Validity and Reliability of the Index of Self-Regulation Scale for Physical Activity in Older Korean Americans

The Korean version of the index of self-regulation (KISR) is a nine-item scale designed to measure individuals' level of self-regulation for physical activity. The purpose of this study was to test the psychometric properties of the KISR, including reliability and validity, in a group of older Korean Americans. The KISR was administered to a sample of older Korean Americans at a baseline interview (Time 1) and 12 week followup (Time 2). The internal consistency of the KISR was high at both time points, with Cronbach's alphas of .94 and .95, respectively. The test-retest reliability was moderate-to-high at .68. There was evidence of construct validity of the KISR based on its moderate to high significant correlations with theoretically relevant variables, including motivational appraisal and self-efficacy for physical activity. A principal axis factoring with an oblique rotation resulted in two factors, explaining 89% of the variance. The KISR is a reliable and valid measure to assess the level of self-regulation for physical activity behavior in older Korean Americans.