Autonomy matters: the role of autonomous motivation in healthcare professionals' decisions to vaccinate against seasonal influenza

Influenza (flu) is a highly infectious respiratory virus, posing a serious and increased risk for health complications and premature death. To protect against the spread of the virus, 'at-risk' groups such as Healthcare Professionals should be vaccinated. Ensuring improved immunity within this target group may help to reduce the risk of nosocomial transmission to patients (Goins et al., 2011). Yet, despite annual flu campaigns, the recommended 75% vaccine coverage rate remains a challenge. Typically, psychological frameworks such as the health belief model and the theory of planned behaviour are used to understand, predict and explain psychological, social and environmental factors of vaccination decisions. However, research often only goes as far as to predict vaccination uptake, and there is a need for an increase in scientifically-led theory-based interventions (Corace et al., 2016). This thesis applies the theoretical lens of self-determination theory (SDT), a general theory of human motivation (Ryan & Deci, 2000), to investigate the role of autonomy in Healthcare Professionals' decisions to get vaccinated against the flu. In addition, it seeks to understand how encouraging an autonomous decision may impact behavioural intentions to receive the flu vaccination. Its contribution begins with a systematic review identifying and assessing the effectiveness of existing health-related behavioural interventions rooted in SDT, highlighting that autonomy is an important factor for positive behavioural outcomes and sustained behaviour change. It provides insight into strategies and measures for the development of behavioural interventions, contrasting environments which support choice or force change. Based on these findings, four cross-sectional survey studies are reported, which all contributed to the development of a psychometric scale measuring Healthcare Professionals' flu vaccine motivations. The scale was distinct from, and contributed over and beyond, other psychosocial measures of flu vaccination behaviour and can be used to understand the motivation of both vaccine acceptors and vaccine deniers. Findings support the recommendation that assessing autonomous regulation is essential for understanding the psychological drivers of vaccine uptake (Denman et al., 2016), adding that additional regulations of autonomy, such as introjection (guilt avoidance) and external control are also important for assessing healthcare professionals' flu vaccine decisions. The final contribution of the thesis, in response to the increased need for scientifically led theory-based interventions, includes a pilot and an experimental study which developed and tested different communication styles aimed at promoting healthcare professionals' vaccine uptake. Reported findings reveal that communication messages supporting the need for autonomy, compared to messages using high controlling language, reduce the threat to freedom of choice. Autonomy-supportive messages have a positive impact on the change in behavioural intentions to vaccinate against the flu when autonomous and introjection regulations are low. Thus, the present thesis provides a new and important avenue to understand the motivation driving healthcare professionals' flu vaccine decisions, and it provides theoretically driven foundations for a future behaviour change intervention, incorporating autonomy-supportive communication styles.