Adherence to public health measures during the COVID-19 pandemic: the pivotal role of behavioural science

The role of human behaviour in COVID-19 prevention

Human behaviour is crucial for the successful handling of the pandemic at each level of prevention. At the primary prevention level, which aims to target a condition before it has evolved [20], behavioural science can help to understand and promote adherence to protective behaviours such as hygiene and physical distancing [21]. Furthermore, it can give insights into vaccine hesitancy, barriers towards the uptake of a vaccine and the reduction of both hesitancy and barriers [22]. At the secondary prevention level, which aims at early detection and intervention of a condition [23], it can contribute to adherence with testing, tracing (e.g., the use of the COVID-19 app), quarantine or self-isolation [24]. At the tertiary prevention level, which aims to alleviate symptoms, prevent the progression of a disease and subsequent disability after initial diagnosis [25], human behaviour is key to promoting rehabilitation through treatment adherence, and prevention of multimorbidity, for example, by self-management of mental health. In addition to population health, human behaviour is also key in maintaining health services, for example, by maintaining the health and well-being of hospital staff [26].

For most of us, the majority of COVID-19 preventive measures were new behaviours, disrupting our lifelong habits. For some, it might be difficult to maintain preventive behaviours for the extended period required [27-30]. The majority of the population seems to be willing to adhere to public health interventions, but actual adherence is much less common (also referred to as intention-behaviour gap) [14, 31-33]. Furthermore, not all interventions are equally accepted or complied with [34, 35]. In Europe, one example of relatively low acceptance is the use of mobile data for contact tracing [35]. In Switzerland in particular, almost 60% of the population (which equals to approx. 5.14 million people) expressed the intention to install the SwissCovid App, but to date only around 1.89 million apps are active [14, 36]. Another example might be the uptake of a vaccine, as vaccine hesitancy is high in Europe [37]. Even with a safe vaccine available and despite the public’s intention to be vaccinated, the intention-behaviour gap indicates that uptake might not be as high as might be hoped for [22, 38-40]. Currently in Switzerland, around 41% are willing to get vaccinated immediately and unconditionally, 24% are unwilling to get vaccinated and the rest is undecided [2]. Interestingly, around 55% of the population in Geneva agreed that vaccination should be mandatory [41].

How behavioural science can contribute to COVID-19 prevention

As human behaviour is key to successfully managing a pandemic, behavioural sciences provides pivotal insights into how to promote behaviour change (adoption and maintenance) at all levels of prevention. Health psychology and behavioural medicine, for example, aim to understand behavioural factors of illness prevention, health promotion and rehabilitation [42]. Health psychologists study psychosocial predictors that guide health-related human behaviour. Based on these models, they develop and evaluate evidence-based preventive interventions. Predictors of health-related behaviours (e.g., adherence to preventive measures) specified in behaviour change theory go beyond well-known and targeted factors such as risk perception. One evidence-based behaviour change model, the health action process approach (HAPA model) [43, 44], for example, defines risk perception as a basic, but often insufficient, predictor of health behaviour. To understand and promote behaviour, the HAPA model specifies further motivational and volitional processes along with risk perception. At the motivational stage, a person forms a behavioural intention (a decision to change or maintain their behaviour), which is determined by the person’s risk perception, their outcome expectancies (what will happen as an outcome of the behaviour) and their self-efficacy (the confidence in one’s ability to perform the behaviour). A motivated person will then be more likely implement the intended behaviour when they have detailed action and coping plans, and closely monitor their behavioural change or maintenance. These factors distinguish persons who adhere to protective pandemic measures from those who do not [45]. Targeting these behavioural determinants is a highly promising way to promote adherence. Yet public health communication is often limited to promoting risk perception alone, often with little effect.

The way forward: recommendations

We call for a systematic inclusion of behavioural scientists in the Swiss Science Task Force or other government advisory boards. New evidence regarding, for example, predictors of adherence to COVID-19 preventive measures emerge daily [46]. To best promote adherence, public information needs to consider these insights. It is not within the scope of this brief article to summarise this growing body of evidence exhaustively. However, to exemplify how evidence from behavioural science can inform long-term COVID-19 policy considerations, we conclude with some recommendations and examples for practice:

1. Communicate via a trustworthy source in a relatable way. Public trust in government is important [14, 34, 47-50]. For example, humans have difficulty in understanding probabilities (percentages). Use natural frequencies instead [51]: one out of two people report tiredness or headache after the Pfizer-BioNTec COVID-19 vaccine [52]. A good example of communicating the transmission of aerosols was presented in the newspaper El País [53]. The newspaper painted the transmission of the virus via aerosols in three relatable, every day scenarios (bar, room or classroom) based on safety measures used (wearing of masks, ventilating space) and length of exposure. The article used easy-to-understand animations, graphics and language. Another example as a source of misunderstanding is exponential growth, a concept difficult for humans to understand. It is commonly underestimated, potentially leading to lower perceived benefit of public health interventions. However, communicating doubling times instead of growth rates and presenting data visualisation helps: every three days, the number of infected people doubles [54, 55].
2. Unify messages across sources while communicating that new evidence might be associated with uncertainty and can change as we learn more [56]. For example, the basic reproduction number R. Media and government might fixate too much on it, disregarding the importance of other measures such as trends in numbers of new infections. R is an imprecise measure based on assumptions, does not capture the current state of the pandemic [57] and should be reported as such.
3. Address concerns regarding public health interventions [35]. Adapt these messages according to changing concerns. For example in Switzerland, the SRG Corona-Monitor, currently in its sixth edition, offers important insights into public concerns regarding a variety of interventions and the well-being of the population [2]. Worries regarding social isolation have grown and could be addressed by promoting information on mental well-being [58, 59].
4. Promote population-based health literacy and knowledge about the importance of concrete interventions [33, 60]. For example, health literacy and knowledge can be actively promoted via public health campaigns such as the human immunodeficiency virus (HIV) campaigns in the 1990s in Switzerland and other countries [61].
5. Repeat public health messages and repeat why public health interventions are important [62]. In psychology, there is a well-known mere-exposure effect [63]. It means that repetition leads to familiarity, which leads to preference. Therefore, repeating COVID-19 preventive measures is likely to increase adherence.
6. Reinforce positive, health-promoting norms via models from the community [16]. People with a large outreach in social networks are often labelled as “influencers”. Given the number of social contacts, influencers are more likely than others to have witnessed or experienced new developments regarding the pandemic. Compared with anonymous public messages, reports of influencers regarding their personal behaviour modification are likely to have a more substantial impact on the behaviour of their followers on social networks.
7. Enhance the population’s self-efficacy and personal control [11, 56, 64]. Self-efficacy can be promoted by facilitating mastery experience, for example, through guiding people to change their protective behaviour step-by-step, by learning from role models, or persuasion [65]. Self-efficacy plays a pivotal role when the content of the message evokes fear in the addressees, which can be the case when information regarding contagious diseases is distributed. In instances of low self-efficacy and a high level of fear, the reaction is more likely to be defensive and thus not compliant with public health guidelines [16].
8. Use the term “physical distancing” instead of “social distancing” as the latter might imply cutting meaningful interactions completely [16]. This messaging helps emphasise that, although physical distance is necessary for slowing the pandemic, people can remain socially and emotionally connected to their loved ones [66]. Social interaction is important for our mental health and well-being, helping people to regulate emotions, cope with stress and remain resilient during difficult times [16]. This resilience is necessary to comply with the preventive measures and sustain the required behaviour change [67]. Fortunately, nowadays a range of technologies to stay socially connected exist (e.g., social networks, video and phone calls, emails and messaging), which can help to reduce the harmful effects of isolation during the COVID-19 pandemic [68].

The majority of the permanent residents living in Switzerland have never before faced such collective challenges as during this pandemic. Outlined evidence is largely based on the early stages of the pandemic, earlier epidemics in other parts of the world, or generic health behaviour change research. Changes in peoples’ perception and behaviour, and factors associated with these changes during the second, longer-lasting wave of the pandemic, need further research. For future responses to this pandemic, as well as responses to future public health challenges in general, it will be crucial that behavioural science disciplines are more comprehensively integrated in advisory boards, to ensure most effective response.