DOI: 10.1080/16501970600609774

Objective: To examine the sensitivity of the Short Form Activity Measure for Post-Acute Care (AM-PAC) in comparison to the Functional Independence Measure (FIM™) across a 12-month period after discharge from rehabilitation hospital. Design: Prospective longitudinal study. Patients were recruited while receiving inpatient services from facilities in the north-east USA and interviewed 1, 6 and 12 months thereafter. Patients: Convenience sample of 516 patients at baseline (65% retention at the final follow-up) receiving rehabilitation services for neurological, lower extremity orthopedic, or complex medical conditions. Mean age 68. 3 years; 47% male. Main outcome measures: AM-PAC Physical and Movement, Personal Care and Instrumental, and Applied Cognitive Activity scales; FIM™ Motor and Cognitive scales. Results: All 3 AM-PAC scales were sensitive to both positive and negative change across the follow-up period. Standardized response means for the AM-PAC were consistently larger than for the FIM™ across patient and severity groups. A greater percentage of patients showed positive change that exceeded the minimal detectable change on the AM-PAC than on the FIM™ at both 6- and 12-month follow-ups. Conclusion: The short-form AM-PAC scales are more sensitive measures of change in functional activity performance over time in the general population of persons who receive inpatient rehabilitation services compared to the FIM™. Thus, the AM-PAC offers a short, comprehensive, and sensitive measure of positive and/or negative change in patients' ability to perform important activities of daily life.