Exploring the relationship between health beliefs and medication adherence in individuals with asthma

Abstract

In individuals with asthma, non-adherence to inhaled corticosteroids contributes to increased exacerbations, healthcare utilisation and mortality. Understanding the beliefs an individual holds about their medicines, illness and about the controllability of their health provides a promising way to better understand non-adherence in individuals with chronic conditions. Research to date has focussed on bivariate relationships between a specific set of beliefs and medication adherence. This approach simplifies the complex, multifaceted nature of medication adherence. I suggest that investigating how different beliefs associate with medication adherence in a multivariable model may improve understanding of adherence decisions.The aim of the thesis is to investigate the relationship between beliefs about medicines, illness perceptions and locus of control beliefs with self-reported medication adherence in individuals with asthma.The first part of the thesis was to identify whether beliefs about medicines, elicited through the Beliefs about Medicines Questionnaire (BMQ), were correlated to medication adherence on a population level. The BMQ consists of two scales that seek to elicit an individual's beliefs in the necessity and concerns of taking medication. Necessity beliefs reflect medicines being protective of current and future health and concern beliefs reflect beliefs about the negative effects of medicines. Beliefs about medicines are thought to play a key role in medication-taking, but inconsistent results across different conditions and different measures of adherence makes it difficult to conclude the size of the effect at a population level. A meta-analysis was conducted to identify whether beliefs in the necessity and concerns of medicines, were significantly correlated with medication adherence across different conditions. An electronic search was conducted for manuscripts comparing scores from the BMQ to measures of medication adherence. Studies were pooled using the random-effects model to produce a mean effect size correlation. Studies were stratified for condition, adherence measure, power and study design. Ninety-four papers were included and the overall effect size correlation was 0.17 for necessity and -0.18 for concerns (p<0.0001). Necessity and concerns beliefs were correlated with medication adherence on a population level and across the majority of included conditions. The effect sizes were small with a magnitude comparable to other predictors of adherence. Exploring the role of beliefs outside the Beliefs about Medicines Framework may improve prediction and understanding of medication adherence.A cross-sectional study was conducted to explore the relationship between measures of health beliefs and medication adherence in individuals with asthma. A total of 198 participants using a preventative asthma inhaler for three or more months were recruited from two community pharmacies and via iii online advertisement. Each participant completed a survey of validated questionnaires consisting of:...