Using Functional Independence Measure Subscales to Predict Falls-Rapid Assessment.

BACKGROUND: Falls remain a major issue in inpatient rehabilitation. Decreased scores on the Functional Independence Measure (FIM), given to every patient, have been shown to predict falls risk.

PURPOSE: The aim of the study was to extend previous research using FIM to predict falls by using only subscales assessed earliest during admissions to indicate high risk of falls.

DESIGN: Retrospective cohort study.

METHODS: Two consecutive samples of patients (n1 = 1,553, n2 = 12,301) admitted to a rehabilitation hospital over 9-month and 5-year periods, respectively, were used to evaluate the predictive utility of using only a small number of FIM subscales. Subscales were selected from those assessed earliest and were related to previously published research on falls risk factors. The metric was developed using a historical data set and was validated with a second, separate group of patients. Receiver operating characteristic curves were used to evaluate predictive utility.

FINDINGS: The combination of Toileting and Expression subscales yielded a comparable area under the curve to the full FIM, and both were greater than the existing method of falls risk assessment. Likelihood of falling was strongly linearly related to score on the Toileting/Expression metric.

CONCLUSIONS: The sum of two FIM subscales can be used to predict which patients may fall during their stay in a rehabilitation hospital.

CLINICAL RELEVANCE: The FIM scores are assessed early during a patient's stay, are required for all Medicare patients, and may be useful for simple, rapid, and accurate assignment of falls risk.