Understanding the interactions between lifestyle and deprivation to support policy and intervention development: an overview of a mixed methods PhD.

Problem

Lifestyle factors are the strongest modifiable risk factors for non-communicable diseases (NCDs). Deprived populations have the highest clustering of unhealthy lifestyle factors and disproportionately high lifestyle-associated morality. How combinations of ‘old’ (e.g. smoking) and ‘new’ (e.g. sleep) lifestyle factors interact with each other and with socioeconomic status is largely unknown. This mixed methods PhD aims to improve understanding of the risks associated with combinations of lifestyle factors across the socioeconomic spectrum to inform policy and interventions.

Approach

There will be four work-packages (WPs):WP1) Systematic review of the literature to collate evidence for lifestyle factor combinations associated with adverse health outcomes (mortality; cardiovascular and cancer incidence) and for interactions between lifestyle factor combinations and deprivation. We will include prospective observational studies which examine the adverse health risk associated with a combination of at least three lifestyle factors. The main aim will be to identify candidate lifestyle factors to be examined in WP2. WP2) Statistical analysis of UK Biobank (>500,000 participants with self-reported lifestyle data linked to routine health outcomes) to examine how lifestyle factor combinations are associated with adverse health outcomes and how deprivation modifies those associations. Use of Cox proportional hazard models to examine risk; variable selection algorithms to identify the highest risk lifestyle factor combinations in deprived groups. WP 3) Perform similar analysis using HUNT Databank, Norway (>50,000 participants in each of 3 survey waves with detailed self-reported lifestyle and socioeconomic data linked to routine health outcomes), to assess generalisability of findings.WP 4) Evaluate how public and professionals view lifestyle factor combinations in the context of deprivation. Qualitative approach combining focus groups of members of the public from areas of deprivation and interviews with primary care nurses/physicians and public health professionals/policy makers, analysis guided by Normalisation Process Theory. This will identify the work required by individuals and groups to incorporate new evidence into policy and practice to support healthy living in deprived areas.

Findings

This PhD programme has just started. Previous work from our group has shown the disproportionate all-cause and CVD mortality from the interaction between a wide combination of unhealthy lifestyle factors and lower socioeconomic status. This highlighted the need to identify the highest risk lifestyle factor combinations. Preliminary scoping of the literature suggests there is a large body of evidence for the adverse health associated with traditional/old lifestyle factor combinations. However, there appears to be a lack both of studies that include ‘new’ lifestyle factors and of studies that assess the impact of deprivation.

Consequences

This mixed methods PhD will provide new quantitative and qualitative evidence that will develop practice and policy to support healthier living in areas of deprivation.