Relationship Between Age and Trajectories of Rehospitalization Risk in Older Adults

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.

Retrospective cohort study.

U.S. hospitals (n = 4,767).

All Medicare fee-for-service beneficiaries aged 65 and older surviving hospitalization for HF, AMI, or pneumonia between October 2012 and December 2013.

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.

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.

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.