Same But Different: FIM Summary Scores May Mask Variability in Physical Functioning Profiles

Objective: To examine how similar summary scores of physical functioning using the FIM can represent different patient clinical profiles. Design: Retrospective cohort study. Setting: Inpatient rehabilitation facilities. Participants: Medicare fee-for-service beneficiaries (N=765,441) discharged from inpatient rehabilitation. Interventions: Not applicable. Main Outcome Measures: We used patients’ scores on items of the FIM to quantify their level of independence on both self-care and mobility domains. We then identified patients as requiring “no physical assistance” at discharge from inpatient rehabilitation by using a rule and score–based approach. Results: In those patients with FIM self-care and mobility summary scores suggesting no physical assistance needed, we found that physical assistance was in fact needed frequently in bathroom-related activities (eg, continence, toilet and tub transfers, hygiene, clothes management) and with stairs. It was not uncommon for actual performance to be lower than what may be suggested by a summary score of those domains. Conclusions: Further research is needed to create clinically meaningful descriptions of summary scores from combined performances on individual items of physical functioning.