Previous disability as a predictor of outcome in a geriatric rehabilitation unit

Background. Functional status at admission has been shown consistently to predict rehabilitation results, but the impact of previous disability has been seldom considered. Methods. A prospective follow-up study of elderly patients admitted to a geriatric rehabilitation unit in Madrid, Spain, was carried out. The study population comprised 135 subjects aged 65 years or older, who were consecutively admitted during a 7-month period. Outcome variables included the Barthel Index (BI) at discharge, the improvement in BI from admission to discharge, the achieved percentage of potential gain, and the efficiency of gains. Previous BI, admission BI, diagnosis, source (hospital/others), mental status: age, and gender were examined as explanatory variables. Results. In multiple regression analysis, previous BI was the only significant independent predictor for all the outcome variables. For each 5-point increase in previous BI, the increase in BI at discharge was 1.7 (p = .007). Corresponding values for the achieved percentage of potential gain and for the efficiency of gains were 0.05 (p = .01) and 0.05 (p = .01), respectively. Except for the achieved percentage of potential gain, admission BI and source of referral were also independent significant predictors of outcome. Conclusions. Previous functional situation of elderly people is important to predict rehabilitation outcome, even after taking into account information on disability at admission. Asa consequence, a measure of the achieved percentage of potential gain corrected by the preadmission functional status is proposed, especially in the case of elderly patients.