Self-regulation and self-management in asthma: exploring the role of illness perceptions and treatment beliefs in explaining non-adherence to preventer medication

The present study was designed to evaluate the degree to which variations in reported adherence to preventer medication for asthma could be explained by two sets of beliefs: perceptions of asthma and perceptions of asthma medication (beliefs about its necessity and concerns over its use). It also begins the empirical testing of an extended self-regulatory model, which includes treatment beliefs as well as illness perceptions. Using a cross-sectional design, 100 community-based patients completed validated questionnaires assessing their perceptions of asthma, beliefs about preventer inhalers and reported adherence to them. The findings showed that non-adherent behaviours were associated with doubts about the necessity of medication and concerns about its potential adverse effects and with more negative perceived consequences of illness. A hierarchical linear regression analysis revealed that socio-demographic and clinical factors explained only a small amount of variance in adherence whereas illness perceptions and treatment beliefs were both more substantial independent predictors. The best fit Amos analysis showed that illness perceptions influenced adherence both directly and indirectly via treatment beliefs, which, in turn, were the strongest predictors. The findings lend preliminary support for an extended self-regulatory model of treatment adherence, which incorporates beliefs about treatment as well as illness perceptions