To examine the structural validity, internal consistency, test-retest reliability, and construct validity of the 5-item Perceived Efficacy in Patient-Physician Interactions (PEPPI-5) scale in patients with osteoarthritis (OA).
A cross-sectional sample of 224 outpatients with OA completed a survey containing the Dutch PEPPI-5 and other standardized measures assessing perceived health-management skills, general self-efficacy, social support, and health-related quality of life. A subsample of 100 patients completed the PEPPI-5 again approximately 3 weeks later.
Confirmatory factor analysis demonstrated good fit for a unidimensional model of the PEPPI-5. Additionally, the scale showed high internal consistency (α=0.92) and fair test-retest reliability (ICC=0.68). As hypothesized, the PEPPI-5 was strongly correlated with perceived health-management skills, moderately with social support and psychosocial aspects of health, and not with physical aspects of health. Contrary to expectations, however, it was not correlated with general self-efficacy.
The PEPPI-5 is a brief and appropriate tool for measuring self-efficacy of patients with OA to interact with their physicians. Additional research into its sensitivity to change is needed before it can be confidently recommended as an outcome measure in intervention studies.
The Dutch PEPPI-5 demonstrated adequate validity and reliability in patients with OA.