The Patient-Specific Functional Scale was valid for group-level change comparisons and between-group discrimination

Area of Science:

• Rehabilitation Science
• Clinical Measurement
• Health Outcomes Research

Background:

• The Patient-Specific Functional Scale (PSFS) is a patient-reported outcome measure used to assess functional status.
• Its validity for group-level analysis in clinical research requires thorough examination.
• Understanding the psychometric properties of the PSFS is crucial for its appropriate application.

Purpose of the Study:

• To evaluate the validity of the Patient-Specific Functional Scale (PSFS) for assessing group-level change.
• To determine the PSFS's ability to discriminate between groups in large-scale clinical data.
• To confirm the PSFS's suitability for statistical comparisons in research settings.

Main Methods:

• Collected baseline and follow-up PSFS data from 1,181 patients with musculoskeletal disorders.
• Assessed concurrent, convergent, and discriminant validities using correlation and regression analyses.
• Utilized ANOVA and Cohen's d to evaluate between-group discrimination and responsiveness.

Main Results:

• The PSFS demonstrated strong concurrent, convergent, and discriminant validities (P < 0.001).
• The scale showed good distribution, consistency, and responsiveness for group-level data.
• The PSFS outperformed other patient-reported outcome measures in most comparisons.

Conclusions:

• The Patient-Specific Functional Scale (PSFS) is a valid and reliable measure for group-level statistical comparisons in clinical research.
• Findings support the use of the PSFS for assessing change over time and discriminating between groups.
• The PSFS is recommended for clinical research involving patient populations with musculoskeletal disorders.