Sexually transmitted infection prevention behaviours: Health impact, prevalence, correlates, and interventions.

Sexually transmitted infections (STIs) remain a major public health threat, disproportionately affecting young people, and men who have sex with men. In this narrative review of the current state of behavioural science research on STI prevention, we consider the definition, health impacts, correlates and determinants, and interventions to promote STI prevention behaviour. Research on STI prevention behaviour has extended from a focus on abstinence, partner reduction and condom use, to also include novel preventive behaviours, notably treatment-as-prevention, pre-exposure prophylaxis (i.e., the preventive use of medicines by uninfected people), and vaccination for some STIs. Social-cognitive factors specified by, for instance the theory of planned behaviour, are critical proximal determinants of STI prevention behaviours, and related interventions can effectively promote STI prevention behaviours. Social-ecological perspectives highlight that individual-level determinants are embedded in more distal environmental influences, with social stigma especially affecting STI prevention behaviours and requiring effective intervention. Further to providing a major domain of application, STI prevention also poses critical challenges and opportunities for health psychology theory and research. We identify a need for health behaviour theory that addresses the processes linking multiple levels of influence on behaviour and provides practical guidance for multi-level behaviour change interventions adapted to specific contexts.