Date of Award
Doctor of Philosophy in Psychology
Joseph S. Rossi
High prevalence of physical inactivity in Saudi Arabia is a major public health problem that contributed to the increasing lifestyle-related diseases. Thus, interventions to promote and increase exercise are necessary. The Transtheoretical model demonstrated significant impacts in this area, however, effective interventions require psychometrically sound measures. The goal of this study is to develop, assess the psychometric properties, and confirming the factorial invariance of the Arabic versions of the Decisional Balance and Self Efficacy measures for exercise, as well as test their predicted theoretical relationships with Stages of Change with a population-based sample of Saudi adults (N=685). Three levels of invariance were tested: Configural Invariance (nonzero factor loadings unconstrained), Pattern Identity Invariance (equal factor loadings), and Strong Factorial Invariance (equal factor loadings and measurement errors). For Decisional Balance, the two-factor uncorrelated model was the most parsimonious good-fitting model (x2 (35) = 97.803, p < .001; CFI = .922; RMSEA = .076 [90% CI = .058, .093]). Internal consistency coefficient Alpha and factor rho reliability were .86 for Pros and .53 for Cons. Strong Factorial Invariance was a good fit for the model across seven grouping variables: gender, age, health status, educational level, employment status, BMI, and stage of change for exercise. The one-factor model of Self Efficacy Scale revealed an excellent fit (x2 (8) = 16.732, p = .033; CFI = .991; RMSEA = .056 [90% CI = .015, .094]). Internal consistency coefficient alpha was .86 and factor rho reliability was .89. Strong Factorial Invariance was a good fit for the model across all seven grouping variables. Multivariate analysis by stage of change replicated expected patterns for Pros (ω2= .08), Cons (ω2= .02), and Self Efficacy (ω2= .21). The results demonstrate the internal and external validity and measurement invariance of the Arabic versions of TTM measures for exercise, supporting their use in research and tailored interventions to increase exercise among Saudi population, as well as supporting the applicability of the Transtheoretical model to exercise behavior in Saudi Arabia.
Almohammadi, Iman Aly, "DEVELOPMENT AND VALIDATION OF THE ARABIC VERSIONS OF THE TRANSTHEORETICAL MODEL SCALES FOR EXERCISE" (2018). Open Access Dissertations. Paper 828.