Objectives: To determine the effect of cognitive status at admission on functional gain during rehabilitation of elderly hip-fractured patients.
Design: Cohort study.
Setting: A hospital geriatric rehabilitation department.
Patients: Two hundred twenty-four elderly patients admitted consecutively for rehabilitation after surgery for hip fracture.
Measurements: Cognitive status was assessed by the Mini-Mental State Examination and the cognitive subscale of the Functional Independence Measure (cognFIM); functional status was assessed by the motor subscale of FIM; absolute functional gain was determined by the motor FIM gain (deltamotFIM); and relative functional gain (based on the potential for improvement) by the Montebello rehabilitation factor score (MRFS).
Results: A significant increase in FIM scores (19.7) occurred during rehabilitation, mainly due to motor functioning (19.1). When the relative functional gain (as measured by both motor MRFS efficacy [r = .591] and efficiency [r = .376] was compared with the absolute gain (as measured by deltamotFIM [r = .304]), a stronger association between cognFIM and the relative measures was found. In addition, motor FIM efficacy and efficiency were significantly lower in the cognitively impaired patients (p<.01). A better rehabilitation outcome was seen in patients with higher admission cognitive status, adjusting for the effects of age, sex, length of stay, and type of fracture (odds ratio = 2.2, 95% confidence interval 1.5-3.7).
Conclusions: Impaired cognitive status at admission lowered the rehabilitation outcome of elderly hip fracture patients. Cognitive impairment was strongly and directly associated with functional gain in these patients. Absolute motor gain appeared to be independent of cognitive status, whereas the relative motor gain depended on it. These findings support the implementation of comprehensive rehabilitation for selected cognitively impaired elderly hip fracture patients.