What did we learn about changing behaviour during the COVID-19 pandemic? A systematic review of interventions to change hand hygiene and mask use behaviour

Background: behaviour change interventions were central in the COVID-19 response and are vital for strengthening pandemic preparedness and resilience. To be effective, interventions must target specific behavioural determinants, but determinants are complex and multifaceted and there is a gap in robust, theory driven evidence on which behavioural determinants are most effective at changing mask usage and hand hygiene behaviour. Purpose: to map available evidence on the types of hand hygiene and mask usage behaviour change interventions conducted during the COVID-19 pandemic and assess their effectiveness, feasibility and acceptability. Methods: we conducted a systematic review, searching four peer-reviewed databases for terms related to COVID19, targeted behaviours (hand hygiene and mask usage) and interventions. Eligible studies were those which focused on adults or children in naturalistic, non-experimental settings; reported on an intervention designed to change hand hygiene and or mask usage to reduce COVID-19 transmission; provided clear outcome measures, including through self-report, proxy indicators or observation. Studies were excluded if they were purely qualitative, opinion pieces or based on secondary data alone; focused on health workers; measured intended rather than enacted behaviour; were conducted in laboratory or health care-based settings; involved infants; were published before the 11th of March 2020 (when COVID-19 was declared a pandemic) and published in a language other than English. There were no geographical limits set. Descriptive summaries were produced and the quality of evidence and reporting was evaluated. Studies were divided into three sub-groups according to the behaviour targeted and behaviour change techniques (BCTs) were mapped. Effect estimates were summarised and the relationship between BCTs and effect was explored. Feasibility and acceptability was summarised where reported. Due to the heterogeneity of studies included, meta-analysis could not be conducted. Findings: sixteen citations met the criteria, with sub-studies (two citations including multiple studies) totalling nineteen eligible studies. The majority were randomised controlled trials which targeted hand hygiene only and were conducted in high income nations, with none conducted in crisis settings. Due to the constraints of the pandemic, many interventions were delivered online. The quality of studies was low, with the majority demonstrating a medium risk of bias (Likert scale: low, medium, high). Whilst acceptability and feasibility was good, both were rarely evaluated. 'Natural consequences' was the most commonly used BCT group. Fourteen of the studies elicited positive or potentially positive effects in at least one intervention arm and/or targeted behaviour. Effective interventions typically targeted multiple individual BCTs, including 'Instruction on how to perform a behaviour', 'Information about health consequences', and group 'Reward and threat', through repeated engagement over a sustained period of time. Conclusion: there is a substantial knowledge gap, particularly in low resource and crisis settings, and available evidence is of low quality. We must address these gaps to enable evidence-based practice and strengthen pandemic preparedness and resilience. Future research should include another systematic review which includes grey literature and different languages, as well as more robust evaluations which use implementation research to explore the impact of multiple BCTs in low resource and crisis settings. Evaluations should include assessments of acceptability, practicability, affordability and equity.