Socioeconomic inequalities in lung cancer - a time trend analysis with German health insurance data.

BACKGROUND Lung Cancer (LC) is one of the most prevalent cancer diseases. Due to the lack of databases which allow the combination of information on individual socioeconomic status (SES) and cancer incidence, research on social inequalities in LC among the German population is rare. The aim of the study is to analyse time trends in social inequalities in LC in Germany. METHODS The analyses are based on data of a large statutory health insurance provider. The data contain information on diagnoses, occupation and education (working age), and income (full age range) of the insurance population. Trends were analysed for two subpopulations (retirement age and working age) and stratified by sex. The analyses are based on incidence rates and proportional hazard models spanning the periods 2006-2009, 2010-2013 and 2014-2017. RESULTS Incidence rates declined in men but increased in women. For men, inequalities were strongest in terms of income and the decline in incidence was most pronounced in middle- and higher-income men. Among women at retirement age, a reversed income gradient was found which disappeared in the second period. The educational gradient among the working-age population decreased over time due to the trend towards increasing incidence among individuals with higher education. Declining gradients were also found for occupational position. CONCLUSION The findings reveal considerable inequalities in LC and that trends vary with respect to SES, sex and age. Widening income inequalities were found in the retired population, while educational and occupational inequalities tend to narrow among the working-age population.