Psychosocial correlates of stages of change in physical activity in an adult community sample

Abstract

Two important public health challenges are to influence sedentary people to become physically active, and to influence active people to maintain their level of activity. Psychosocial factors might have important influencing properties in this regard. The aims of this study were threefold: (1) to examine the relationships between selected psychosocial factors and physical activity stages of change; (2) to examine moderating influences of socio-demographic and anthropometric factors in these relationships; and (3) to identify possible interactions between psychosocial factors in their relation to stages of change. Altogether, 2336 men and women aged 31–67 (mean 48, s=10) years completed self-administered questionnaires that assessed stages of change in physical activity, self-efficacy, social support, perceived behavioural control, attitude, and identity. The psychosocial factors were measured by instruments derived or modified from instruments that have previously been shown to have acceptable validity and reliability. The statistical tests employed were descriptive and frequency analyses, Pearson's correlations, multiple regressions, multivariate analyses of variance, analyses of variance, and Tukey post-hoc comparison tests. Analyses revealed that self-efficacy in the face of psychological barriers, support from family and from friends, perceived behavioural control, and identity explained 42% of the variance in stages of physical activity behaviour change. Results further showed that all measured psychosocial variables differed significantly by stages of change, with almost every stage having significantly different psychosocial variable scores than every other stage. Although we found no moderating effects of socio-demographic or anthropometric variables on these relationships, social support from family and social support from friends, identity and social support from family, as well as perceived behavioural control and self-efficacy faced with psychological barriers were found to interact with respect to their relationships with stages of change. The study identified a strong set of psychosocial correlates of physical activity stages of change as well as significant interactions between particular correlates in these relationships. The findings might provide guidance in the design of stage-matched interventions to promote physical activity among adults. Further work is needed to confirm these findings as well as to provide evidence of the causality in the observed relationships.