ObjectiveThe aim of this study was to investigate whether the acute care of frail elderly patients in a comprehensive geriatric assessment (CGA) unit is superior to the care in a conventional acute medical care unit.DesignThis is a clinical, prospective, randomized, controlled, one-center intervention study.SettingThis study was conducted in a large county hospital in western Sweden.ParticipantsThe study included 408 frail elderly patients, aged ≥75 years, in need of acute in-hospital treatment. The patients were allocated to the intervention group (n=206) or control group (n=202). Mean age of the patients was 85.7 years, and 56% were female.InterventionThis organizational form of care is characterized by a structured, systematic interdisciplinary CGA-based care at an acute elderly care unit.MeasurementsThe primary outcome was the change in health-related quality of life (HRQoL) 3 months after discharge from hospital, measured by the Health Utilities Index-3 (HUI-3). Secondary outcomes were all-cause mortality, rehospitalizations, and hospital care costs.ResultsAfter adjustment by regression analysis, patients in the intervention group were less likely to present with decline in HRQoL after 3 months for the following dimensions: vision (odds ratio [OR] =0.33, 95% confidence interval [CI] =0.14–0.79), ambulation (OR =0.19, 95% CI =0.1–0.37), dexterity (OR =0.38, 95% CI =0.19–0.75), emotion (OR =0.43, 95% CI =0.22–0.84), cognition (OR = 0.076, 95% CI =0.033–0.18) and pain (OR =0.28, 95% CI =0.15–0.50). Treatment in a CGA unit was independently associated with lower 3-month mortality adjusted by Cox regression analysis (hazard ratio [HR] =0.55, 95% CI =0.32–0.96), and the two groups did not differ significantly in terms of hospital care costs (P>0.05).ConclusionPatients in an acute CGA unit were less likely to present with decline in HRQoL after 3 months, and the care in a CGA unit was also independently associated with lower mortality, at no higher cost.