Permanent cognitive or physical impairment after transfer from long-term care to acute care: a retrospective cohort study

BACKGROUND: Long-term care (LTC) residents are frequently transferred to emergency departments (ED), which may increase the risk of impairment. OBJECTIVE: To examine associations between all-cause ED transfers and development of new permanent severe physical and cognitive impairments, and death. SETTING AND PARTICIPANT: Adults ≥65 with incident admission to LTC homes in Ontario, Canada between 2013 and 2018. METHODS: We conducted a retrospective cohort study. We examined rates of (i) severe physical impairment, (ii) severe cognitive impairment and (iii) all-cause mortality after transfer to ED. We used marginal structural models to estimate the combined effect of acute illness and ED transfer. We used an instrumental variable (IV) analysis to isolate the effect of transfer, adjusting for acute illness. RESULTS: Of 120,238 residents, 78,546 (65.3%) residents had at least one transfer to the hospital. The mean (SD) age was 84.6 (7.9) years, 67.2% were female. The incidence rate ratios were 3.0 (95% CI, 2.9-3.1) for new physical impairment, 2.2 (95% CI, 2.1-2.3) for cognitive impairment and 5.8 (95% CI, 5.7-5.9) for mortality, comparing transferred to never-transferred residents. In IV analysis, transfers were not associated with permanent physical or cognitive impairment (hazard ratio [HR] (95% CI) [HR1.20] (0.92-1.55); [HR0.86] (0.69-1.06), but were associated with decreased mortality [HR0.57] (CI 0.50-0.63). CONCLUSION: In unadjusted analyses, residents transferred to ED had a higher incidence of permanent physical impairment, cognitive impairment and mortality. After adjusting for acute illness, transfer decisions were not associated with changes in the risk of severe impairment and were associated with reduced mortality.