Article

The increasing use of computerized adaptive tests (CATs) to generate
outcome measures during rehabilitation has prompted questions concerning score
interpretation. OBJECTIVE: The purpose of this study was to describe meaningful
interpretations of functional status (FS) outcome measures estimated with a body
part-specific CAT developed from the Lower-Extremity Functional Scale (LEFS).
DESIGN: This investigation was a prospective cohort study of 8,714 people who had
hip impairments and were receiving physical therapy in 257 outpatient clinics in
31 states (United States) between January 2005 and June 2007. METHODS: Four
approaches were used to clinically interpret outcome data. First, the standard
error of the estimate was used to construct the 90% confidence interval for each
CAT-generated score estimate. Second, percentile ranks were applied to FS scores.
Third, 2 threshold approaches were used to define individual subject-level
change: statistically reliable change and clinically important change. The fourth
approach was a functional staging method. RESULTS: The precision of a single
score was estimated from the FS score +/-4. On the basis of the score
distribution, 25th, 50th, and 75th percentile ranks corresponded to intake FS
scores of 40, 48, and 59 and discharge FS scores of 50, 61, and 75, respectively.
The reliable change index supported the conclusion that changes in FS scores of 7
or more units represented statistically reliable change, and receiver operating
characteristic analyses supported the conclusion that changes in FS scores of 6
or more units represented minimal clinically important improvement. Participants
were classified into 5 hierarchical levels of FS using a functional staging
method. LIMITATIONS: Because this study was a secondary analysis of prospectively
collected data via a proprietary database management company, generalizability of
results may be limited to participating clinics. CONCLUSIONS: The results
demonstrated how outcome measures generated from the hip LEFS CAT can be
interpreted to improve clinical meaning. This finding might facilitate the use of
patient-reported outcomes by clinicians during rehabilitation services.

Langue : ANGLAIS