Short-form Activity Measure for Post-acute Care

Objective: To develop a comprehensive set of short forms using item response theory (IRT) and item pooling procedures for the purpose of monitoring postacute care functional recovery.

Design: Prospective study.

Setting: Six postacute health care networks in the greater Boston area, including inpatient acute rehabilitation, transitional care units, home care, and outpatient services.

Participants: A convenience sample of 485 adult volunteers who were currently receiving skilled rehabilitation services.

Interventions: Not applicable.

Main Outcome Measures: We developed a set of 6 short forms across 3 activity domains from new items and items from existing postacute care instruments.

Results: Inpatient- and community-based short forms were developed for each of 3 activity domains: physical & movement, applied cognition, and personal care & instrumental. Items were selected for inclusion on the short forms to maximize content coverage and information value of items across the range of content and to minimize ceiling and floor effects. We were able to match the distribution of sample scores with very good item precision for 1 of the constructs (physical & movement); the other 2 domains (personal care & instrumental, applied cognition) were more challenging because of the variability in patient recovery and ceiling effects.

Conclusions: ITR methods and item pooling procedures were valuable in developing paired sets of short-form instruments for inpatient and community rehabilitation that provided estimates of functioning along a common metric for use across postacute care settings.