T T CONCLUSION:Although the use of the PSFS as an outcome measure is increasing in physiotherapy practice, there are gaps in the research literature regarding its validity, reliability, and responsiveness in many health conditions.

Study Design Clinical measurement, longitudinal; multicenter prospective cohort study. Objectives To examine the validity, reliability, and responsiveness of the Patient-Specific Functional Scale (PSFS) in patients with musculoskeletal upper extremity problems being treated in physical therapy. Background The clinimetric properties of the PSFS have not been established nor compared with region-specific outcome measures in patients with upper extremity problems. Methods Patients completed the PSFS, Upper Extremity Functional Index (UEFI), and numeric pain rating scale (NPRS) at baseline and follow-up, and were categorized as improved, stable, or worsened, using the global rating of change. Construct validity was assessed by comparing the change scores of the stable and improved groups, using independent-samples t tests. Reliability was evaluated using intraclass correlation coefficient (ICC2,1) with 95% confidence intervals. Bland-Altman plots determined limits of agreement. Responsiveness and minimal important difference (MID) were determined with receiver operator characteristic (ROC) curves. Results One hundred eighty patients met the inclusion criteria. Construct validity was supported for the PSFS and the UEFI (P<.001). Reliability was moderate to good for the PSFS (ICC2,1 = 0.713) and UEFI (ICC2,1 = 0.848). Reported estimates of reliability may be lower than true values because the group of “stable” patients from this cohort had, on average, a small positive change. Bland-Altman plots indicated good agreement. The area under the ROC curve (AUC) was significantly different from the null value of 0.5 for the PSFS (0.887) and the UEFI (0.877), indicating good accuracy in distinguishing improved patients from stable patients. MID was 1.2 for the PSFS (scale, 0–10) and 8.5 for the UEFI (scale, 0–80). Conclusion The PSFS is a valid, reliable, and responsive outcome measure for patients with upper extremity problems. J Orthop Sports Phys Ther 2012;42(2):56–65. doi:10.2519/jospt.2012.3953

No abstract

The ICF activity component was most commonly represented by patient-nominated PSFS items, the participation component was moderately represented, and impairment was least represented. Hence, the PSFS would complement impairment-based clinical outcome measures.