Theory for the real world: behaviour change and public health

Challenge 2: Emerging epidemics

Like dengue and yellow fever, Zika virus is primarily spread by the Aedes aegypti mosquito. In 2015, a sharp rise in the number of babies born with microcephaly was linked to the emergence of Zika virus in Brazil. In response, the World Health Organization promptly declared the epidemic a Public Health Emergency of International Concern.

Guidance was issued on how to minimise the risk of contracting the virus, such as wearing long-sleeved clothing and mosquito repellent. Around the home, it was recommended that standing water was treated with larvicides or regularly removed. Pregnant women were advised to avoid travel and stay indoors at times when mosquitos are most active. It was also recommended that non-pregnant women delay pregnancy and use contraceptives during the epidemic. However, despite a series of public health campaigns, Zika rapidly spread to over 87 countries, leading to a generation of children with a series of uniquely complex and devastating disabilities.

One way to understand the perspectives of Brazilian communities affected by Zika virus is through the Health Belief Model, a framework which maps the decision-making process that a new behaviour may entail. This is because each of these behaviours can be strongly informed by a personal assessment of their convenience and cost, as well as how the behaviour may be perceived by loved ones and the wider community.

In a study that I co-authored for the London School of Hygiene & Tropical Medicine, we found that communities affected by the Zika virus epidemic felt that many of these preventive measures were not sustainable in the long term. Additionally, there was a sense that the burden of controlling the epidemic lay too much on them as individuals – especially women. For these reasons, the worldwide epidemic-preparedness community has predicted we have a high risk of Zika virus returning – in addition to outbreaks of similar neglected tropical diseases.

Challenge 3: Increasing participation in cancer screening programmes

There is strong evidence that lung cancer screening programmes can save lives by detecting the cancer earlier. To be successful, a national screening programme must draw in people at the highest risk of lung cancer. The challenge is to engage them.

Behaviour change frameworks can help us to understand why people at greater risk of lung cancer are sometimes less likely to access free screening appointments. Some experts have used the Capability, Opportunity, Motivation and Behaviour (COM-B) model to break down the underlying conditions that need to be in place for behaviour change. For example, an individual might not consider engaging in a prevention service like screening if they don’t have enough time or a means of transport to get there.

The model demonstrates that even when interventions are put in place to improve access to the physical and financial resources needed for screening, if the psychological and social needs are also not met, uptake may remain low. An example is stigma around lung cancer and smoking, which may cause some people to feel ashamed about their invitation to a screening programme. In this case, some interventions that have been explored include personalised invitations from their doctor, text or postal appointment reminders, and health campaigns to reframe and normalise screening as free ‘servicing’ for their lungs.

Applying the right theoretical framework enables public health professionals to answer questions such as: where can we develop an intervention to lead to population-level behaviour change? What works and what doesn’t? Can the evidence for each component be mapped and measured? And which area should be a priority for government investment?

The opinions expressed in this blog are those of the author and do not necessarily represent the views of The Health Policy Partnership.