Is pre-fracture functional status better than cognitive level in predicting short-term outcome of elderly hip fracture patients?

INTRODUCTION: The aim of the study was to determine to what extent severe cognitive impairment impacts short-term rehabilitation outcomes of elderly patients with proximal hip fracture. MATERIAL AND METHODS: A total of 337 community-dwelling elderly patients with acute hip fracture were observed during a 12-month period at a major teaching hospital in Serbia. Cognitive status was assessed at admission with the Short Portable Mental Status Questionnaire (SPMSQ). Outcome after 4 months was analysed with respect to presence of severe cognitive impairment, defined as an SPMSQ score of < 3. Outcome assessment included presence of postoperative complications, absolute motor Functional Independence Measure (FIM) gain, Activities of Daily Living index (ADL), Instrumental Activities of Daily Living score (IADL), and walking ability. RESULTS: An SPMSQ score of < 3 was observed in 36 patients (10.7%) with acute hip fracture. Patients with an SPMSQ score of < 3 achieved worse short-term outcomes regarding all observed variables. However, cognitive status was found to be an independent predictor only with respect to mortality at 4 months (odds ratio (OR) = 0.969, 95% confidence interval (CI) = 0.947-0.992, p = 0.009). In contrast, pre-fracture motor FIM independently predicted mortality (OR = 2.982, 95% CI = 1.271-7.000, p = 0.012), and preserved walking ability at 4 months follow-up (OR = 0.945, 95% CI = 0.912-0.980, p = 0.002). Correspondingly, pre-fracture ADL was an independent predictor of absolute motor FIM gain at 4 months follow-up (OR = 0.175, 95% CI = 0.405-11.426, p = 0.035). CONCLUSIONS: Failure to consider functional status prior to fracture might overestimate the impact of cognitive status on functional outcome of hip fracture patients.