Abstract:
A computerized system and method comprises a predictive model for estimating the probability of a patient hospital readmission. The computerized system and method is useful for identifying patients at risk of hospital readmission and further identifying an intervention to mitigate the risk and reduce the likelihood that the patient returns to the hospital. The computerized system method collects and analyzes historical health data from administrative claims data and current health data collected in real-time from medical records at the point of treatment. Signals indicating readmission are extracted from the health data that is collected. The signals are evaluated by the model software application to estimate a probability that a patient will be readmitted to the hospital. Patients with a high readmissions probability score are selected for clinical programs and interventions that help them manage their health conditions and problems and reduce the likelihood that they return to the hospital.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to US Provisional Patent Application Ser. No. 61/428,101, filed Dec. 29, 2010, titled COMPUTERIZED SYSTEM AND METHOD FOR REDUCING HOSPITAL READMISSIONS, the content of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Unplanned and preventable hospital readmissions (also called rehospitalizations) represent an increasing share of healthcare costs. In response to the rising cost, a number of healthcare providers and payors have undertaken studies to determine more accurate estimates of the cost. One health benefits provider, Humana Inc., recently estimated its total cost for hospital readmissions in 2009 at over $600M. The 2009 average allowed cost per readmission for the health benefits provider was further estimated to be $10,328. Other studies estimate aggregate total annual costs for readmissions/rehospitalizations to be tens of billions of dollars. 
         [0003]    At least one study estimates that three-quarters of Medicare patient readmissions could likely be avoided with better care 1 , thereby resulting in substantial savings. Even a small decline in hospital readmission rates can result in a substantial healthcare cost savings. Reducing admissions, however, requires an understanding of why they occur and who is at risk. Current efforts directed toward reducing readmissions include collecting data at the point of treatment and applying empirical clinical rule sets to identify patients at risk for readmission. The rule sets are typically developed by clinical personnel and reflect their judgment of risk factors associated with readmission. Although a rule-based approach facilitates the process of identifying at risk patients, it is, unfortunately, fairly inaccurate. The rules are based primarily on personal judgment from clinical personnel and therefore, subjective. Different clinicians reach different conclusions when presented with the same set of clinical facts. In addition, the rules-based model does not support good risk stratification. The outcome of the process is the identification of a patient that is “at risk” or “not at risk.” The outcome reflects the presence of a risk rather than the quantification of a risk. Finally, because the rules are developed and applied by clinical personnel, only a limited number of factors or data elements can practicably be considered in each case.  1  Report to the Congress: Promoting Greater Efficiency in Medicare, Medicare Payment Advisory Commission, Jun. 2007: 111-114. 
         [0004]    Reducing readmissions and rehospitalizations requires not only identifying contributory risk factors to identify at-risk patients, but also providing patients with information and/or directing them to interventions or programs that focus on mitigating the contributory factors. The identification and mitigation of risk factors not only assists healthcare providers and payors in reducing costs but also contributes to patient well-being and better outcomes. By addressing the contributory risk factors after hospitalization, patients focus on improving various aspects of their health conditions and may avoid subsequent admissions to the hospital. 
         [0005]    Patients, as well as healthcare providers and payors, benefit from a reduction in hospital readmissions. The identification of risk factors allows providers, payors, and patients to apply resources in a manner that reduces the likelihood a patient will return to the hospital. There is a need for a system and method that accurately and objectively identifies patients at risk for hospital readmission. There is a need for a system and method that identifies the patients with a high probability of readmission and further, directs them to the appropriate clinical intervention or program or provides them with information and other assistance to help them avoid further hospitalizations. There is a need for a system and method that benefits patients, healthcare providers, and healthcare payors by reducing hospital readmissions. 
       SUMMARY OF THE INVENTION 
       [0006]    A computerized system and method according to the present disclosure comprises a predictive model for estimating the probability of a patient&#39;s hospital readmission. In an example embodiment, the computerized system and method estimates the probability of readmission within 30 days for each initial admission. The computerized system and method is useful for identifying patients at risk of hospital readmission and further identifying an intervention to mitigate the risk and reduce the likelihood that the patient returns to the hospital. The identification of risk factors may be used to drive patients to the appropriate intervention, at an appropriate time, and in an appropriate way. 
         [0007]    The computerized system and method may be used by a healthcare payor such as a health benefits provider. A predictive model is developed and integrated in a model software application that receives patient data as input and predicts for the patient the likelihood of a readmission or rehospitalization. The computerized system method collects and analyzes: (a) historical health data from administrative claims data; and (b) current health data collected in real-time from medical records at the point of treatment. Signals indicating readmission are extracted from the health data that is collected. The signals are evaluated by the model software application to estimate a probability that a patient will be readmitted to the hospital within a particular period of time (e.g., 30 days). 
         [0008]    Patients with a high readmissions probability or risk score are selected for clinical programs and interventions that help them manage their health conditions and problems and reduce the likelihood of returning to the hospital. The clinical programs and interventions may include educating patients about their health conditions and providing specific recommendations related to monitoring their health status, medications, follow-up visits with healthcare providers, preventive and maintenance care, etc. Patient compliance with intervention efforts may be monitored to identify those patients that are at greatest risk for rehospitalization. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a block diagram illustrating development and application of a hospital readmission predictive model and model application according to an example embodiment; 
           [0010]      FIG. 2  is a diagrammatic representation of data complexities for a hospital readmissions predictive model according to an example embodiment; 
           [0011]      FIG. 3  is a block diagram illustrating development details of a predictive model according to an example embodiment; 
           [0012]      FIG. 4  is a diagram of variables considered and associated probability of readmission according to an example embodiment; 
           [0013]      FIG. 5  is a comparison of actual to predicted readmission rates according to an example embodiment; and 
           [0014]      FIGS. 6A and 6B  are block diagrams of a readmissions predictive model system according to example embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    In an example embodiment a predictive model for hospital readmissions is integrated in a model software application for use by a health benefits provider with a covered patient-member population. Referring to  FIG. 1 , a block diagram illustrating development and application of a hospital readmission predictive model and model application according to an example embodiment is shown. Historical clinical data such as administrative claims data for medical and/or pharmacy claims and clinical/health program participation data as well as consumer data such as contact data, demographic data, and financial data  100  is input to a predictive model. The data may be cleansed  102  and mined  104  according to various well-known techniques. A hospital readmission predictive model  106  is developed using various well-known techniques as listed in Table 1. 
         [0000]    
       
         
               
             
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Predictive Model Techniques 
               
             
          
           
               
                 Modeling 
                   
               
               
                 Technique 
                 Description 
               
               
                   
               
               
                 Decision 
                 Mapping of observations based on decisions to predict 
               
               
                 Tree 
                 value of a variable. 
               
               
                 Regression 
                 Estimates linear dependence of one or more independent 
               
               
                   
                 variables on a dependent variable. 
               
               
                 Neural 
                 Nonlinear technique for modeling complex functions. 
               
               
                 Networks 
               
               
                 Ensemble 
                 Combination of multiple models for consensus prediction. 
               
               
                   
               
             
          
         
       
     
         [0016]    The predictive model is then incorporated into a model application  108  that is applied to a member population. Members of the population that are at risk for readmission are selected for proactive clinical interventions and programs  110 . The use of the model with proactive clinical programs and interventions helps to improve outcomes for members  112  and to reduce hospital-related costs for the health benefits provider  114 . 
         [0017]    Referring to  FIG. 2 , a diagrammatic representation of data complexities for a hospital readmissions predictive model according to an example embodiment is shown. As indicated in  FIG. 2 , various factors may increase the likelihood that a member  200  is readmitted or rehospitalized. The likelihood of readmission may be expressed as a score  218  assigned to a member in relation to various factors such as: clinical diagnosis  202 ; age  204 ; gender  206 ; previous admissions  208  (e.g., any prior admissions, number of previous admissions, days since last admission); medications and surgery  210 ; length of stay  212 ; bed type  214 ; and comorbidities  216 . Although many factors may contribute to a patient&#39;s readmission, some factors may be better “predictors” than others and therefore, incorporated into the model application applied to the member population. 
         [0018]      FIG. 2  further illustrates the elements of administrative claims data and current treatment data that may be relevant to a patient&#39;s readmission score. For example, diagnosis  202 , age  204 , gender  206 , number of previous admissions  208 , days from last admission  208 , and comorbidity  216  data may be discerned from member profile and administrative claims data while medication/surgery  210 , length of stay  212 , and bed type  214  may be discerned from a current medical record or treatment data. One of skill in the art would recognize that relevant input may be obtained from various databases and sources and may be provided to a readmissions predictive model as described herein. 
         [0019]    Referring to  FIG. 3 , a block diagram illustrating development details of a predictive model according to an example embodiment is shown. As illustrated in  FIG. 3 , membership and medical/pharmacy claims data for a covered population may be used as input to a predictive modeling system. The use of claims data provides the predictive modeling system with multiple years of data experience for millions of lives. Additionally, the input data may comprise medical records and other related demographic and financial data for the covered population. In the example shown, Medicare claims data for members discharged from a hospital and returned to a home or home healthcare setting is analyzed. One record for each initial admission may be analyzed. The model generates data of hospital readmissions and a variety of potential signals of readmissions from the database. 
         [0020]    In the example shown, 417,638 original admissions were considered  300 . A random sample of 70% of the entire data table was used to build and tune the model and 30% of the data table was used to test the model. For the Medicare population, 40% of all initial admissions were randomly assigned to the training dataset  302  and 30% to the validating (tuning) dataset  304 . The model was built on the training dataset and subsequently validated. The model was then executed on the remaining 30% of the data (testing dataset  306 ) to assess the model&#39;s performance. 
         [0021]    The predictive modeling system identifies and captures statistical relationships between potential signals and readmissions. Referring to  FIG. 4 , a diagram of variables considered and associated probability of readmission according to an example embodiment are shown. The Chi Square value shown in  FIG. 4  is a statistical measure representing the relationship between the variables. As shown in  FIG. 4 , the three strongest predictors of a hospital readmission are “days between previous and current admission,” the Charlson Comorbidity Index, and “admission count in past six months.” Details of the numbers associated with the top three predictors are shown in Tables 2, 3, and 4. 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Days Between Previous and Current Admissions 
               
             
          
           
               
                 Days 
                 Total 
                 Readmission 
                 Readmit Rate 
               
               
                   
               
             
          
           
               
                  0-30 
                 63,338 
                 19,156 
                 28.03% 
               
               
                 31-60 
                 26,365 
                 6,380 
                 24.20% 
               
               
                 61-90 
                 17,458 
                 3,655 
                 20.94% 
               
               
                  91-180 
                 31,781 
                 5,799 
                 18.25% 
               
               
                 181-365 
                 29,991 
                 4,681 
                 15.61% 
               
               
                 No Previous Admit 
                 243,705 
                 27,784 
                 11.40% 
               
               
                 Total 
                 417,638 
                 67,455 
                 16.15% 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Charlson Comorbidity Index 
               
             
          
           
               
                 Comorbidity Rate 
                 Total 
                 Readmission 
                 Readmit Rate 
               
               
                   
               
             
          
           
               
                 0-5 
                 252,811 
                 28,913 
                 11.44% 
               
               
                  6-10 
                 134,474 
                 28,783 
                 21.40% 
               
               
                 11-15 
                 26,892 
                 8,419 
                 31.31% 
               
               
                 16+ 
                 3,461 
                 1,340 
                 38.72% 
               
               
                 Total 
                 417,638 
                 67,455 
                 16.15% 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 Admit Count in Past Six Months 
               
             
          
           
               
                   
                 Admit Count 
                 Total 
                 Readmission 
                 Readmit Rate 
               
               
                   
                   
               
             
          
           
               
                   
                 0 
                 272,216 
                 32,315 
                 11.87% 
               
               
                   
                 1 
                 89,136 
                 16,946 
                 19.01% 
               
               
                   
                 2 
                 32,149 
                 8,646 
                 26.89% 
               
               
                   
                 3 
                 13,266 
                 4,517 
                 34.05% 
               
               
                   
                 4 
                 5,807 
                 2,353 
                 40.52% 
               
               
                   
                 5 
                 2,697 
                 1,279 
                 47.64% 
               
               
                   
                  6+ 
                 2,367 
                 1,399 
                 59.10% 
               
               
                   
                 Total 
                 417,638 
                 67,455 
                 16.15% 
               
               
                   
                   
               
             
          
         
       
     
         [0022]    Referring to  FIG. 5 , a comparison of actual to predicted readmission rates according to an example embodiment is shown.  FIG. 5  illustrates the performance of the predictive model by comparison with actual rates and indicates a strong correlation between the predictive rates and actual rates. 
         [0023]    Referring to  FIG. 6A , a block diagram of a readmissions predictive model system according to an online example embodiment for a health benefits provider is shown. The readmissions predictive model  602  may be integrated in a model software application used in real-time and applied to patient data on demand. In the “online” example embodiment, the model software application executes on a server and receives data from a clinical profile database and/or clinical care advance system  600  in response to a user request. The clinical profile database comprises a complete profile for a covered member including contact information, demographic profile data such as age and gender, claims data for medical and/or pharmacy claims submitted by the member to the health benefits provider, a contact history with details regarding communications between the member and the health benefits provider (e.g., mailings, telephone calls, emails, web site visits, and other outreach efforts), and participation data related to clinical programs and interventions in which the member has been enrolled and/or participated. A clinical care advance system may be used by nurses and clinical specialists to access the member&#39;s clinical profile and claims data and to assist them in providing services to members. Nurses, clinical specialists, and other representatives of the health benefits provider may interact with members to provide information about programs and interventions and other assistance related to the member&#39;s health conditions or problems. 
         [0024]    An admission trigger from the clinical profile data and/or clinical care advance system database  600  may be used to invoke the readmission predictive model  602  and to estimate a readmission probability score for a member. In an example embodiment, the readmission predictive model is triggered by specified events during the admission stay in the hospital such as admission to the hospital, discharge from the hospital, or a major status change such as transfer to an intensive care unit. Data related to these events is entered in a clinical care advanced system database, and triggers the model to make predictions based on the most up-to-date information. 
         [0025]    A customer care representative from the health benefits provider may interact with an online clinical care advance system  604  and may request a readmission score in connection with assisting the member while using the clinical care advance system  604 . The clinical care advance system allows a representative to access the member&#39;s profile data and see details that may assist the representative in providing information and services to the member. 
         [0026]    The model  602  is applied to the member&#39;s clinical profile data  600 , which is refreshed periodically, to generate a readmission score. The score may then be compared against a threshold value  606 . Patients with scores above the threshold may be considered for further action  608  while patients with scores below the threshold are not considered for further action  612 . One of skill in the art would recognize that the score threshold may be established in such a way that a certain percentage of the covered population (e.g., 20%) is selected for further action. One of skill in the art would also recognize that score ranges (e.g., 0-100, 101-250, 251+) may be established, each of which is associated with a different intervention action. In some instances, no additional action or limited action may be taken (e.g., a phone call) as the readmission score is within an acceptable or low risk range. The scores may be used in a variety of ways to determine whether certain members are directed to additional programs and interventions. 
         [0027]    Members with scores that exceed a threshold  606  may be considered for additional clinical programs or interventions. Additional filters  608  may be applied to the member&#39;s profile data to identify appropriate clinical programs or interventions. The programs and/or interventions may be selected based on the member&#39;s health conditions or problems. Members that have been diagnosed with certain diseases or conditions (e.g., asthma, coronary artery disease, depression, diabetes) may be enrolled in a disease management program. Other programs may not be directed to a specific disease or condition but may be available to members to help them with various issues or concerns as they arise (e.g., nurse services, chronic care management, pharmacy counseling and education). Each program or intervention may have associated selection criteria  608  that are applied to member clinical data to determine whether a member is a candidate for a program or intervention. Example programs and interventions are identified in Table 5. 
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 Program Referrals 
               
             
          
           
               
                 Program 
                 Description 
                 Score 
               
               
                   
               
             
          
           
               
                 Personal Nurse 
                 Phone-based service for members; specially- 
                 170 
               
               
                 (PN) 
                 trained nurses provide health education 
               
               
                   
                 and counseling 
               
               
                 Senior 
                 Service for senior members; case managers 
                 180 
               
               
                 Utilization and 
                 work with members to assess needs and 
               
               
                 Case Management 
                 develop goals 
               
               
                 Company Cares 
                 Chronic care management program; service 
                 175 
               
               
                   
                 to coordinate care from multiple providers 
               
               
                 Communication 
                 Service for all members; case managers work 
                 150 
               
               
                 Utilization and 
                 with members to facilitate and increase 
               
               
                 Case Management 
                 communication 
               
               
                 Prescription 
                 Phone-based service for members; 
                 160 
               
               
                 Mentor 
                 pharmacists provide medication safety 
               
               
                   
                 education and counseling 
               
               
                 Transplant 
                 Service to assist members though evaluation, 
                 200 
               
               
                   
                 inpatient stay, and post-operative period 
               
               
                   
               
             
          
         
       
     
         [0028]    Readmission scores may also be used to develop a risk stratification strategy. In a risk stratification strategy, interventions are determined according to score ranges rather than individual scores. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                 Risk Stratification 
               
             
          
           
               
                 Risk Stratification 
                 Score Range 
                 Interventions 
               
               
                   
               
               
                 Very high 
                 &gt;=200 
                 Nurse home visit 
               
               
                 High 
                 &lt;200 and &gt;=180 
                 Nurse call 
               
               
                 Medium 
                 &lt;180 and &gt;=160 
                 Non-clinical specialist call 
               
               
                 Low 
                  &lt;160 
                 Automatic call 
               
               
                   
               
             
          
         
       
     
         [0029]    Following application of filters or selection criteria, members with readmission scores that exceed a threshold may be referred to specific programs and/or interventions  614  that help them manage their health condition or problem and more importantly, help them to avoid a subsequent hospital visit or admission. For example, some members may receive instructions on taking prescribed medications and possibly avoid an adverse drug event that could result in a hospitalization. Other members may be assigned a personal nurse who answers the member&#39;s questions related to various areas of medical care. In many instances, the access to additional information and support related to the member&#39;s health condition or problem reduces the likelihood of another hospital admission. 
         [0030]    Member participation in the recommended interventions or programs may be tracked in the member&#39;s clinical profile. For example, attendance at consultations for a disease management program may be recorded. Each member contact with the health benefits provider may be recorded. For example, participation data for members that are asked to periodically report health status indicators may be tracked. Members that do not report in when expected may be contacted by a representative of the health benefits provider. 
         [0031]    Referring to  FIG. 6B , a block diagram of a readmissions predictive model system according to an offline example embodiment for a health benefits provider is shown. The readmission predictive model  602  operates in the manner described in relation to  FIG. 6A , but is applied to batched data rather than in response to an online request. In the offline embodiment, the clinical profile/clinical care advance system databases  600  and claims/clinical care advance table  604  may be updated daily through batch updates. The readmission predictive model  602  may be applied to member data to identify members at risk that will soon be discharged from the hospital. A threshold score comparison is made  606 , program and/or intervention filter criteria are applied  608 , and a daily referral list is generated  616 . The referral list  616  is generated in connection with member hospital discharges so that, as appropriate, each member may be enrolled in or start participating in a program or intervention as soon as possible after leaving the hospital. Because many readmissions occur within a few weeks or days of a patient&#39;s discharge from the hospital, timely intervention is important in reducing the likelihood of a readmission. The daily referral list  616  allows the health benefits provider to identify members that are leaving the hospital, and high risk candidates for readmission. Appropriate programs and interventions may be defined at the time of discharge so that the likelihood of readmission is reduced. 
         [0032]    The computerized system and method may be used by a healthcare payor such as a health benefits provider to identify the right members of a covered population for the right clinical interventions and programs, and the right time. The computerized system and method supports early, proactive intervention, and therefore, reduces costs and improves outcomes. 
         [0033]    Models are built from large amount of historical and clinical data. The use of comprehensive data, including all relevant data elements and derived signals, provide higher prediction accuracy than prior art systems and methods. The statistical data patterns captured in the model provide objective and unbiased predictions. Furthermore, the model is suitable for risk stratification. The outcome is a number that is representative of a level of risk. The health benefits provider can then determine what actions to take based on each member&#39;s risk level. 
         [0034]    While certain embodiments of the present invention are described in detail above, the scope of the invention is not to be considered limited by such disclosure, and modifications are possible without departing from the spirit of the invention as evidenced by the claims. For example, readmission thresholds and ranges as well as associated actions may be varied and fall within the scope of the claimed invention. Other aspects of the readmission predictive model may be varied and fall within the scope of the claimed invention. One skilled in the art would recognize that such modifications are possible without departing from the scope of the claimed invention.