The Patient-Specific Functional Scale: measurement properties in patients with knee dysfunction

Area of Science:

• Orthopedics
• Rehabilitation Medicine
• Health Outcomes Research

Background:

• Accurate disability assessment is crucial in healthcare.
• Patient-specific functional scales offer a tailored approach to measuring functional limitations.
• The Patient-Specific Functional Scale (PSFS) is a patient-reported outcome measure designed for individualized assessment.

Purpose of the Study:

• To evaluate the test-retest reliability of the PSFS in patients with knee dysfunction.
• To determine the construct validity of the PSFS using established health surveys.
• To assess the sensitivity to change of the PSFS following treatment for knee dysfunction.

Main Methods:

• The study included 38 physician-referred patients diagnosed with knee dysfunction.
• The PSFS and the Medical Outcomes Study 36-Item Short-Form Health Survey were administered at baseline and after 2-3 weeks of treatment.
• Test-retest reliability was assessed by administering the PSFS within 72 hours of the initial evaluation.

Main Results:

• The PSFS exhibited excellent test-retest reliability, with an intraclass correlation coefficient (type 2,1) of R = .84.
• Sensitivity to change was also excellent, indicated by a Pearson's r correlation of .78.
• The construct validity of the PSFS was confirmed through correlation with the SF-36 and global change assessments.

Conclusions:

• The findings support the reliability, validity, and efficiency of the PSFS for patients with knee dysfunction.
• The PSFS shows promising measurement properties, consistent with previous research on low back pain.
• Further research is recommended to explore the PSFS's applicability across diverse conditions and age groups.