Invariance Testing of the Disablement in the Physically Active Scale Short Form-10.

Context: Psychometrically sound instruments are needed to accurately track the effectiveness of treatment and assess the quality of patient care. The Disablement in the Physically Active (DPA) scale Short Form-10 (SF-10) was developed as a more parsimonious version of the Disablement in the Physically Active scale to assess disablement in the physically active. Psychometric assessment of the DPA SF-10 has not been completed; specifically, the scale properties must be assessed among a sample of individuals who respond only to the 10-item scale at multiple time points.

Objective: To assess the psychometric properties of the DPA SF-10 using confirmatory factor analysis and invariance procedures across multiple time points.

Main Outcome Measure(s): Confirmatory factor analyses and longitudinal invariance tests were conducted.

Results: The DPA SF-10 met contemporary fit index recommendations and demonstrated longitudinal invariance; however, localized fit concerns suggest further modification is needed.

Conclusions: Adoption of the DPA SF-10 into widespread clinical practice and research is not recommended until further psychometric testing and scale modification are performed.