Psychometric properties of the HLS-eS, an instrument to measure self-efficacy associated with healthy lifestyle behaviours in women of reproductive age

Abstract

Background: Determining self-efficacy associated with healthy lifestyle behaviours can help nurses and clinicians to treat cardiovascular risk factors in women of reproductive age to prevent them from cardiovascular disease. No psychometrically tested instrument is available yet. Instrument development resulted in the Healthy Lifestyle Self-efficacy Scale (HLS-eS), which included three subscales (diet, physical activity, and smoking). Content validity and internal consistency were assessed in women diagnosed with polycystic ovarian syndrome. Further testing on its psychometric properties was required. Aim and research question: To determine the psychometric properties of the HLS-eS in women of reproductive age. The research question was: ‘What is the internal consistency, test-retest reliability, and construct validity of the HLS-eS to measure self-efficacy associated with healthy lifestyle behaviours in women of reproductive age?’ Methods: A methodological study was conducted. The internal consistency (Cronbach’s α), test-retest reliability (Intra-class Correlation Coefficient), and construct validity including structural validity and hypothesis testing were evaluated. Results: The HLS-eS was administered by 194 reproductive-aged women. Since there were only 20 smokers, the HLS-eS included only two subscales in this study. Cronbach’s α was 0.96 for the diet subscale and 0.97 for the physical activity subscale. The Intra-class Correlation Coefficient between the test and retest was 0.88 (95% CI: 0.83 to 0.92) for the diet subscale and 0.92 (95% CI: 0.89 to 0.95) for the physical activity subscale. Factor analysis identified two factors. Self-efficacy associated with healthy lifestyle behaviours was positively correlated to general self-efficacy (r = 0.25, p = 0.001). Conclusion: The HLS-eS is reliable and valid to measure self-efficacy associated with two domains of healthy lifestyle behaviours (diet and physical activity) in highly educated, reproductive-aged women of Dutch descent. Recommendations: Item reduction is indicated. Also further testing of the instrument is required.