Interpreting rehabilitation outcome measurements

Objective: With the increased use of standardized outcome instruments in rehabilitation, questions frequently arise as to how to interpret the scores that are derived from these standardized outcome instruments. This article uses examples drawn from the Activity Measure for Post Acute Care to illustrate 4 different data analysis and presentation strategies that can be used to yield meaningful outcome data for use in rehabilitation research and practice. Design: A prospective cohort study in patients recruited at the point of discharge from a large acute care hospital or on admission to 1 of 2 rehabilitation hospitals after discharge from an acute care hospital in the greater Boston, MA region. Sample: A total of 516 subjects in the Rehabilitation Outcome Study. Results: Four distinct approaches to analyzing and reporting outcome data are described to derive more meaningful outcome measurements: interpreting a single scale score; interpreting clinical significance of score changes; a percentile ranking method; and a functional staging approach. The first 3 methods focus on interpreting the numeric property of individual measurements and are best suited to assess individual outcomes and for detecting change. The fourth, a functional staging approach, provides an attractive feature of interpreting the clinical meaning provided by a particular quantitative score without sacrificing the inherent value of a quantitative scale for tracking change over time. Conclusion: Users are encouraged to consider the range of analysis and presentation strategies available to them to evaluate a standardized scale score, both from a quantitative and a content perspective.