may be the ones where regression analysis is more prone to error, but comparison to a reference range is exceptionally useful due to the variance that results from differing instruments and methodologies. 
     Example 4 
     Referring to  FIG. 6 , a plot of regression curve is shown for the data below in Table 4. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was C4 (complement 4). 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 26 
                 31.4 
               
               
                 2 
                 26.9 
                 36.7 
               
               
                 3 
                 17 
                 19.8 
               
               
                 4 
                 8 
                 11.3 
               
               
                 5 
                 25 
                 33.4 
               
               
                 6 
                 18 
                 21.5 
               
               
                 7 
                 28 
                 31.7 
               
               
                 8 
                 6 
                 9.6 
               
               
                 9 
                 33 
                 42 
               
               
                 10 
                 26 
                 30.6 
               
               
                 11 
                 24 
                 32.9 
               
               
                 12 
                 30.3 
                 35.7 
               
               
                 13 
                 38 
                 36.5 
               
               
                 14 
                 27 
                 24.8 
               
               
                 15 
                 19.2 
                 21.2 
               
               
                 16 
                 27.7 
                 29.6 
               
               
                 17 
                 21.8 
                 23.6 
               
               
                 18 
                 34 
                 41 
               
               
                 19 
                 16 
                 19.5 
               
               
                 20 
                 19 
                 22.1 
               
               
                 21 
                 27 
                 36.2 
               
               
                 22 
                 20 
                 24.5 
               
               
                 23 
                 25 
                 30.5 
               
               
                 24 
                 29 
                 35.7 
               
               
                 25 
                 20 
                 26.6 
               
               
                 26 
                 9 
                 11.5 
               
               
                 27 
                 28.2 
                 36.5 
               
               
                 28 
                 47 
                 47 
               
               
                 29 
                 43 
                 57.2 
               
               
                 30 
                 31 
                 35.8 
               
               
                 31 
                 10 
                 15.8 
               
               
                 32 
                 18 
                 20.2 
               
               
                 33 
                 10 
                 12.7 
               
               
                 34 
                 29 
                 35.7 
               
               
                 35 
                 11 
                 12.1 
               
               
                 36 
                 20 
                 22 
               
               
                 37 
                 24 
                 27.3 
               
               
                 38 
                 10 
                 13 
               
               
                 39 
                 12 
                 13.3 
               
               
                 40 
                 7 
                 9.2 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 4 provides a slope of 1.158 (with a 95% confidence interval of 1.050 to 1.291) and an intercept of 0.88 (with a 95% confidence interval of −1.78 to 3.53). 
     Example 5 
     Referring to  FIG. 7 , a plot of regression curve is shown for the data below in Table 5. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was haptoglobin. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 645 
                 600 
               
               
                 2 
                 197 
                 243 
               
               
                 3 
                 151 
                 175 
               
               
                 4 
                 229 
                 264 
               
               
                 5 
                 246 
                 257 
               
               
                 5 
                 213 
                 211 
               
               
                 7 
                 328 
                 318 
               
               
                 8 
                 354 
                 289 
               
               
                 9 
                 235 
                 255 
               
               
                 10 
                 21 
                 23 
               
               
                 11 
                 124 
                 128 
               
               
                 12 
                 94 
                 88 
               
               
                 13 
                 184 
                 168 
               
               
                 14 
                 183 
                 193 
               
               
                 15 
                 310 
                 276 
               
               
                 16 
                 207 
                 154 
               
               
                 17 
                 222 
                 224 
               
               
                 18 
                 113 
                 111 
               
               
                 19 
                 14 
                 3 
               
               
                 20 
                 164 
                 188 
               
               
                 21 
                 60 
                 58 
               
               
                 22 
                 24 
                 24 
               
               
                 23 
                 178 
                 157 
               
               
                 24 
                 327 
                 384 
               
               
                 25 
                 333 
                 304 
               
               
                 28 
                 152 
                 159 
               
               
                 28 
                 221 
                 228 
               
               
                 29 
                 179 
                 186 
               
               
                 30 
                 157 
                 147 
               
               
                 31 
                 63  
                 56 
               
               
                 32 
                 93  
                 99 
               
               
                 33 
                 201 
                 225 
               
               
                 34 
                 189 
                 199 
               
               
                 36 
                 16  
                 16 
               
               
                 37 
                 133 
                 174 
               
               
                 38 
                 120 
                 144 
               
               
                 39 
                 147 
                 156 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 5 provides a slope of 0.959 (with a 95% confidence interval of 0.889 to 1.029) and an intercept of 8.5 (with a 95% confidence interval of −6.8 to 23.8). 
     Example 6 
     Referring to  FIG. 8 , a plot of regression curve is shown for the data below in Table 6. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was potassium. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.6 
                 4.4 
               
               
                 2 
                 3.7 
                 3.7 
               
               
                 3 
                 2.8 
                 2.7 
               
               
                 4 
                 3.7 
                 3.7 
               
               
                 5 
                 2.8 
                 2.8 
               
               
                 6 
                 4.2 
                 4.2 
               
               
                 7 
                 2.8 
                 2.7 
               
               
                 8 
                 5.7 
                 5.6 
               
               
                 9 
                 4 
                 3.9 
               
               
                 10 
                 4.2 
                 4.1 
               
               
                 11 
                 4 
                 3.9 
               
               
                 12 
                 2.8 
                 2.8 
               
               
                 13 
                 4 
                 4.0 
               
               
                 14 
                 3.7 
                 3.7 
               
               
                 15 
                 4.1 
                 4.1 
               
               
                 16 
                 4 
                 4.0 
               
               
                 17 
                 4.2 
                 4.3 
               
               
                 18 
                 4.2 
                 4.2 
               
               
                 19 
                 4.8 
                 4.8 
               
               
                 20 
                 3.8 
                 3.8 
               
               
                 21 
                 4.3 
                 4.4 
               
               
                 22 
                 4.2 
                 4.2 
               
               
                 23 
                 2.1 
                 2.3 
               
               
                 24 
                 4.4 
                 4.3 
               
               
                 25 
                 3.6 
                 3.5 
               
               
                 26 
                 4.5 
                 4.4 
               
               
                 27 
                 4.2 
                 4.1 
               
               
                 28 
                 4.7 
                 4.6 
               
               
                 29 
                 4.5 
                 4.4 
               
               
                 30 
                 5.3 
                 5.2 
               
               
                 31 
                 4.6 
                 4.5 
               
               
                 32 
                 4.9 
                 4.8 
               
               
                 33 
                 4.5 
                 4.5 
               
               
                 34 
                 4.3 
                 4.4 
               
               
                 35 
                 4.1 
                 4.0 
               
               
                 36 
                 3.9 
                 3.9 
               
               
                 37 
                 4.1 
                 4.1 
               
               
                 38 
                 4.1 
                 4.1 
               
               
                 39 
                 3.8 
                 3.7 
               
               
                 40 
                 3.9 
                 3.9 
               
               
                 51 
                 7.4 
                 6.9 
               
               
                 52 
                 3.3 
                 3.4 
               
               
                 53 
                 3.2 
                 3.3 
               
               
                 54 
                 4.1 
                 4.2 
               
               
                 55 
                 1.8 
                 1.8 
               
               
                 57 
                 2.6 
                 2.6 
               
               
                 58 
                 4 
                 4.1 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 6 provides a slope of 0.935 (with a 95% confidence interval of 0.906 to 0.963) and an intercept of 0.23 (with a 95% confidence interval of 0.11 to 0.35). 
     Example 7 
     Referring to  FIG. 9 , a plot of regression curve is shown for the data below in Table 7. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was low density lipoprotein. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 929  
                 315 
               
               
                 3 
                 1318 
                 387 
               
               
                 4 
                 605 
                 197 
               
               
                 5 
                 476  
                 154 
               
               
                 6 
                 595  
                 192 
               
               
                 7 
                 368  
                 129 
               
               
                 8 
                 1196 
                 447 
               
               
                 9 
                 545  
                 180 
               
               
                 10 
                 762 
                 248 
               
               
                 11 
                 468 
                 152 
               
               
                 12 
                 516 
                 175 
               
               
                 13 
                 626 
                 210 
               
               
                 14 
                 620 
                 212 
               
               
                 15 
                 549 
                 187 
               
               
                 16 
                 1046 
                 365 
               
               
                 17 
                 521  
                 182 
               
               
                 18 
                 495  
                 172 
               
               
                 19 
                 579  
                 198 
               
               
                 20 
                 588  
                 197 
               
               
                 21 
                 514  
                 170 
               
               
                 22 
                 630  
                 214 
               
               
                 23 
                 283 
                 122 
               
               
                 24 
                 710 
                 258 
               
               
                 25 
                 824 
                 286 
               
               
                 26 
                 616 
                 211 
               
               
                 27 
                 529  
                 174 
               
               
                 28 
                 787  
                 272 
               
               
                 29 
                 626  
                 208 
               
               
                 30 
                 887  
                 332 
               
               
                 31 
                 613 
                 206 
               
               
                 32 
                 512  
                 189 
               
               
                 33 
                 731 
                 244 
               
               
                 34 
                 651 
                 200 
               
               
                 35 
                 677 
                 233 
               
               
                 36 
                 593 
                 205 
               
               
                 37 
                 1098 
                 394 
               
               
                 38 
                 547 
                 181 
               
               
                 39 
                 618 
                 219 
               
               
                 40 
                 520 
                 186 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 7 provides a slope of 0.339 (with a 95% confidence interval of 0.315 to 0.363) and an intercept of 1.3 (with a 95% confidence interval of −15.3 to 17.9). 
     Example 8 
     Referring to  FIG. 10 , a plot of regression curve is shown for the data below in Table 8. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was a blood lipid level. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 29 
                 11 
               
               
                 2 
                 62 
                 15 
               
               
                 3 
                 73 
                 18 
               
               
                 4 
                 75 
                 23 
               
               
                 5 
                 44 
                 17 
               
               
                 7 
                 78 
                 19 
               
               
                 8 
                 73 
                 18 
               
               
                 8 
                 86 
                 20 
               
               
                 9 
                 247 
                 39 
               
               
                 10 
                 68 
                 23 
               
               
                 11 
                 54 
                 15 
               
               
                 12 
                 50 
                 16 
               
               
                 13 
                 120 
                 26 
               
               
                 14 
                 483 
                 66 
               
               
                 15 
                 34 
                 15 
               
               
                 17 
                 83 
                 22 
               
               
                 18 
                 172 
                 33 
               
               
                 18 
                 206 
                 43 
               
               
                 19 
                 69 
                 19 
               
               
                 20 
                 138 
                 27 
               
               
                 21 
                 84 
                 25 
               
               
                 22 
                 122 
                 27 
               
               
                 23 
                 60 
                 18 
               
               
                 24 
                 188 
                 39 
               
               
                 25 
                 191 
                 34 
               
               
                 26 
                 656 
                 108 
               
               
                 27 
                 313 
                 54 
               
               
                 28 
                 289 
                 47 
               
               
                 29 
                 143 
                 27 
               
               
                 30 
                 77  
                 20 
               
               
                 31 
                 135 
                 28 
               
               
                 32 
                 28  
                 15 
               
               
                 33 
                 86  
                 27 
               
               
                 34 
                 132 
                 33 
               
               
                 35 
                 244 
                 45 
               
               
                 36 
                 40  
                 15 
               
               
                 37 
                 26  
                 13 
               
               
                 38 
                 202 
                 34 
               
               
                 39 
                 126 
                 29 
               
               
                 40 
                 191 
                 36 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 8 provides a slope of 0.136 (with a 95% confidence interval of 0.128 to 0.144) and an intercept of 10.1 (with a 95% confidence interval of 8.6 to 11.6). 
     Example 9 
     Referring to  FIG. 11 , a plot of regression curve is shown for the data below in Table 9. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was magnesium. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 9 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 1.3 
                 1.62 
               
               
                 2 
                 1.7 
                 2.05 
               
               
                 3 
                 1.1 
                 1.44 
               
               
                 4 
                 1.9 
                 2.27 
               
               
                 5 
                 1.2 
                 1.45 
               
               
                 6 
                 1.5 
                 1.90 
               
               
                 7 
                 1 
                 1.38 
               
               
                 8 
                 1.8 
                 2.29 
               
               
                 9 
                 1.6 
                 2.01 
               
               
                 10 
                 1.7 
                 2.09 
               
               
                 11 
                 1.8 
                 2.13 
               
               
                 12 
                 1 
                 1.37 
               
               
                 13 
                 1.5 
                 1.82 
               
               
                 14 
                 1.5 
                 1.84 
               
               
                 15 
                 1.2 
                 1.59 
               
               
                 16 
                 1.9 
                 2.27 
               
               
                 17 
                 1.5 
                 1.91 
               
               
                 18 
                 2.0 
                 2.35 
               
               
                 19 
                 1.4 
                 1.87 
               
               
                 20 
                 1.9 
                 2.21 
               
               
                 21 
                 1.6 
                 1.98 
               
               
                 22 
                 1.6 
                 1.94 
               
               
                 23 
                 0.8 
                 1.25 
               
               
                 24 
                 1.7 
                 2.12 
               
               
                 25 
                 1.7 
                 2.05 
               
               
                 26 
                 2.1 
                 2.37 
               
               
                 27 
                 1.7 
                 2.10 
               
               
                 28 
                 2.0 
                 2.23 
               
               
                 29 
                 2.0 
                 2.41 
               
               
                 30 
                 1.8 
                 2.25 
               
               
                 31 
                 1.6 
                 1.99 
               
               
                 32 
                 1.9 
                 2.38 
               
               
                 33 
                 1.9 
                 2.44 
               
               
                 34 
                 2.0 
                 2.39 
               
               
                 35 
                 1.9 
                 2.31 
               
               
                 36 
                 1.9 
                 2.15 
               
               
                 37 
                 1.7 
                 2.21 
               
               
                 38 
                 2.1 
                 2.53 
               
               
                 39 
                 1.5 
                 1.93 
               
               
                 40 
                 1.8 
                 2.35 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 9 provides a slope of 0.1031 (with a 95% confidence interval of 0.955 to 1.107) and an intercept of 0.335 (with a 95% confidence interval of 0.208 to 0.463). 
     Example 10 
     Referring to  FIG. 12 , a plot of regression curve is shown for the data below in Table 10. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was sodium. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 10 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 2 
                 124 
                 123 
               
               
                 4 
                 144 
                 142 
               
               
                 5 
                 142 
                 142 
               
               
                 6 
                 144 
                 142 
               
               
                 7 
                 102 
                 103 
               
               
                 8 
                 141 
                 138 
               
               
                 9 
                 142 
                 139 
               
               
                 10 
                 139 
                 137 
               
               
                 11 
                 140 
                 137 
               
               
                 13 
                 138 
                 136 
               
               
                 14 
                 138 
                 136 
               
               
                 15 
                 142 
                 141 
               
               
                 16 
                 140 
                 139 
               
               
                 17 
                 140 
                 140 
               
               
                 18 
                 140 
                 138 
               
               
                 19 
                 140 
                 139 
               
               
                 20 
                 140 
                 139 
               
               
                 21 
                 141 
                 140 
               
               
                 22 
                 138 
                 137 
               
               
                 24 
                 141 
                 139 
               
               
                 25 
                 139 
                 137 
               
               
                 26 
                 147 
                 144 
               
               
                 27 
                 143 
                 140 
               
               
                 28 
                 140 
                 139 
               
               
                 29 
                 138 
                 137 
               
               
                 30 
                 143 
                 139 
               
               
                 31 
                 143 
                 140 
               
               
                 32 
                 145 
                 143 
               
               
                 33 
                 144 
                 142 
               
               
                 34 
                 142 
                 141 
               
               
                 35 
                 137 
                 135 
               
               
                 36 
                 137 
                 135 
               
               
                 37 
                 138 
                 138 
               
               
                 38 
                 138 
                 137 
               
               
                 39 
                 135 
                 133 
               
               
                 40 
                 144 
                 137 
               
               
                 51 
                 126 
                 119 
               
               
                 52 
                 132 
                 137 
               
               
                 53 
                 137 
                 139 
               
               
                 54 
                 185 
                 169 
               
               
                 55 
                 135 
                 138 
               
               
                 55 
                 132 
                 136 
               
               
                 57 
                 130 
                 133 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 10 provides a slope of 0.1009 (with a 95% confidence interval of 0.917 to 1.101) and an intercept of −2.4 (with a 95% confidence interval of −15.2 to 10.4). 
     Example 11 
     Referring to  FIG. 13 , a plot of regression curve is shown for the data below in Table 11. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was pre-albumin. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 11 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 11.6 
                 12.6 
               
               
                 2 
                 8.6  
                 8.8 
               
               
                 3 
                 11.3 
                 8 
               
               
                 4 
                 11.6 
                 13.4 
               
               
                 5 
                 22.9 
                 21.5 
               
               
                 6 
                 6.4  
                 9.4 
               
               
                 7 
                 12.1 
                 9.8 
               
               
                 8 
                 9.1 
                 10.3 
               
               
                 9 
                 5.4 
                 8.3 
               
               
                 10 
                 36.8 
                 38.4 
               
               
                 11 
                 15.8 
                 19.3 
               
               
                 12 
                 22.1 
                 22.2 
               
               
                 13 
                 15.5 
                 17.8 
               
               
                 14 
                 32.9 
                 39.4 
               
               
                 15 
                 10.5 
                 12 
               
               
                 16 
                 17.2 
                 19.2 
               
               
                 17 
                 18.2 
                 19.7 
               
               
                 18 
                 16.6 
                 17.3 
               
               
                 19 
                 20 
                 28.8 
               
               
                 20 
                 22.9 
                 26.4 
               
               
                 21 
                 11.1 
                 12.8 
               
               
                 22 
                 12.6 
                 13.7 
               
               
                 23 
                 19.6 
                 22.1 
               
               
                 24 
                 17.4 
                 17.3 
               
               
                 25 
                 22.8 
                 23.8 
               
               
                 26 
                 35.9 
                 42.5 
               
               
                 27 
                 21.2 
                 25.2 
               
               
                 28 
                 13.6 
                 14.3 
               
               
                 28 
                 12.3 
                 12.5 
               
               
                 30 
                 8.3  
                 11.5 
               
               
                 31 
                 9.1 
                 13.7 
               
               
                 32 
                 6.3 
                 7.8 
               
               
                 33 
                 23.3 
                 26.2 
               
               
                 34 
                 9.9 
                 12 
               
               
                 35 
                 21.1 
                 22.3 
               
               
                 36 
                 31.1 
                 39.7 
               
               
                 37 
                 34.2 
                 42.4 
               
               
                 38 
                 11.6 
                 13.3 
               
               
                 39 
                 8.4  
                 10.2 
               
               
                 40 
                 11.5 
                 13.1 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 11 provides a slope of 1.185 (with a 95% confidence interval of 1.100 to 1.270) and an intercept of −0.95 (with a 95% confidence interval of −2.54 to 0.63). 
     Example 12 
     Referring to  FIG. 14 , a plot of regression curve is shown for the data below in Table 12. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was phosphorus. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 12 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.1  
                 3.9 
               
               
                 2 
                 5.0 
                 5.0 
               
               
                 3 
                 3.0 
                 2.8 
               
               
                 4 
                 3.7 
                 3.4 
               
               
                 5 
                 2.3  
                 2.2 
               
               
                 7 
                 2.6 
                 2.4 
               
               
                 8 
                 4 
                 3.9 
               
               
                 8 
                 4.2  
                 3.9 
               
               
                 9 
                 4.4 
                 4.2 
               
               
                 10 
                 3.4 
                 3.2 
               
               
                 11 
                 3.9 
                 3.7 
               
               
                 12 
                 3 
                 2.8 
               
               
                 13 
                 3.2 
                 3.2 
               
               
                 14 
                 2.8 
                 2.6 
               
               
                 15 
                 3.8 
                 3.3 
               
               
                 16 
                 4.6 
                 4.4 
               
               
                 17 
                 4.2 
                 4.0 
               
               
                 18 
                 4.9 
                 5.0 
               
               
                 19 
                 4.8 
                 4.6 
               
               
                 20 
                 4.8 
                 4.6 
               
               
                 21 
                 3.4 
                 3.2 
               
               
                 22 
                 3.6 
                 3.5 
               
               
                 23 
                 1.7 
                 1.8 
               
               
                 24 
                 3.3 
                 3.2 
               
               
                 25 
                 4.5 
                 4.4 
               
               
                 26 
                 3.3 
                 3.0 
               
               
                 27 
                 3.6 
                 3.4 
               
               
                 28 
                 5.5 
                 5.4 
               
               
                 29 
                 4.3 
                 4.2 
               
               
                 30 
                 3.6 
                 3.4 
               
               
                 31 
                 4.1 
                 4.0 
               
               
                 32 
                 3.8 
                 3.7 
               
               
                 33 
                 4.6 
                 4.6 
               
               
                 34 
                 3.9 
                 3.7 
               
               
                 36 
                 4.8 
                 4.8 
               
               
                 36 
                 3.1 
                 3.0 
               
               
                 37 
                 4.2 
                 4.0 
               
               
                 38 
                 4.2 
                 4.1 
               
               
                 39 
                 3.0 
                 3.1 
               
               
                 40 
                 4.2 
                 4.8 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 12 provides a slope of 1.039 (with a 95% confidence interval of 0.973 to 1.104) and an intercept of −0.26 (with a 95% confidence interval of −0.52 to −0.01). 
     Example 13 
     Referring to  FIG. 15 , a plot of regression curve is shown for the data below in Table 13. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was total bilirubin. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 13 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 0.1 
                 0.5 
               
               
                 2 
                 0.2 
                 0.7 
               
               
                 3 
                 0.1 
                 0.6 
               
               
                 4 
                 0.2 
                 0.6 
               
               
                 5 
                 0.5 
                 1.0 
               
               
                 6 
                 0.1  
                 0.6 
               
               
                 7 
                 0.1 
                 0.4 
               
               
                 8 
                 1.3 
                 1.2 
               
               
                 9 
                 0.3 
                 0.6 
               
               
                 10 
                 0.5 
                 0.7 
               
               
                 11 
                 0.1 
                 0.2 
               
               
                 12 
                 0.1 
                 0.3 
               
               
                 13 
                 3.1 
                 3.9 
               
               
                 14 
                 0.7 
                 0.9 
               
               
                 15 
                 0.2 
                 0.6 
               
               
                 17 
                 0.6 
                 0.9 
               
               
                 18 
                 0.4  
                 0.5 
               
               
                 18 
                 2 
                 2.6 
               
               
                 19 
                 1.2 
                 1.7 
               
               
                 20 
                 0.5 
                 0.8 
               
               
                 21 
                 1 
                 1.5 
               
               
                 22 
                 0.3 
                 0.8 
               
               
                 23 
                 0.7 
                 1.3 
               
               
                 24 
                 0.6  
                 0.8 
               
               
                 25 
                 0.4 
                 0.8 
               
               
                 26 
                 0.2  
                 0.7 
               
               
                 27 
                 0.3  
                 0.7 
               
               
                 28 
                 0.3  
                 0.5 
               
               
                 30 
                 0.8 
                 1.5 
               
               
                 31 
                 0.1 
                 0.4 
               
               
                 32 
                 0.6 
                 0.9 
               
               
                 33 
                 0.6  
                 0.8 
               
               
                 34 
                 0.6 
                 0.6 
               
               
                 35 
                 0.2 
                 0.4 
               
               
                 36 
                 0.3 
                 0.5 
               
               
                 37 
                 1.2  
                 1.7 
               
               
                 38 
                 1.2  
                 1.5 
               
               
                 39 
                 7.0 
                 8.3 
               
               
                 40 
                 18.2 
                 21.8 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 13 provides a slope of 1.180 (with a 95% confidence interval of 1.160 to 1.180) and an intercept of 0.24 (with a 95% confidence interval of 0.18 to 0.31). 
     Example 14 
     Referring to  FIG. 16 , a plot of regression curve is shown for the data below in Table 14. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was a triglyceride level. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 14 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 91 
                 85 
               
               
                 2 
                 136  
                 128 
               
               
                 3 
                 138 
                 136 
               
               
                 4 
                 246 
                 225 
               
               
                 5 
                 65 
                 57 
               
               
                 6 
                 238 
                 225 
               
               
                 7 
                 131 
                 122 
               
               
                 8 
                 121 
                 100 
               
               
                 9 
                 108 
                 94 
               
               
                 10  
                 74  
                 64 
               
               
                 11 
                 512 
                 482 
               
               
                 12 
                 57 
                 51 
               
               
                 13 
                 89  
                 82 
               
               
                 14  
                 63 
                 57 
               
               
                 15 
                 96 
                 86 
               
               
                 16  
                 77 
                 73 
               
               
                 17 
                 130 
                 118 
               
               
                 18  
                 103 
                 94 
               
               
                 19  
                 151 
                 136 
               
               
                 20  
                 144 
                 134 
               
               
                 21  
                 75  
                 66 
               
               
                 22  
                 87  
                 80 
               
               
                 23  
                 109 
                 124 
               
               
                 24  
                 118 
                 103 
               
               
                 25  
                 119 
                 102 
               
               
                 26  
                 194 
                 171 
               
               
                 27  
                 137 
                 120 
               
               
                 28  
                 188 
                 162 
               
               
                 29  
                 149 
                 131 
               
               
                 30  
                 235 
                 204 
               
               
                 31  
                 260 
                 234 
               
               
                 32  
                 79 
                 73 
               
               
                 33 
                 138 
                 129 
               
               
                 34  
                 151 
                 143 
               
               
                 35 
                 170 
                 159 
               
               
                 36  
                 149 
                 144 
               
               
                 37  
                 103 
                 98 
               
               
                 38  
                 79  
                 72 
               
               
                 39  
                 100 
                 95 
               
               
                 40  
                 175 
                 163 
               
               
                 81  
                 164 
                 168 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 14 provides a slope of 0.936 (with a 95% confidence interval of 0.907 to 0.964) and an intercept of −2.1 (with a 95% confidence interval of −6.7 to 2.5). 
     Example 15 
     Referring to  FIG. 17 , a plot of regression curve is shown for the data below in Table 15. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was total protein. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 15 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 3.8  
                 3.7 
               
               
                 2 
                 4.6  
                 4.4 
               
               
                 3 
                 3.9  
                 3.7 
               
               
                 4 
                 6.5 
                 6.2 
               
               
                 5 
                 4.4  
                 4.2 
               
               
                 6 
                 6.6  
                 6.0 
               
               
                 7 
                 4.3  
                 4.3 
               
               
                 8 
                 8.3  
                 7.1 
               
               
                 9 
                 6.8  
                 6.6 
               
               
                 10 
                 6.9 
                 6.5 
               
               
                 11 
                 6.6 
                 6.3 
               
               
                 12 
                 3.4  
                 3.3 
               
               
                 13 
                 6.1 
                 6.1 
               
               
                 14 
                 5.8 
                 5.7 
               
               
                 15 
                 5.8  
                 5.8 
               
               
                 16 
                 5.5 
                 5.4 
               
               
                 17 
                 5.3 
                 5.9 
               
               
                 18 
                 6.4  
                 8.2 
               
               
                 19 
                 8.5 
                 6.1 
               
               
                 20 
                 5.9 
                 5.8 
               
               
                 21 
                 6.7 
                 6.6 
               
               
                 22 
                 5.9 
                 5.7 
               
               
                 23 
                 2.6 
                 2.8 
               
               
                 24 
                 7.1 
                 6.8 
               
               
                 25 
                 6.0 
                 5.7 
               
               
                 26 
                 6.5  
                 6.2 
               
               
                 27 
                 7.1  
                 6.7 
               
               
                 28 
                 6.6  
                 6.5 
               
               
                 29 
                 6.4  
                 6.1 
               
               
                 30 
                 8.1 
                 7.0 
               
               
                 31 
                 7.3 
                 6.9 
               
               
                 32 
                 7.7 
                 7.3 
               
               
                 33 
                 7.8 
                 7.2 
               
               
                 34 
                 7.1  
                 7.1 
               
               
                 35 
                 6.9  
                 6.7 
               
               
                 36 
                 5.9  
                 6.0 
               
               
                 37 
                 6.5  
                 6.1 
               
               
                 38 
                 7.4  
                 7.1 
               
               
                 39 
                 6.0  
                 5.9 
               
               
                 40 
                 7.6  
                 6.9 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 15 provides a slope of 0.874 (with a 95% confidence interval of 0.820 to 0.928) and an intercept of 0.51 (with a 95% confidence interval of 0.17 to 0.85). 
     Example 16 
     Referring to  FIG. 18 , a plot of regression curve is shown for the data below in Table 16. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was transferrin. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 16 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 205 
                 209.2 
               
               
                 2 
                 255 
                 251.4 
               
               
                 3 
                 224 
                 222.3 
               
               
                 4 
                 110 
                 110.5 
               
               
                 5 
                 155 
                 149.1 
               
               
                 5 
                 152 
                 158.8 
               
               
                 7 
                 195 
                 170.7 
               
               
                 8 
                 149 
                 151.7 
               
               
                 9 
                 182 
                 164 
               
               
                 10 
                 226 
                 220.5 
               
               
                 11 
                 293 
                 295 
               
               
                 12 
                 123 
                 124.8 
               
               
                 13 
                 197 
                 197.1 
               
               
                 14 
                 292 
                 279.1 
               
               
                 15 
                 282 
                 282.8 
               
               
                 16 
                 200 
                 198.5 
               
               
                 17 
                 233 
                 234.7 
               
               
                 18 
                 179 
                 174.4 
               
               
                 19 
                 249 
                 247.3 
               
               
                 20 
                 275 
                 283.5 
               
               
                 21 
                 301 
                 301.9 
               
               
                 22 
                 313 
                 308.5 
               
               
                 23 
                 99 
                 101.2 
               
               
                 24 
                 173 
                 175.9 
               
               
                 25 
                 109 
                 112.6 
               
               
                 26 
                 274 
                 259.4 
               
               
                 27 
                 370 
                 370.9 
               
               
                 28 
                 148 
                 150.3 
               
               
                 29 
                 149 
                 151.5 
               
               
                 30 
                 315 
                 321.2 
               
               
                 31 
                 134 
                 132.7 
               
               
                 32 
                 330 
                 326.4 
               
               
                 33 
                 294 
                 282.3 
               
               
                 34 
                 229 
                 224.9 
               
               
                 35 
                 163 
                 163 
               
               
                 36 
                 180 
                 180.7 
               
               
                 37 
                 244 
                 248 
               
               
                 38 
                 243 
                 243.6 
               
               
                 39 
                 167 
                 166.4 
               
               
                 40 
                 245 
                 255.2 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 16 provides a slope of 0.997 (with a 95% confidence interval of 0.964 to 1.030) and an intercept of −0.93 (with a 95% confidence interval of −8.34 to 6.48). 
     Example 17 
     Referring to  FIG. 19 , a plot of regression curve is shown for the data below in Table 17. A reference test, i.e. a “gold standard”, is used to provide a reference measurement for a specimen. A second test is also performed using a different instrument and methodology to provide a second measured value. Deming regression was used to provide a linear equation that can in turn be used to calculate a reference, or normalized value, that would be obtained by using the “gold standard” from a value measured by the second methodology. In this case, the clinically significant parameter being measured was uric acid. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 17 
               
               
                   
               
               
                 Specimen 
                 X 
                 Y 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 4.2 
                 4.5 
               
               
                 2 
                 7.8 
                 8.1 
               
               
                 3 
                 4.8 
                 6.1 
               
               
                 4 
                 4.5 
                 4.7 
               
               
                 5 
                 2.6 
                 3.0 
               
               
                 6 
                 5.2 
                 5.3 
               
               
                 7 
                 3.9 
                 4.1 
               
               
                 8 
                 3.7 
                 4.6 
               
               
                 9 
                 4.2 
                 4.4 
               
               
                 10 
                 2.4 
                 2.7 
               
               
                 11 
                 4.7 
                 4.8 
               
               
                 12 
                 3.9 
                 4.2 
               
               
                 13 
                 5.3 
                 5.5 
               
               
                 14 
                 5.9 
                 6.0 
               
               
                 15 
                 3.2 
                 3.4 
               
               
                 16 
                 5.2 
                 5.5 
               
               
                 17 
                 5.5 
                 5.8 
               
               
                 18 
                 5.3 
                 5.8 
               
               
                 19 
                 5.5 
                 5.9 
               
               
                 20 
                 8.7 
                 8.8 
               
               
                 21 
                 8.3 
                 8.6 
               
               
                 22 
                 5.5 
                 5.6 
               
               
                 23 
                 3.5 
                 4.4 
               
               
                 24 
                 4.8 
                 5.0 
               
               
                 25 
                 7.4 
                 7.5 
               
               
                 26 
                 6.8 
                 6.9 
               
               
                 27 
                 4.8 
                 5.0 
               
               
                 28 
                 4.3 
                 4.3 
               
               
                 29 
                 6.8 
                 7.1 
               
               
                 30 
                 5.2 
                 5.7 
               
               
                 31 
                 6.7 
                 6.9 
               
               
                 32 
                 4.0 
                 4.3 
               
               
                 33 
                 5.8 
                 6.1 
               
               
                 34 
                 4.2 
                 4.6 
               
               
                 35 
                 4.6 
                 4.8 
               
               
                 36 
                 5.1 
                 5.8 
               
               
                 37 
                 2.7 
                 3.1 
               
               
                 38 
                 8.5 
                 8.8 
               
               
                 39 
                 4.1 
                 4.2 
               
               
                 40 
                 4.1 
                 4.0 
               
               
                   
               
             
          
         
       
     
     A Deming regression analysis of the data shown in Table 17 provides a slope of 0.980 (with a 95% confidence interval of 0.937 to 1.023) and an intercept of 0.37 (with a 95% confidence interval of 0.14 to 0.60).