Inequalities in behavioural risk factor prevalence between five post-war generational cohorts of working age, England

Background and objectives: Long-term trends in health risk factor prevalence, and in inequalities, are often summarised using age-standardised point prevalence to allow for age distribution changes over time and between groups. Policies to effectively promote health require the decomposition of social change into its age-period-cohort components. As a first step, we provide a descriptive age-cohort analysis to identify patterns of generational change in key behavioural risk factors between and within post-war cohorts of working age in England. Data: Cross-sectional Health Survey for England data for participants aged 25-60 years was pooled between 1994-2019 (n=153,172) to construct five decennial cohorts (1940s, 1950s, 1960s, 1970s, 1980s). Socioeconomic status was classified by neighbourhood deprivation quintiles using the Index of Multiple Deprivation. Five behavioural risk factors were analysed: cigarette smoking (current- and heavy-smoking); alcohol consumption (frequency and heavy drinking); obesity; meeting recommended levels of physical activity and fruit and vegetables consumption. Methods: Sex-specific analyses were conducted. Log-binomial regression models quantified the magnitude and direction of change in (i) prevalence ratios (PRs) between cohorts adjusting for age and deprivation and (ii) deprivation-specific PRs within- and between-cohorts to examine changes in absolute and relative inequalities between generations. Results: In more recent cohorts, decreases in prevalence, independent of age and deprivation, were observed for current smoking, frequency of alcohol consumption and heavy drinking, resulting in decreasing absolute inequalities. However, obesity levels, particularly among females, reached their highest levels in the youngest 1980s cohort. Relative inequalities in current smoking (most- versus least-deprived quintiles) peaked in the 1950s cohort (Males: PR 2.79 (95% CI: 2.57-3.04); Females: PR 2.81; 95% CI: 2.60-3.05)), decreased in the 1960s cohort (Males: PR 2.00 (95% CI: 1.70-2.34); Females: PR 2.58 (95% CI: 2.40-2.77)), and remained stable thereafter. Inequalities in heavy smoking persisted over time among current smokers. Higher obesity levels in the most- versus least-deprived quintiles were generally persistent across all five cohorts, albeit with some suggestion of widening inequalities in the younger- versus older-cohorts in females (1940s cohort: PR 1.55 (95% CI: 1.40-1.72); 1960s cohort: PR 1.87 (95% CI: 1.73-2.01)). This pattern was also observed for mean body mass index (BMI). For heavy drinking, relative inequality remained stable. Relative inequalities in fruit and vegetable consumption were lower in more recent cohorts. Physical activity levels were similar across cohorts, with little evidence of inequalities. Conclusion: Our analysis of generational change reveals credible signals of behavioural risk factor changes in levels and in inequalities over successive post-war cohorts of working age. ### Competing Interest Statement MB has support from Legal and General Assurance Society Limited for the submitted work; SS has no relationship with Legal and General Assurance Society Limited in the submitted work or in the previous 3 years. The authors have no other competing interests. ### Funding Statement MB is honorary research staff at UCL, funded by Legal & General Assurance Society Limited (L&G) as part of its wider research collaboration with UCL on longevity research. SS received no specific funding for this work. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Data are available in a public, open access repository. The HSE datasets generated and analysed during the current study (age banding for participants) are available via the UK Data Service (UKDS: https://ukdataservice.ac.uk/), subject to their end user license agreement. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes UK Data Service (UKDS: https://ukdataservice.ac.uk/), subject to their end user license agreement.