Age-Related Differences in the Rate, Timing, and Diagnosis of 30-Day Readmissions in Hospitalized Adults With Asthma Exacerbation.

BACKGROUND: Reducing hospital readmissions has attracted attention from many stakeholders. However, the characteristics of 30-day readmissions after asthma-related hospital admissions in adults are not known. It is also unclear whether older adults are at higher risk of 30-day readmission.

OBJECTIVES: To investigate the rate, timing, and principal diagnosis of 30-day readmissions in adults with asthma and to determine age-related differences.

METHODS: Retrospective cohort study of adults hospitalized for asthma exacerbation using the population-based inpatient samples of three states (California, Florida, and Nebraska) from 2005 through 2011. Patients were categorized into three age groups: younger (18-39 years), middle aged (40-64 years), and older (≥ 65 years) adults. Outcomes were 30-day all-cause readmission rate, timing, and principal diagnosis of readmission.

RESULTS: Of 301,164 asthma-related admissions at risk for 30-day readmission, readmission rate was 14.5%. Compared with younger adults, older adults had significantly higher readmission rates (10.1% vs 16.5%; OR, 2.15 [95% CI, 2.07-2.23]; P < .001). The higher rate attenuated with adjustment (OR, 1.19 [95% CI, 1.13-1.26]; P < .001), indicating that most of the age-related difference is explained by sociodemographics and comorbidities. For all age groups, readmission rate was highest in the first week after discharge and declined thereafter. Overall, only 47.1% of readmissions were assigned respiratory diagnoses (asthma, COPD, pneumonia, and respiratory failure). Older adults were more likely to present with nonrespiratory diagnoses (41.7% vs 53.8%; P < .001).

CONCLUSIONS: After asthma-related admission, 14.5% of patients had 30-day readmission with wide range of principal diagnoses. Compared with younger adults, older adults had higher 30-day readmission rates and proportions of nonrespiratory diagnoses.