Development of the Osteoporosis Self-Care Scale: Based on the Middle-Range Theory of Self-Care for Chronic Illness

Abstract

Purpose: The purpose of this study was to develop the Osteoporosis Self-Care Scale (OSCS-13) and verify its validity and reliability. Methods: The subjects were 445 patients with osteoporosis who visited the hospital. They were randomly assigned into two groups as follows: 220 patients for exploratory factor analysis and 225 patients for confirmatory factor analysis. The OSCS-13’s construct validity, convergent-discriminant validity, structure validity, group validity, consistency reliability and test-retest reliability were evaluated. Results: This study examined four factors and 13 items scored on a 5-point likert scale. The confirmatory factor analysis showed adequate model fit indices (Minimum/Degree of Freedom [CMIN/DF]=1.70, Root Mean Residual [RMR] =.03, Root Mean Square Error of Approximation [RMSEA]=.06, Comparative Fit Index [CFI]=.97, Tucker-Lewis Index [TNI]=.96, Incremental Fit Index [IFI]=.97). Convergent-discriminative validity and convergent validity were demonstrated using measures of defining issue. Internal consistency reliability and test-retest reliability were found to be acceptable, as indicated by a Cronbach’s α of.65~.92 and an intraclass correlation coefficient of.65~.80. Conclusion: The OSCS-13 is a valid and reliable instrument. Hence, it is expected that this tool can be used to measure the level of self-care for patients with osteoporosis.