This study examines whether the relationships between activity limitations and independence are mediated by coping efficacy.
Data come from a cross-sectional survey of 286 adults, aged 55 or older, with osteoarthritis (OA) and/or osteoporosis (OP). Physical independence was assessed by asking to what extent respondents' OA/OP had affected their independence on a 5-point scale from 'not at all' to 'a great deal'. Activity limitations were examined in three domains: personal care, community mobility, and household activity. A coping efficacy scale was derived from three items scored on a 5-point Likert-type scale from strongly disagree to strongly agree. Structural equation modelling was used to test the model.
Activity limitation in household activities was directly associated with perceptions of independence, with a statistically significant standardized path coefficients of -0.32. The effect of activity limitation in personal care was partially mediated by coping efficacy with a direct effect of -0.41 which was partially offset by coping efficacy to give a net effect of -0.308. The effect of community mobility on independence was completely mediated through coping efficacy with significant standardized path coefficients of -0.85 (community mobility to coping efficacy) and -0.14 (coping efficacy to independence). The overall model's goodness of fit was excellent (R =0.59, ch-square/df=1.4, CFI=0.97, and NNFI=0.97).
Activity limitation had a detrimental effect on the level of self-perceived independence. Coping efficacy showed a significant mediating effect between activity limitation and self-perceived independence for the domains of personal care and community mobility, but not household tasks. This study suggests that how activity limitation affects perceptions of independence varies across activity limitation domains, and indicates the importance of incorporating activity limitation domains in future studies.