The drivers of antibiotic use and misuse: The development and investigation of a theory driven community measure

Background: Antimicrobial resistance is a global public health concern, with extensive associated health and economic implications. Actions to slow and contain the development of resistance are imperative. Despite the fact that overuse and misuse of antibiotics are highlighted as major contributing factors to this resistance, no sufficiently validated measures aiming to investigate the drivers behind consumer behaviour amongst the general population are available. The objective of this study was to develop and investigate the psychometric properties of an original, novel and multiple-item questionnaire, informed by the Theory of Planned Behaviour, to measure factors contributing to self-reported antibiotic use within the community. 

Method: A three-phase process was employed, including literature review and item generation; expert panel review; and pre-test. Investigation of the questionnaire was subsequently conducted through a cross-sectional, anonymous survey. Orthogonal principal analysis with varimax rotation, Cronbach alpha and linear mixed-effects modelling analyses were conducted. A 60 item questionnaire was produced encompassing demographics, social desirability, three constructs of the Theory of Planned Behaviour including: attitudes and beliefs; subjective norm; perceived behavioural control; behaviour; and a covariate - knowledge. Results: Three hundred seventy-three participants completed the survey. Eighty participants (21%) were excluded due to social desirability concerns, with data from the remaining 293 participants analysed. 

Results showed modest but acceptable levels of internal reliability, with high inter-item correlations within each construct. All four variables and the outcome variable of antibiotic use behaviour comprised four items with the exception of social norms, for which there were two items, producing a final 18 item questionnaire. Perceived behavioural control, social norms, the interaction between attitudes and beliefs and knowledge, and the presence of a healthcare worker in the family were all significant predictors of antibiotic use behaviour. All other predictors tested produced a nonsignificant relationship with the outcome variable of self-reported antibiotic use. 

Conclusion: This study successfully developed and validated a novel tool which assesses factors influencing community antibiotic use and misuse. The questionnaire can be used to guide appropriate intervention strategies to reduce antibiotic misuse in the general population. Future research is required to assess the extent to which this tool can guide community-based intervention strategies.