Theory-Based Approaches and Determinants of Disease Prevention Behaviours

Disease prevention, especially during outbreaks, often involves behavioural factors to reduce community transmission and spread of pathogens. During the COVID-19 pandemic, many behaviour-based interventions were introduced such as physical distancing, mask use, hand hygiene, and vaccinations, all of which have been shown to combat the spread of infectious diseases. However, there were concerns and reports about uptake of these behaviours and noncompliance during the pandemic which diminished the effectiveness of existing interventions aimed at improving public health. Therefore, the aim of this work was to: (a) use theory-based approaches to investigate the determinants of these behaviours, with an emphasis on environmental determinants, and (b) make recommendations for health messaging and future behavioural interventions to improve the uptake of these health behaviours. The objectives were accomplished through 4 studies: (a) a systematic review and thematic synthesis of environmental determinants of chronic and infectious disease prevention behaviours using smoke-free policies and COVID-19 restrictions as case studies, (b) a qualitative study using online survey methods and the Theoretical Domains Framework (TDF) to explore young adults' barriers to hand hygiene during the COVID-19 pandemic, (c) a qualitative study using TDF to identify determinants of COVID-19 and influenza vaccine uptake among healthcare providers and trainees, and (d) a cross-sectional study and observational assessment of shoppers' alcohol-based hand sanitizer use, mask use, and physical distancing at various indoor community settings. Across studies, findings revealed communication and policies from government, environmental context, normative influences, and internal factors impacted individuals' health decisions. This thesis identified novel individual factors (e.g., vaccine-specific knowledge, awareness of handwashing steps), interpersonal factors (e.g., shopping alone vs. in a group), and environmental factors (e.g., automatic doors, touch-free entries) that were associated with favourable disease prevention behaviours among the groups studied. Overall, this contributes to the existing evidence for several environmental determinants of health behaviours and uniquely draws parallels between multiple behaviours, in and out of the COVID-19 context, to support intervention design. Behaviour-specific recommendations focusing on health messaging and modifications to the environmental context are provided to increase uptake of these behaviours.