Health inequalities over the lifecycle in Switzerland: trends before and during the COVID-19 pandemic

Health inequalities are a global public health and policy concern. They are socially produced and avoidable. Monitoring and reducing health inequalities is a priority, especially considering the role of disruptive events, such as socioeconomic impacts following recessions (and recovery efforts) and of infectious disease threats. Health inequalities are strongly associated to socioeconomic factors, like income and geographical area deprivation, and are particularly concerning for premature mortality, notably deaths occurring during the first year of life and early mortality from chronic diseases and despair. However, trends of socioeconomic inequalities in premature mortality in the 2010s and during the COVID-19 pandemic are not measured for Switzerland. Notably, it is not known whether these inequalities increased across the 2010s, and whether the pandemic exacerbated inequalities because of the infection with SARS-CoV-2 pathogen and/or because of socioeconomic disruptions associated to non-pharmaceutical mitigation policies.Our overarching objective is to measure trends of socioeconomic inequalities in premature mortality before and during the COVID-19 pandemic in Switzerland. Specifically, in Aim I we will assess trends of mortality rates by household- and area-level socioeconomic factors in the 2010s. In Aim II, we will measure the effects of the pandemic on trends of these inequalities, between 2020 and 2022. Notably, we will decompose the total effect of the pandemic into the effect related to the pathogen and the effect related to socioeconomic disruptions from non-pharmaceutical interventions. In Aim III, we will assess trends of socioeconomic inequalities in adult deaths attributed to chronic diseases and despair, before and during the pandemic. We will conduct a nation-wide population study from Swiss administrative registers. Specifically, we will use existing data for all residents from 2011 to 2022 comprising mortality and sociodemographic characteristics to measure inequalities by household or parental income and area deprivation. We will examine premature deaths over the lifecycle of infant (0-1 years) and adult (20-74 years and specific age groups) mortality. We will identify deaths attributed to SARS-CoV-2, chronic diseases and despair using a multiple causes of death approach, where each cause was reported in the death certificate as either the underlying or contributing cause of death. For Aim I, we will measure the magnitude of trends of inequalities in annual mortality rates. For Aim II, we will conduct an interrupted time series analysis to assess the magnitude of the total effect of the pandemic on inequalities by comparing mortality during the pandemic with expected mortality estimated from trends in pre-pandemic years. By contrasting observed pandemic deaths unrelated to the pathogen with these expected deaths, we will also estimate the magnitude of the specific effect attributable to socioeconomic disruptions from non-pharmaceutical interventions implemented during the pandemic. For Aim III, we will measure the same trends and effects for adult deaths specifically from chronic diseases and despair.Findings will provide strong empirical evidence about trends and magnitude of socioeconomic inequalities in premature mortality in Switzerland. The comprehensive assessment of inequalities associated to household- and area-level socioeconomic factors, and in relevant deaths related to perinatal, physical, and mental health will highlight the importance of unequal resources beyond individual responsibility. By tracing different mechanisms underpinning socioeconomic inequalities, this research will also inform response to disruptive events, such as future pandemics from an equity point of view. Finally, results will signify the importance of monitoring health inequalities over time, which may appeal to governmental agencies conducting public health surveillance and informing potential policy changes.