Patent Description:
The patent publication <CIT> further describes methods, monitors and systems for advanced detection of sepsis in a subject.

The present disclosure relates to methods for detecting an infection, including infections resulting in sepsis, by using vital signs combined with parameters measured by a hematology analyzer. Measuring systolic blood pressure alone or in combination with additional hematology parameters has been found to improve sepsis predictive accuracy.

Sepsis is a systemic inflammatory response to an infection that can quickly spiral into a life-threatening condition. Patient mortality increases by <NUM>% with each hour that passes without diagnosis, and treatment. In the past, the diagnosis of sepsis has been hindered from lack of a clear definition and both timely and accurate diagnosis. Sepsis is now the number <NUM> cost of hospitalization, and <NUM>rd leading cause of death in the United States alone.

In <NUM> the first definition of sepsis was published, in which systemic inflammatory response syndrome (SIRS) was proposed to define the condition. SIRS occurs when two or more of the following criteria are met: a temperature greater than <NUM> degrees Celsius (C) or less than <NUM> degrees C, a heart rate greater than <NUM> beats per minute (bpm), a respiratory rate greater than <NUM> breaths per minute (breaths/min), or a white blood cell count (WBC) less than <NUM>,<NUM> per microliter of blood (<NUM>,<NUM> /mm<NUM>) (leukopenia) or greater than <NUM>,<NUM>/mm<NUM> (leukocytosis). At the time, sepsis was defined as a condition which occurs when <NUM> or more SIRS criteria are met, and an infection persists in the body. However, the condition of sepsis is still not well understood, and this definition has subsequently undergone alterations. In <NUM> this definition, "Sepsis-<NUM>," was updated and is now referred to as "Sepsis-<NUM>," which in includes organ dysfunction. Instead of SIRS, a "sequential organ failure assessment" (SOFA) was proposed which, due to its extensiveness, is often initially evaluated by a quick SOFA (qSOFA) first. In a hospital setting, a quick sequential organ failure assessment is administered first. If a qSOFA indicates that a patient is at risk of sepsis, then a full SOFA test may be administered.

Like SIRS, qSOFA also assesses patient vital signs. With a sensitivity as much as <NUM>%, SIRS is far more sensitive than qSOFA which has a sensitivity of <NUM>%. However, at <NUM>%, qSOFA has a much higher specificity than SIRS which is about <NUM>% specific for sepsis. Despite its high sensitivity, SIRS has still been shown to leave out about <NUM>% of patients with sepsis (<NUM> in <NUM>) who did not test positive for at least <NUM> SIRS criteria. Neither qSOFA nor SIRS have sufficient performance to consistently help health professionals identify sepsis early and without waiting for any laboratory results. Furthermore, if a patient does not present outward signs of inflammation, it might not be apparent to utilize these criteria. This is crucial, as these signs may not be displayed for several, critical hours.

Biomarkers, such as procalcitonin (PCT) and C-reactive protein (CRP), have previously been identified as another tool capable of indicating sepsis, yet such biomarkers still lack the specificity and sensitivity to detect all sepsis cases. PCT, with a sensitivity and specificity of about <NUM>% and <NUM>%, respectively, is widely thought to be the most reliable of these biomarkers yet can still yield both false positive and false negative results. Additionally, PCT cannot consistently differentiate sepsis from non-infectious cases. PCT is further hindered by cost and is only ordered by a clinician when the patient is already showing outward signs of inflammation. There can be a significant delay before a patent shows signs of inflammation, especially in particular infections where organ dysfunction does not generate a systemic host response. These factors prevent the use of PCT for early diagnosis of sepsis, and a patient may be in life-threatening condition before the test is ordered.

An increased WBC is, in general, associated with bacterial infection, but a significant patient population has been shown not to exhibit this change, thus leaving out a critical number of at-risk patients. Furthermore, elevated WBC is associated with a variety of other conditions such as trauma or severe burn, so WBC alone is not useful in sepsis diagnosis. Other laboratory tests including complete blood count with differential (CBC-diff), serum lactate, erythrocyte sedimentation rate (ESR), and bacterial cultures have also been used in the past to diagnose sepsis, but also lack sufficient specificity and sensitivity, and can be further hindered by the high cost or the length of time that it takes to complete these tests.

More recently, an additional hematology analyzer parameter, monocyte distribution width (MDW), has been shown to indicate sepsis, with a sensitivity and specificity of <NUM>% and <NUM>%, respectively, and is especially efficacious when combined with other measurements associated with infection, such as WBC. The use of this tool is particularly advantageous, as this value is measured on all patient samples, therefore these hematology parameters may be useful in detecting sepsis even before a patient displays outward signs of inflammation. However, there is still a need to improve the specificity and sensitivity of laboratory testing for sepsis to further reduce the number of patients who experience delayed diagnosis and treatment.

For these and other reasons, improved methods or systems for identifying infection and sepsis, are desirable.

In the past, the assessment of sepsis, or the probability of developing sepsis, has been hindered by a lack of a clear definition and a timely diagnostic tool that is acceptably sensitive and specific. In addition to SIRS criteria and various biomarkers, sepsis may be assessed in part by evaluating the MDW measured from a blood sample. Exemplary methods are disclosed, for example, in PCT Patent Application No. <CIT> and <CIT>. Embodiments of present disclosure may improve the predictive ability of MDW through combination with WBC and vital signs. A system to evaluate the infection status may involve any of the methods described herein.

Sepsis is a systemic inflammatory response to an infection that can become life-threatening. Sepsis arises when the body's response to an infection is out of balance, and the chemicals released into the bloodstream to fight an infection lead to inflammation and severely injure the body's own tissues and organs. In the most severe cases, this can lead to septic shock (at this time, also referred to as "sepsis-<NUM>"), where circulatory and cellular damage drastically increase mortality.

Sepsis is a complicated condition and is continuously being redefined. In <NUM>, the Third International Consensus Definitions for sepsis and sepsis were redefined. Due to poor specificity and sensitivity SIRS was replaced by SOFA which, due to its extensiveness, is initially evaluated by a qSOFA score. A qSOFA is scored on a scale from <NUM>-<NUM> points, with <NUM> point for each vital sign that tests positively. These qSOFA vital sign criteria are a respiratory rate of ≥<NUM> breaths/min, systolic arterial blood pressure of less than or equal to <NUM>/mmHg, and an altered mental status (Glasgow Coma Scale score below <NUM>). It has been determined that patients with a qSOFA score of at least <NUM> have a <NUM>% in-hospital mortality rate, and <NUM>% for patients with a qSOFA score of less than <NUM>. Typically, if the qSOFA score is of at least <NUM>, then the patent will be evaluated with the full SOFA test. The SOFA test is scored on a scale of <NUM>-<NUM> and involves evaluating specific organ systems (respiratory, cardiovascular, liver, renal, coagulation, and central nervous system). If the SOFA score is also greater than or equal to <NUM>, then the patient is considered septic.

Though not initially meant to be a replacement for SIRS, but rather an early detection method, the use of qSOFA has been an improvement over SIRS criteria in general. SIRS, developed in <NUM>, has a high sensitivity, but with very low specificity. SIRS criteria, which may also be referred to as SIRS vital sign criteria or SIRS vital sign measurement, are: a temperature greater than <NUM> degrees C (fever), or less than <NUM> degrees C (hypothermia), a heart rate greater than <NUM> beats/minute (tachycardia), a respiratory rate greater than <NUM> breaths/min (tachypnea), and a WBC less than <NUM>,<NUM> per microliter of blood (<NUM>,<NUM> /mm<NUM>) (leukopenia) or greater than <NUM>,<NUM>/mm<NUM> (leukocytosis). Previous studies have shown that nearly <NUM>% of patients presenting to the emergency department (ED) with suspected infection were shown to have at least <NUM> SIRS points, but very few had severe organ dysfunction. Similarly, other studies have reported that <NUM> to <NUM>% of patients admitted in the ICU, in general, had at least two elements of SIRS. This indicates that having two or more elements of SIRS does not discriminate well enough for organ dysfunction. This is considered to be widely due to the fact that changes in temperature, heart rate, respiratory rate or WBC are typical body responses to many infections and illnesses, not necessarily a life-threatening organ failure or dysregulated body response. Despite this high sensitivity, <NUM> in <NUM> septic patients still does not test positively for sepsis with SIRS criteria.

While qSOFA may be an improvement over SIRS criteria, the American Medical Association (AMA) has noted that there are still considerable drawbacks. The qSOFA was developed for patients already suspected of having an infection, meaning that it is not meant to be an alert which can itself discern between patients with or without an infection but, rather, was defined to identify patients most likely to die. The qSOFA score has poor sensitivity for early sepsis indication but, rather, serves to identify patients who are among the most ill and with higher mortality risk. Second, altered mental status, which may also be referred to as AMS or sepsis-associated delirium (SAD), is a subjective measurement and can vary clinically. Finally, qSOFA does not include any blood measurements that have previously been shown to be effective for screening sepsis, such as WBC.

The present disclosure relates to methods for detecting an infection, including infections resulting in sepsis, by using vital signs combined with parameters measured by a hematology analyzer. Measuring systolic blood pressure (SBP), a vital sign, has been found to improve sepsis prediction accuracy, especially when combined with parameters measured by a hematology analyzer. When combined with abnormal MDW and WBC, other qSOFA or SIRS vital sign measurements have also been found to improve sepsis detection, including altered mental status, temperature, heart rate, respiratory rate, and combinations of these criteria, such as heart rate together with respiratory rate. Furthermore, the benefit of these methods has been observed using only the vital sign measurements collected in the early stages of patient triage, beginning within the first hours of presentation. This includes measurements taken in any of the first <NUM>-<NUM> hours of presentation. Further benefit may be attained by including measurements made beyond the first <NUM> hours of presentation. Patient presentation may be to any medical setting including hospital ED, emergency vehicle, critical care center, in-patient care facility, out-patient care facility, hospice home, specialty clinic, long-term patient care facility, senior home, rehabilitation center, urgent care, telehealth, or specialty treatment center, for example.

<FIG> schematically depicts an embodiment of an infection detection method <NUM> according to the present disclosure. In this embodiment, a patient's vital signs may be measured and recorded in EMR <NUM>, and a blood sample obtained <NUM>. This blood sample may then be processed by a hematology analyzer <NUM>. Vital sign and blood sample measurements may be input into a laboratory information system (LIS) for processing either manually or automatically <NUM>. These measurements may be obtained by the LIS from a patient record, such as an electronic medical record (EMR) or from a laboratory instrument, otherwise referred to as analyzer. These measurements may be obtained during early patient triage. Early patient triage may be defined by the first measurement of a patient's vital signs by a trained professional and may include the first <NUM>-<NUM> hours of patient presentation. Patient presentation occurs on arrival of a patient to a medical setting and may be marked by the time in which a patient has been registered clerically or, in emergency situations, the time in which a patient is triaged. Patient presentation may also refer to the moment a patient is introduced to a trained professional in a medical setting. A medical setting may include a hospital ED, emergency vehicle, critical care center, in-patient care facility, out-patient care facility, hospice home, specialty clinic, long-term patient care facility, senior home, rehabilitation center, urgent care, telehealth, or specialty treatment center. A trained professional may include physicians, nurses, therapists, physician assistants, hospice workers, emergency medical technicians, and any other trained caregivers. In the examples disclosed herein, the first measurement of vital signs by a trained professional was, on average, executed within <NUM> hours after introduction to a nurse in the ED. The blood sample measurements may include WBC and MDW. The vital sign measurements may include any SIRS or qSOFA vital sign measurement. The vital sign measurements may include a blood pressure measurement. In some aspects, the LIS includes a processor and a non-transitory computer readable storage medium. The computer readable medium may be programmed with an application to cause the processor to evaluate inputted measurements to determine whether each measurement meets a predetermined criterion, based on an algorithm <NUM>. Based on which of the predetermined criteria is met for the inputted measurements, the probability that a patient will develop sepsis may be determined <NUM>. The predetermined criteria for these measurements may be a range of values considered to be abnormal for a healthy adult, and predictive of developing sepsis alone or in combination with other measurements.

As stated, these measurements may be extracted from an EMR by a LIS. An EMR is a real-time, comprehensive collection of patent data including medical history, physician notes, diagnoses, medication, allergies, immunizations, laboratory test results and vital signs. A LIS is a software system that stores, processes, and manages laboratory analyzer data, and patient information, including patient sample measurements. Laboratory test results derived from a patient biological sample, such as WBC and MDW, may also be input to the LIS manually, by a laboratory professional, or directly from an analyzer. An analyzer is a clinical diagnostic machine capable of measuring one or more anatomical or physiological properties of a sample, including: metabolic measurements (also referred to as blood chemistry); cell counts; viral protein, viral gene or microbial cell measurements; urine measurements; genomic characterizations; or immunological measurements. <FIG> schematically depicts an exemplary hematology analyzer process <NUM>. In this embodiment, a patient's blood sample may be delivered to the analyzer <NUM>, at which point the analyzer may prepare the sample for analysis. Once the sample preparation is concluded <NUM>, the sample may pass through a conductivity module <NUM> and light scatter module <NUM>. Sample measurements may then be evaluated by a data processing module <NUM> and, once complete, measurements may be displayed by a reporting module <NUM>.

As stated, embodiments of the present disclosure may improve the predictive ability of MDW through combination with WBC and vital signs. This is accomplished by evaluating these measurements against predetermined criteria, which may be a range of values considered to be abnormal for a healthy adult. In some aspects, an abnormal WBC count may be equal to the SIRS criteria of a value less than <NUM>,<NUM>/mm<NUM> (<NUM>. 0x10<NUM>/µL) or greater than <NUM>,<NUM>/mm<NUM> (<NUM>. 0x10<NUM>/µL). In some aspects, an abnormal WBC count may be equal to the medical definition of a value less than about <NUM>,<NUM>/mm<NUM> and greater than about <NUM>,<NUM>/mm<NUM>. In some aspects, an abnormal MDW may be a value greater than <NUM> channels. In some aspects, an abnormal SBP may be a value less than or equal to <NUM> mmHg. Notably, this differs from the standard medical definition of hypotension, which is a value of or below <NUM> mmHg. One of skill in the art understands that these cutoffs can be modified to address, for example, specific patient sub-populations (such as cancer patients, pediatric patients, etc.) or to modify the sensitivity and/or specificity of the test (e.g., by opening a range to make it more inclusive, or further limiting a range to make it more exclusive).

In a hospital setting, there are four measurements, referred to as vital signs, which are routinely monitored by medical professionals. Vital signs are typically recorded during any hospital visit, but especially during ED triage, which is used to identify a patient's level of urgency and treatment pathway. These measurements are body temperature, pulse rate, respiration rate, and blood pressure. Body temperature can be measured in several different ways including orally, rectally, axillary (under the arm), by ear, or by skin. A normal body temperature for a healthy adult, though highly variable with respect to conditional information such as measurement method, location, or time of day and is considered to be any temperature within a range from <NUM> degrees Fahrenheit to <NUM> degrees Fahrenheit, with an average value of <NUM> degrees Fahrenheit. A higher than normal body temperature is called hyperthermia, or fever, and a lower than normal body temperature is called hypothermia.

"Pulse rate," or "heart rate," is a measurement of the number of times the heart beats in a minute. This can be measured by various machines or by manually pressing one's fingertips to either a patient's neck or wrist and counting the number of beats per unit time. A normal pulse rate for a healthy adult ranges from <NUM> to <NUM> beats per minute.

Respiration rate is the number of breaths one takes in one minute. This measurement can be taken by counting the number of breaths a patient takes per unit time. A normal respiration rate for a healthy adult is between <NUM> and <NUM> breaths per minute.

Blood pressure is a measurement of the pressure resulting from blood pressing against the walls of one's arteries. It is recorded as two numbers, often in millimeters of mercury (mmHg). The first number is typically systolic pressure, the pressure in the arteries resulting from the heart contracting and pushing blood into the arteries. The second number is typically diastolic pressure, the pressure in the arteries when the heart relaxes and is refilled with blood between contractions. Blood pressure can be approximated through noninvasive measurement using an instrument called a sphygmomanometer, where an inflatable cuff is placed around one's arm. The cuff inflates until the circulation in the patient's arm is reduced. At this point, the air is slowly released and the person measuring the blood pressure will listen for blood moving through the patient's artery with a stethoscope. The first sound that is heard corresponds to the systolic blood pressure (SBP), and the point that this sound goes away corresponds with the diastolic blood pressure. Blood pressure can also be measured noninvasively by other means, including automated machines. A more accurate determination of blood pressure can be obtained invasively through catheter measuring devices which may be inserted into various parts of the cardiovascular system. The average blood pressure measurement for a healthy adult is considered to be <NUM>/<NUM> mmHg. Low blood pressure ("hypotension") is a reading of <NUM>/<NUM> mmHg or lower. High blood pressure ("hypertension") is a reading of <NUM>/<NUM> mmHg or higher.

Other vital signs are also recognized in the medical field including: pain, measured on a <NUM> to <NUM> pain scale, oxygen saturation, measured by pulse oximetry, blood glucose level, measured in mmol/L, menstrual cycle indications, such as length and regularity, end-tidal CO<NUM> (ETCO<NUM>), measured in percentage of CO<NUM> or mmHg, walking speed, measured in meters/second, altered mental status, or delirium, which may be measured by several different rating scales including the Glasgow Coma Scale (GCS), which ranges from a score of <NUM> to <NUM>.

For the calculation of qSOFA, altered mental status is measured by the GCS, a scoring system used to assess a patient's level of consciousness. The GCS is measured on a <NUM>-point scale based on eye, verbal, and motor criteria where a lower score is associated with the most severe brain dysfunction. The eye response is scored from <NUM>-<NUM>, where no eye opening is given a score of <NUM> and spontaneous eye response is given a score of <NUM>. Verbal response is measured from <NUM>-<NUM>, no verbal response (<NUM>) to an oriented verbal response (<NUM>). Motor response is measured from <NUM>-<NUM>, no motor response (<NUM>) to obeys command (<NUM>). A GCS score of <NUM> points or less is associated with severe brain dysfunction or injury, a GCS score of <NUM> to <NUM> is associated with moderate brain dysfunction or injury, and a GCS score of <NUM> to <NUM> is associated with mild brain dysfunction or injury, and a score of <NUM> is considered normal. The qSOFA criteria for altered mental status includes any GCS score below <NUM>.

"Patient" can refer to any individual currently receiving medical care, a person in need of medical care, a person waiting to receive medical care, or a person who has already received medical care. "Patient" does not necessarily mean that the individual is suffering from any condition and can include individuals receiving routine health examinations. Patient refers to individuals in a hospital setting, in long term care facilities, nursing homes, emergency vehicles, in-home care settings, urgent care facilities and anywhere else that a person may receive medical attention from a trained professional. A trained professional may include physicians, nurses, therapists, physician assistants, hospice workers, emergency medical technicians, and any other trained caregivers. Patients hospitalized for less than <NUM> hours may also be referred to as "outpatients," while those staying at a hospital for more than <NUM> hours may be referred to as "inpatients.

Patient information is typically stored in a patient medical record, or EMR (also referred to as EHR). This information can include SIRS measurements, qSOFA measurements, and vital signs recorded during ED triage. The EMR may collect this information directly from a medical device, or measurements may be manually entered into the EMR by a medical professional.

WBC is a test that measures the number of white blood cells, also called leukocytes, in a patient's body. These cells are important for fighting infections in a body, and an increased WBC number can indicate infection or other underlying conditions in the body, in some instances before a patient presents clinical symptoms or when a patient presents ambiguous clinical symptoms. A normal WBC count for a healthy adult can vary between about <NUM>,<NUM> to <NUM>,<NUM> white blood cells per microliter (µl or mcL) or cubic millimeter (mm<NUM>) of blood. This is different from the normal count defined by SIRS criteria (<NUM>,<NUM> to <NUM>,<NUM> WBC/mcL).

Sub-types of white blood cells may be measured as a differential (CBC-diff), with each sub-type being within a typical percentage of the total WBC: neutrophil (<NUM> to <NUM> percent), lymphocyte (<NUM> to <NUM> percent), eosinophil (<NUM> to <NUM> percent), monocyte (<NUM> to <NUM> percent), and basophil (<NUM> to <NUM> percent).

Measuring a patient's WBC can require a blood draw, otherwise known as a venipuncture. This procedure, often performed by a phlebotomist, involves the insertion of a small needle into a patient's vein and collecting blood into a <NUM> to <NUM> tube. This blood tube may then be transferred to an automated machine that will analyze the sample to determine the number of white blood cells, an embodiment of which is depicted in <FIG>. In an automated embodiment, in addition to the percentage of each white blood cell type, it is possible to obtain detailed morphological information about the blood cells, such as volume and size. This automated measurement may be based on the direct current (DC) impedance measured from cells in a blood sample. This traditional method, also known as the Coulter Principle, is accomplished by an analyzer through passing an electric current through a blood sample and measuring the number of individual cells based on a change in impedance resulting from the cells passing through a measurement module. Another automated method is a laser flow cytometry system which transmits light through a blood sample. One or more absorption signals are measured, and the resulting light scatter is measured at different angles to determine cell morphology. Another method is fluorescent flow cytometry, which works like flow cytometry but, with the addition of fluorescent reagents, has an extended capability of measuring more specific cell populations and more specific morphological information, such the nucleus-to-plasma ratio of certain cells. Imaging is another method and involves a camera which automatically collects images of stained cells and can use image processing and pattern-recognition techniques to classify the cells automatically or present detailed cell images to a professional for review. Cell count and morphology information may also be measured manually, by a medical professional, by transferring a blood sample to a microscope slide, staining the slide, and making a visual morphology evaluation and cell count. This process involves placing a drop of blood onto a slide and using a "spreader slide" to disperse the blood across the slide so that the blood cells are sufficiently far apart to be manually differentiated. Once the blood, also referred to as blood film, is fixed to the slide, typically through immersion in methanol, it may be stained. Routine blood analysis is typically performed on blood films stained with Romanowsky stains, which allow for the detection of cell types and morphology.

MDW is the standard deviation of monocyte volume. A monocyte is a type of white blood cell. The monocyte volume measurement may be determined by passing an electric current through a blood sample and measuring the volume of individual cells passing through a measurement module based on measuring the amplitude of the resulting impedance measurement. This volume may also be measured by a system which transmits light through a blood sample and measures the resulting light scatter to determine cell volume. Methods to detect the presence of sepsis and/or SIRS using WBC population data, including MDW, have been described, for example, in <CIT>; PCT Application No. <CIT>; and <NPL>.

Analyzer information can be stored directly on an analyzer's software system or collected by a LIS. A LIS is a software-based laboratory information management system and is involved with inputting, processing, and storing a variety of information from analyzers throughout the lab as well as patient information. This includes the processing and storage of patient sample measurements, such as MDW or WBC. A LIS may also gather patient information from an EMR, such as vital sign measurements as well as completed patient sample measurements from an analyzer. This information may be combined with the information in the LIS and analyzed by the software to make disease state predictions. This analysis may be executed by evaluating whether selected measurements meet a predetermined criterion. Based on which predetermined criteria is met for the inputted measurements, the probability that a patient will develop sepsis may be determined. A prediction report or alert may be sent to a medical professional so that they may decide how to best treat a patient.

Embodiments of the present disclosure were tested on <NUM> adult subjects aged <NUM>-<NUM> years old who had a CBC with differential test ordered upon presentation to the ED, SIRS and qSOFA criteria tested, and remained in the hospital for at least <NUM> hours. Vital sign and blood measurements associated with these patients were made during early ED triage, within the first <NUM> hours of presentation. Table <NUM> shows the test values observed, and the predetermined ranges that were used to evaluate whether a patient's measurements were normal or abnormal. The WBC data was obtained from a SIRS test, and the normal range referred to herein is consistent with the SIRS criteria definition.

Table 2A shows the positive likelihood ratio (LR+) and post-test sepsis probability based on whether MDW and WBC values were within a predetermined range. Likelihood ratios are used in diagnostic testing to assess the value of performing a given test. LR+ evaluates the ratio of sensitivity versus specificity (sensitivity/<NUM>-specificity), and the result indicates the probability that the test result is correct. For further definition, sensitivity is the ratio of TP versus the total of combined TP and false negative (FN) results (TP/TP+FN). Specificity is the ratio of true negative results (TN) vs the total of combined TN and FP results (TN/TN+FP).

LR scores range from zero to infinity. The higher the score, the more likely it is that a person has a condition. A value equal to <NUM> would indicate a patient is <NUM> times more likely that the patient has a condition than not. Values from <NUM> to <NUM> have decreased evidence for the disease, meaning, the closer to zero the more unlikely it is that the patient has the given condition. A value equal to <NUM> has no diagnostic value. Clinically, values between <NUM> and <NUM> indicate a minimal increase of disease likelihood, values between <NUM> and <NUM> indicates a small increase of disease likelihood, values between <NUM> and <NUM> signify a moderate increase in disease likelihood, and values greater than <NUM> signify a large, and often conclusive, increase in disease likelihood.

Table 2A shows that a patient with both normal WBC and MDW are unlikely to have sepsis, which is supported by a low LR+ and a post-test probability of <NUM>%. In this example, the initial (pre-test) sepsis prevalence, as determined by the embodiments of the present disclosure, was <NUM>%. By evaluating MDW and WBC together, this test provided a sepsis probability evaluation of <NUM>%, and a LR+ of <NUM> if a patient expressed abnormal MDW and WBC values. Table 2B shows detailed results, including LR+ confidence intervals.

Table 3A shows the diagnostic statistics when evaluating SBP in addition to MDW and WBC. With the inclusion of abnormal SBP (≤<NUM> mmHg), the post-test sepsis probability increased to <NUM>% and the LR+ increased <NUM>, signifying a large and often conclusive increase in disease likelihood. Combining abnormal SBP and WBC measurements was also an improvement over combining abnormal WBC and MDW alone. In this case, there was an increase in post-test probability from <NUM>% to <NUM>% and, while both LR+ scores signified a moderate increase in disease likelihood, there was an increase from <NUM> to <NUM>. Table 3B shows detailed results, including LR+ confidence intervals.

Table 4A shows the results when other normal SIRS criteria were incorporated. With MDW and WBC alone, and all SIRS criteria being normal, the post-test sepsis probability prediction was <NUM>%, with an LR+ of <NUM>. An LR+ score between <NUM> and <NUM> is recognized as a minimal increase in disease likelihood. In this scenario, even while accounting for other SIRS criteria being in the normal healthy range, an abnormal SBP value combined with abnormal MDW and WBC resulted in a post-test sepsis probability evaluation of <NUM>% and an LR+ of <NUM>, signifying a moderate increase in disease likelihood. Table 4B shows detailed results, including LR+ confidence intervals.

Improvements to sepsis probability assessments were also observed when incorporating other vital sign measurements with MDW. Table <NUM> shows the finding that the odds of sepsis diagnosis, as defined by Sepsis-<NUM>, increase by <NUM> times when an abnormal MDW, is combined various qSOFA parameters, in comparison to a normal MDW. In this scenario, sepsis was defined by Sepsis-<NUM> criteria as qSOFA was developed for the Sepsis-<NUM> definition.

Table <NUM> shows the finding that the odds of sepsis-<NUM> diagnosis increase by <NUM> times when an abnormal MDW, in comparison to normal MDW, is combined with any number of SIRS criteria. In this scenario, sepsis was defined by Sepsis-<NUM> criteria as SIRS was developed for the Sepsis-<NUM> definition.

<FIG> further show how improvements in sepsis detection are also observed when MDW and WBC are used in combination with specific SIRS vital sign criteria. MDW and WBC improves early sepsis detection when combined with abnormal vital signs of tachycardia (<FIG>), tachypnea (<FIG>), both tachycardia and tachypnea (<FIG>), or abnormal temperature (<FIG>). The highest probability of sepsis occurs when there is a combination of abnormal MDW, abnormal WBC, and one or more abnormal (SIRS) vital signs criterion.

<FIG> exemplify that MDW and WBC in combination with the qSOFA vital sign criteria of altered mental status (<FIG>) and blood pressure (<FIG>), also markedly improves sepsis detection. In these scenarios, the highest probability of sepsis occurs when both MDW and WBC are also abnormal.

<FIG> shows the finding that MDW actually improves detection of sepsis in ED patients across a range of WBC values, including when WBC is normal. The shaded areas in this figure indicate abnormal WBC measurements.

These scenarios exemplify the added value of incorporating SBP measurements and other vital sign measurements with WBC and MDW.

Claim 1:
A method of assessing a probability that a patient will develop sepsis comprising:
a. at a data processing system, receiving measurements comprising a white blood cell count (WBC), a monocyte distribution width (MDW), and one or more vital signs wherein the one or more vital signs comprises systolic blood pressure (SBP), and
b. the data processing system processing the received measurements to (i) determine whether each measurement meets a corresponding predetermined criteria and (ii) assign the probability that the patient will develop sepsis.