Time-dependent prognostic factors of 6-month mortality in frail elderly patients admitted to post-acute care

Objective: to determine the association between functional and nutritional changes caused by an acute illness requiring hospitalisation and 6-month mortality. Design: hospital-based prospective longitudinal cohort study. Setting: acute care centre (Hospital General de Vic, Barcelona Province, Spain). Post-acute care centre (Hospital de la Santa Creu de Vic, Barcelona Province, Spain). Subjects: hundred sixty five patients aged 75 years and older, hospitalised for an acute event. Methods: functional status (Barthel and Lawton Indices), cognitive status (Short Portable Mental Status Questionnaire), nutritional status (Mini Nutritional Assessment, albumin, cholesterol), depressive symptoms (Geriatric Depression Scale), co-morbidity (Charlson Index) and self-rated health status were collected upon admission to the Post-acute care centre. Functional and nutritional status were assessed 1, 3 and 6 months after admission by a trained staff of geriatricians. Six-month mortality was the main outcome variable. Survival analysis was performed with functional and nutritional status as time-dependent variables. Results: the mean age of the cohort was 83.3 years (SD 5.1) and 68.5% were female. Six-month mortality was 29.1% (95% CI: 22.2-36.7). The variables associated with mortality in bivariate analysis were: gender, Barthel Index (2 weeks before admission), Lawton Index (2 weeks before admission), Charlson Index, Barthel Index (time-dependent), Mini Nutritional Assessment (MNA) (time-dependent) and cognitive status. The variables associated with mortality in multivariate analysis were: gender, Barthel Index (2 weeks before admission), Charlson Index and MNA (time-dependent). Conclusions: functional and nutritional changes due to an acute illness have a statistical and clinical prognostic value and should be assessed along with other well-known relevant prognostic factors.