Confirmatory factor analysis of the Japanese Health Locus of Control scales among people with musculoskeletal disorders

[Purpose] To determine whether the 25-item Japanese Health Locus of Control (25-JHLC) scale satisfies a 5-factor structure among Japanese with musculoskeletal disorders. [Participants and Methods] The primary inclusion criterion was people undergoing physical therapy for musculoskeletal disorders in two medical facilities. The 25-JHLC scale and demographic data were obtained by conducting an anonymous survey. Confirmatory factor analysis was used to analyze data from the 25-JHLC scale in 200 patients with musculoskeletal disorders. Fits for the 5-factor structure (1-internal; 2-family; 3-professional; 4-chance; and 5-supernatural) and the 2-factor structure (1-internal; and 2-external, including family, professional, chance, and supernatural) were studied. The goodness-of-fit criteria included chi-squared/degree of freedom, goodness-of-fit index, adjusted goodness-of-fit index, and root mean square error of approximation. [Results] The mean (standard deviation) age of the participants was 46.3 (18.3) years of age. The 2-factor structure satisfied no criteria; however, the 5-factor structure satisfied two criteria for acceptable fit (chi-squared/degree of freedom, and root mean square error of approximation). [Conclusion] This study found that the 5-factor structure of the 25-JHLC scale can be accepted to some extent among Japanese with musculoskeletal disorders without comorbidities.