Published: Journal of Orthopaedic & Sports Physical Therapy, 2014 Volume:44 Issue:8 Pages:560–564 DOI: 10.2519/jospt.2014.5248
Abstract
Study Design
Multicenter, prospective, longitudinal cohort study.
Objectives
To investigate the minimum important difference (MID) of the Patient-Specific Functional Scale (PSFS), 4 region-specific outcome measures, and the numeric pain rating scale (NPRS) across 3 levels of patient-perceived global rating of change in a clinical setting.
Background
The MID varies depending on the external anchor defining patient-perceived “importance.” The MID for the PSFS has not been established across all body regions.
Methods
One thousand seven hundred eight consecutive patients with musculoskeletal disorders were recruited from 5 physical therapy clinics. The PSFS, NPRS, and 4 region-specific outcome measures-the Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale-were assessed at the initial and final physical therapy visits. Global rating of change was assessed at the final visit. MID was calculated for the PSFS and NPRS (overall and for each body region), and for each region-specific outcome measure, across 3 levels of change defined by the global rating of change (small, medium, large change) using receiver operating characteristic curve methodology.
Results
The MID for the PSFS (on a scale from 0 to 10) ranged from 1.3 (small change) to 2.3 (medium change) to 2.7 (large change), and was relatively stable across body regions. MIDs for the NPRS (−1.5 to −3.5), Oswestry Disability Index (−12), Neck Disability Index (−14), Upper Extremity Functional Index (6 to 11), and Lower Extremity Functional Scale (9 to 16) are also reported.
Conclusion
We reported the MID for small, medium, and large patient-perceived change on the PSFS, NPRS, Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale for use in clinical practice and research. J Orthop Sports Phys Ther 2014;44(8):560–564. Epub 14 May 2014. doi:10.2519/jospt.2014.5248