title: The Impact of Disability and Social Determinants of Health on Condition-Specific Readmissions beyond Medicare Risk Adjustments: A Cohort Study.
abstract: Readmission rates after pneumonia, heart failure, and acute myocardial infarction hospitalizations are risk-adjusted for age, gender, and medical comorbidities and used to penalize hospitals.
  
  
  
  To assess the impact of disability and social determinants of health on condition-specific readmissions beyond current risk adjustment.
  
  
  
  Retrospective cohort study of Medicare patients using 1) linked Health and Retirement Study-Medicare claims data (HRS-CMS) and 2) Healthcare Cost and Utilization Project State Inpatient Databases (Florida, Washington) linked with ZIP Code-level measures from the Census American Community Survey (ACS-HCUP). Multilevel logistic regression models assessed the impact of disability and selected social determinants of health on readmission beyond current risk adjustment.
  
  
  
  Outcomes measured were readmissions ≤30 days after hospitalizations for pneumonia, heart failure, or acute myocardial infarction. HRS-CMS models included disability measures (activities of daily living [ADL] limitations, cognitive impairment, nursing home residence, home healthcare use) and social determinants of health (spouse, children, wealth, Medicaid, race). ACS-HCUP model measures were ZIP Code-percentage of residents ≥65 years of age with ADL difficulty, spouse, income, Medicaid, and patient-level and hospital-level race.
  
  
  
  For pneumonia, ≥3 ADL difficulties (OR 1.61, CI 1.079-2.391) and prior home healthcare needs (OR 1.68, CI 1.204-2.355) increased readmission in HRS-CMS models (N = 1631); ADL difficulties (OR 1.20, CI 1.063-1.352) and 'other' race (OR 1.14, CI 1.001-1.301) increased readmission in ACS-HCUP models (N = 27,297). For heart failure, children (OR 0.66, CI 0.437-0.984) and wealth (OR 0.53, CI 0.349-0.787) lowered readmission in HRS-CMS models (N = 2068), while black (OR 1.17, CI 1.056-1.292) and 'other' race (OR 1.14, CI 1.036-1.260) increased readmission in ACS-HCUP models (N = 37,612). For acute myocardial infarction, nursing home status (OR 4.04, CI 1.212-13.440) increased readmission in HRS-CMS models (N = 833); 'other' patient-level race (OR 1.18, CI 1.012-1.385) and hospital-level race (OR 1.06, CI 1.001-1.125) increased readmission in ACS-HCUP models (N = 17,496).
  
  
  
  Disability and social determinants of health influence readmission risk when added to the current Medicare risk adjustment models, but the effect varies by condition.
authors.affiliation: Department of Internal Medicine, Division of General Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, 430W, Ann Arbor, MI, 48109, USA. meddings@umich.edu.|Department of Pediatrics and Communicable Diseases, Division of General Pediatrics, University of Michigan Medical School, Ann Arbor, MI, USA. meddings@umich.edu.|Ann Arbor VA Medical Center, Ann Arbor, MI, USA. meddings@umich.edu.|Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor, MI, USA. meddings@umich.edu.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Meddings
authors.affiliation: Department of Internal Medicine, Division of General Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, 430W, Ann Arbor, MI, 48109, USA.|Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Reichert
authors.affiliation: Department of Internal Medicine, Division of General Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, 430W, Ann Arbor, MI, 48109, USA.|University of Michigan Institute for Social Research, Ann Arbor, MI, USA.|Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Shawna N
authors.initials: SN
authors.lastname: Smith
authors.affiliation: Department of Internal Medicine, Division of General Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, 430W, Ann Arbor, MI, 48109, USA.|Ann Arbor VA Medical Center, Ann Arbor, MI, USA.|University of Michigan Institute for Social Research, Ann Arbor, MI, USA.|Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Iwashyna
authors.affiliation: Department of Internal Medicine, Division of General Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, 430W, Ann Arbor, MI, 48109, USA.|Ann Arbor VA Medical Center, Ann Arbor, MI, USA.|University of Michigan Institute for Social Research, Ann Arbor, MI, USA.|University of Michigan School of Public Health, Ann Arbor, MI, USA.|Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Langa
authors.affiliation: Department of Internal Medicine, Division of General Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, 430W, Ann Arbor, MI, 48109, USA.|Ann Arbor VA Medical Center, Ann Arbor, MI, USA.|Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Hofer
authors.affiliation: Department of Internal Medicine, Division of General Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, 430W, Ann Arbor, MI, 48109, USA.|University of Michigan School of Public Health, Ann Arbor, MI, USA.|Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Laurence F
authors.initials: LF
authors.lastname: McMahon
mesh_terms: D000203:Activities of Daily Living; D060825:Cognitive Dysfunction / Q000453:epidemiology; D015897:Comorbidity; D004185:Disability Evaluation; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D009203:Myocardial Infarction / Q000453:epidemiology; D010359:Patient Readmission / Q000191:economics / Q000706:statistics & numerical data*; D011014:Pneumonia / Q000453:epidemiology; D012189:Retrospective Studies; D020379:Risk Adjustment / Q000706:statistics & numerical data*; D064890:Social Determinants of Health / Q000706:statistics & numerical data*
keywords: Medicare; heart failure; pneumonia; readmission; risk adjustment