Frailty, underweight and impaired mobility are associated with institutionalisation after post-acute care

Post-acute care (PAC) is intended for older adult patients who are unable to return home directly after acute hospitalisation but who do not otherwise qualify for specific rehabilitation. However, data on potential predictors of PAC outcomes remain limited. Our aim was to identify patient characteristics upon admission to PAC that are associated with subsequent institutionalisation.

Prospective cohort study enrolling 140 former acute care inpatients aged 60 and older who were referred to PAC units at nursing homes in Zurich, Switzerland.

Geriatric assessment at admission included Barthel Index (BI), Short Physical Performance Battery (SPPB), frailty status (Fried phenotype), nutrition and cognitive status. Logistic regression was used to determine statistically significant associations.

Mean age was 84.1 (standard deviation [SD] 8.6) years; 62.9% of participants were women. Mean body mass index (BMI) was 25.0 (SD 5.8) kg/m2, with 12.1% being underweight (BMI <20 kg/m2). Mean BI at admission was 62.1 (SD 19.1), mean SPPB score was 5.2 (SD 2.8), and 55% were frail (≥3 Fried criteria present). After a mean length of stay in PAC of 30.9 (SD 16.5) days, 48.6% were institutionalised. Patients who were frail at admission had a 2.97-fold higher (odds ratio [OR] 2.9,7 95% confidence interval [CI] 1.04–8.42), and patients who were underweight had a 4.94-fold higher (OR 4.94, 95% CI 1.11–22.01) chance of institutionalisation. Conversely, each points increment on the SBBP score lowered the likelihood of institutionalisation by 23% (OR 0.77, 95% CI 0.65–0.92).

Frailty, low Short Physical Performance Battery score and being underweight at admission to PAC were significantly associated with a higher chance of subsequent institutionalisation. Strategies to improve these factors could improve post-acute care outcomes.