This scoping review focused on answering key questions about the focus, quality and generalisability of the quantitative evidence on the determinants of adherence to social distancing measures in research during the first wave of COVID-19. The review included 84 studies. The majority of included studies were conducted in Western Europe and the USA. Many lacked theoretical input, were at risk for bias, and few were experimental in design. The most commonly coded domains of the TDF in the included studies were 'Environmental Context and Resources' (388 codes across 76 studies), 'Beliefs about Consequences' (34 codes across 21 studies), 'Emotion' (28 codes across 12 studies), and 'Social Influences' (26 codes across 16 studies). The least frequently coded TDF domains included 'Optimism' (not coded), 'Intentions' (coded once), 'Goals' (2 codes across 2 studies), 'Reinforcement' (3 codes across 2 studies), and 'Behavioural Regulation' (3 codes across 3 studies). Examining the focus of the included studies identified a lack of studies on potentially important determinants of adherence such as reinforcement, goal setting and self-monitoring. The quality of the included studies was variable and their generalisablity was threatened by their reliance on convenience samples.
Keywords: COVID-19; adherence; determinants; physical distancing; scoping review; social distancing.