title: Casting a Wider Net: Data Driven Discovery of Proxies for Target Diagnoses.
abstract: The Hospital Readmissions Reduction Program (HRRP) introduced in October 2012 as part of the Affordable Care Act (ACA), ties hospital reimbursement rates to adjusted 30-day readmissions and mortality performance for a small set of target diagnoses. There is growing concern and emerging evidence that use of a small set of target diagnoses to establish reimbursement rates can lead to unstable results that are susceptible to manipulation (gaming) by hospitals.
  
  
  
  We propose a novel approach to identifying co-occurring diagnoses and procedures that can themselves serve as a proxy indicator of the target diagnosis. The proposed approach constructs a Markov Blanket that allows a high level of performance, in terms of predictive accuracy and scalability, along with interpretability of obtained results. In order to scale to a large number of co-occuring diagnoses (features) and hospital discharge records (samples), our approach begins with Google's PageRank algorithm and exploits the stability of obtained results to rank the contribution of each diagnosis/procedure in terms of presence in a Markov Blanket for outcome prediction.
  
  
  
  Presence of target diagnoses acute myocardial infarction (AMI), congestive heart failure (CHF), pneumonia (PN), and Sepsis in hospital discharge records for Medicare and Medicaid patients in California and New York state hospitals (2009-2011), were predicted using models trained on a subset of California state hospitals (2003-2008). Using repeated holdout evaluation, we used ~30,000,000 hospital discharge records and analyzed the stability of the proposed approach. Model performance was measured using the Area Under the ROC Curve (AUC) metric, and importance and contribution of single features to the final result. The results varied from AUC=0.68 (with SE<1e-4) for PN on cross validation datasets to AUC=0.94, with (SE<1e-7) for Sepsis on California hospitals (2009 - 2011), while the stability of features was consistently better with more training data for each target diagnosis. Prediction accuracy for considered target diagnoses approaches or exceeds accuracy estimates for discharge record data.
  
  
  
  This paper presents a novel approach to identifying a small subset of relevant diagnoses and procedures that approximate the Markov Blanket for target diagnoses. Accuracy and interpretability of results demonstrate the potential of our approach.
authors.affiliation: Center for Data Analytics and Biomedical Informatics, Temple University, Philadelphia, PA, USA.
authors.forename: Dusan
authors.initials: D
authors.lastname: Ramljak
authors.affiliation: Center for Data Analytics and Biomedical Informatics, Temple University, Philadelphia, PA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Davey
authors.affiliation: Center for Data Analytics and Biomedical Informatics, Temple University, Philadelphia, PA, USA.
authors.forename: Alexey
authors.initials: A
authors.lastname: Uversky
authors.affiliation: Center for Data Analytics and Biomedical Informatics, Temple University, Philadelphia, PA, USA.
authors.forename: Shoumik
authors.initials: S
authors.lastname: Roychoudhury
authors.affiliation: Center for Data Analytics and Biomedical Informatics, Temple University, Philadelphia, PA, USA.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Obradovic
mesh_terms: D000368:Aged; D002140:California; D015897:Comorbidity; D003933:Diagnosis; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology; D009518:New York; D058991:Patient Protection and Affordable Care Act; D010359:Patient Readmission; D011014:Pneumonia / Q000175:diagnosis / Q000453:epidemiology; D018805:Sepsis / Q000175:diagnosis / Q000453:epidemiology; D014481:United States