Frailty predicts some but not all adverse outcomes in older adults discharged from the emergency department

OBJECTIVES: To determine whether frail older adults, based on a deficit accumulation index (DAI), are at greater risk of adverse outcomes after discharge from the emergency department (ED). DESIGN AND SETTING: Secondary analysis of data from the Medicare Current Beneficiary Survey. PARTICIPANTS: One thousand eight hundred fifty-one community-dwelling Medicare fee-for-service enrollees, aged 65 and older who were discharged from the ED between January 2000 and September 2002. MEASUREMENTS: The primary dependent variable was time to first adverse outcome, defined as repeat outpatient ED visit, hospital admission, nursing home admission, or death, within 30 days of the index ED visit. RESULTS: Time to first adverse outcome was shortest in individuals with the highest number of accumulated deficits. The frailest participants were at greater risk of adverse outcomes after ED discharge than those who were least frail (hazard ratio (HR)=1.44, 95% confidence interval (CI)=1.06-1.96). The frailest individuals were also at higher risk of serious adverse outcomes, defined as hospitalization, nursing home admission, or death (HR=1.98, 95% CI=1.29-3.05). In contrast, no association was detected between degree of frailty and repeat outpatient ED visits within 30 days (HR=1.06, 95% CI=0.73-1.54). CONCLUSION: The DAI as a construct of frailty was a robust predictor of serious adverse outcomes in the first 30 days after ED discharge. Frailty was not found to be a major determinant of repeat outpatient ED visits; therefore, additional study is needed to investigate this particular type of health service use by older adults.