Age-related differences in the rate and diagnosis of 30-day readmission after hospitalization for acute ischemic stroke

Background Little is known about the association between age and readmission within 30 days after hospitalization for acute ischemic stroke. Aim To examine the age-related differences in rate and principal reason of 30-day readmissions in patients hospitalized for acute ischemic stroke. Methods In this retrospective, population-based cohort study using State Inpatient Databases from eight US states, we identified all adults hospitalized for acute ischemic stroke. We grouped the patients into four age categories: < 65, 65-74, 75-84, and ≥85 years. Outcomes were any-cause readmission within 30 days of discharge from the index hospitalization for acute ischemic stroke and the principal diagnosis of 30-day readmission. Results We identified 620,788 hospitalizations for acute ischemic stroke. The overall 30-day readmission rate was 16.6% with an increase with advanced age. Compared to patients aged <65 years, the readmission rate was significantly higher in age 65-74 years (OR 1.19; 95% CI 1.16-1.21), in age 75-84 years (OR 1.29; 95% CI 1.27-1.31), and in ≥ 85 years (OR 1.24; 95% CI 1.22-1.27; all P<0.001). There was heterogeneity in the age-readmission rate association between men and women (P interaction  < 0.001). Overall, 45.8% of readmissions were assigned stroke-related conditions or rehabilitation care. Compared to younger adults, older adults were more likely to present with non-stroke-related conditions (46.1% in < 65 years, 50.6% in 65-74 years, 57.1% in 75-84 years, and 62.9% in ≥ 85 years; P<0.001). Conclusions Advanced age was associated with a higher 30-day readmission rate after acute ischemic stroke. Compared with younger adults, older adults were more likely to be readmitted for non-stroke-related conditions.