Hospital Readmissions Following Cardiovascular Events

Reducing hospital readmissions has become a top priority for health policy due to high costs to the healthcare system. Hospital readmissions are especially noted in the older population, with 1 in 5 Medicare beneficiaries being readmitted within 30 days of discharge. However, many young and middle-age adults 18 to 64 years of age also experience hospital readmissions. Previous studies have found that patients <65 years of age account for 30% of heart failure admissions, 40% to 45% of acute myocardial infarction (MI) admissions, and 33% of pneumonia admissions. In addition, patients in this age group consume 32% to 44% of aggregated costs for these 3 conditions.

Because an understanding of hospital readmissions in younger patients is lacking, a recent study sought to compare the rate, timing, and readmission diagnoses for these 3 conditions in patients 18 to 64 years of age [PLoS One. 2014;11(9):e1001737].

For this study, Medicare claims data were used for patients ≥65 years of age for comparison. The researchers then identified hospitalizations from California included in the all-payer Healthcare Cost and Utilization Project state inpatient dataset and derived 3 cohorts of hospitalizations with a discharge diagnosis of heart failure (n=206,141), acute MI (n=107,256), or pneumonia (n=199,620) between January 2007 and November 2009. Hospitalizations for patients who died, were transferred to another hospital, or were discharged against medical advice were not included in the study.

The study’s primary outcomes were unplanned 30-day readmission rate, timing of readmission, and readmission diagnosis.

Overall, the researchers found a 22.4% readmission rate for heart failure, 15% readmission rate for acute MI, and 16.3% readmission rate for pneumonia (Table). Specifically, the readmission rate for heart failure patients was higher among those 18 to 64 years of age compared with the ≥65 years of age cohort (23.4% vs 22%, respectively; P<.001). The readmission rate for acute MI was lower among those 18 to 64 years of age compared with the ≥65 years of age cohort (11.2% vs 17.5%, respectively; P<.001). In addition, the readmission rate for pneumonia was lower among those 18 to 64 years of age compared with the ≥65 years of age cohort (14.4% vs 17.3%, respectively; P<.001).

The 30-day readmission risk in patients 18 to 64 years of age was similar to patients ≥65 years of age for heart failure (hazard ratio [HR], 0.99; 95% confidence interval [CI], 0.97-1.02) and pneumonia (HR, 0.97; 95% CI, 0.94-1.01) but was marginally lower in the acute MI cohort (HR, 0.92; 95% CI, 0.87-0.96).

In addition, for all age cohorts, the timing of readmission was similar. Risk of readmission was highest between days 2 and 5.

The researchers noted limitations of the study. The data were derived from just 1 state. Also, out-of-hospital deaths were not accounted for, which may be disproportionately higher among older patients, which would result in a lower observed rate of readmissions among this patient population compared with younger adults.

The researchers concluded that a generalized risk of rehospitalization is present in patients regardless of age.—Kerri Fitzgerald