Purpose: To develop and provide initial psychometric support for a 16-item measure that assesses a new construct termed desire for physical competence (DPC).
Methods: A total of 157 older adults (aged 60-95) were administered the DPC along with various other questionnaires that assessed demographics, health status, social desirability, desire for control, body satisfaction, and life satisfaction. These data facilitated development and initial psychometric evaluation of the scale. An additional sample of 30 older adults was employed to examine test-retest reliability.
Results: Based on the conceptual foundation of DPC and results from an exploratory factor analysis, a single-dimension Rasch model based on response theory was applied to the data. The proposed model fit the data quite well as indicated by the average mean square of both outfit (1.02) and infit (1.04) statistics. The DPC correlated in expected directions with age, r = -0.33 (P < 0.01), and had r values of 0.23, 0.22, 0.25 (all P values <0.01) with desire for control, body satisfaction, and the SF-36, respectively. Older adults with arthritis had lower DPC scores than those without arthritis. The measure was not confounded by social desirability, and test-retest reliability of the measure (>0.90) was excellent.
Conclusions: The DPC provides a tool to assess the incentive value of older adults for being physically competent. As such, it provides a more complete social cognitive foundation for studies examining physical activity behavior and the process of physical disablement.