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.