Abstract
OBJECTIVES: To characterize the magnitude and duration of risk of rehospitalization according to age after hospitalization for heart failure (HF), acute myocardial infarction (AMI), or pneumonia. DESIGN: Retrospective cohort study. SETTING: U.S. hospitals (n = 4,767). PARTICIPANTS: All Medicare fee-for-service beneficiaries aged 65 and older surviving hospitalization for HF, AMI, or pneumonia between October 2012 and December 2013. MEASUREMENTS: Daily risk of first rehospitalization for 1 year after hospital discharge was calculated according to age category (65-74, 75-84, ≥85) after adjustment for sex, race, comorbidities, and median ZIP code income. Time required for adjusted rehospitalization risk to decline 50% from maximum value after discharge, time required for adjusted risk to approach a plateau period of minimal day-to-day change, and degree to which adjusted risk was higher in recently hospitalized individuals than in the general elderly population were identified. RESULTS: There were 414,720 hospitalizations for HF, 177,752 for AMI, and 568,304 for pneumonia. The adjusted risk of rehospitalization declined with increasing age after HF hospitalization (P < .001), rose with increasing age after AMI hospitalization (P < .001), and was slightly lower with increasing age after pneumonia hospitalization (P = .002). Adjusted risks of rehospitalization were high beyond 30 days after hospitalization for all ages. CONCLUSION: Although older age has heterogeneous relationships with rehospitalization risk, risk of readmission remains high for an extended time after discharge regardless of age or admitting condition. Condition-specific data on risk can be used to guide discussions on advanced care planning and strategies for longitudinal follow-up after hospitalization.