Protocol of the COVID-19 Health and Adherence Research in Scotland (CHARIS) study: understanding changes in adherence to transmission-reducing behaviours, mental and general health, in repeated cross-sectional representative survey of the Scottish population

Introduction: COVID-19 has unprecedented consequences on population health, with governments worldwide issuing stringent public health directives. In the absence of a vaccine, a key way to control the pandemic is through behavioural change: people adhering to transmission-reducing behaviours (TRBs), such as physical distancing, hand washing and wearing face covering. Non-adherence may be explained by theories of how people think about the illness (the common-sense model of self-regulation) and/or how they think about the TRBs (social cognition theory and protection motivation theory). In addition, outbreaks of infectious diseases and the measures employed to curb them are likely to have detrimental effects on people's mental and general health. Therefore, in representative repeated surveys, we will apply behavioural theories to model adherence to TRBs and the effects on mental and general health in the Scottish population from June to November 2020, following the initial outbreak of COVID-19.

Methods and analysis: Repeated 20 min structured telephone surveys will be conducted with nationally representative random samples of 500 adults in Scotland. The first 6 weeks the survey will be conducted weekly, thereafter fortnightly, for a total of 14 waves (total n=7000). Ipsos MORI will recruit participants through random digit dialling. The core survey will measure the primary outcomes of adherence to TRBs, mental and general health, and explanatory variables from the theories. Further questions will be added, enabling more detailed measurement of constructs in the core survey, additional themes and questions that align with the evolving pandemic.

Ethics and dissemination: Ethical approval for this study was granted by the Life Sciences and Medicine College Ethics Review Board (CERB) at the University of Aberdeen (CERB/2020/5/1942). Results will be made available to policy makers, funders, interested lay people and other researchers through weekly reports and three bimonthly bulletins placed on the CHARIS website and advertised through social media.