Predicting readmission and death after hospital discharge: a comparison of conventional frailty measurement with an electronic health record-based score

BACKGROUND: frailty measurement may identify patients at risk of decline after hospital discharge, but many measures require specialist review and/or additional testing. OBJECTIVE: to compare validated frailty tools with routine electronic health record (EHR) data at hospital discharge, for associations with readmission or death. DESIGN: observational cohort study. SETTING: hospital ward. SUBJECTS: consented cardiology inpatients ≥70 years old within 24 hours of discharge. METHODS: patients underwent Fried, Short Physical Performance Battery (SPPB), PRISMA-7 and Clinical Frailty Scale (CFS) assessments. An EHR risk score was derived from the proportion of 31 possible frailty markers present. Electronic follow-up was completed for a primary outcome of 90-day readmission or death. Secondary outcomes were mortality and days alive at home (‘home time’) at 12 months. RESULTS: in total, 186 patients were included (79 ± 6 years old, 64% males). The primary outcome occurred in 55 (30%) patients. Fried (hazard ratio [HR] 1.47 per standard deviation [SD] increase, 95% confidence interval [CI] 1.18–1.81, P < 0.001), CFS (HR 1.24 per SD increase, 95% CI 1.01–1.51, P = 0.04) and EHR risk scores (HR 1.35 per SD increase, 95% CI 1.02–1.78, P = 0.04) were independently associated with the primary outcome after adjustment for age, sex and co-morbidity, but the SPPB and PRISMA-7 were not. The EHR risk score was independently associated with mortality and home time at 12 months. CONCLUSIONS: frailty measurement at hospital discharge identifies patients at risk of poorer outcomes. An EHR-based risk score appeared equivalent to validated frailty tools and may be automated to screen patients at scale, but this requires further validation.