Are there social gradients in the occurrence of lung cancer and in the survival of lung cancer patients? Findings from an observational study using German claims data of Lower Saxony.

Objectives Only a few studies on health inequalities in terms of lung cancer are available. We examined whether social inequalities are present for the occurrence of lung cancer. Confining the analyses to patients, it was also examined whether survival over the observation period and over a standardised period of 18 months differed by occupational position and income. Methods Our findings are based on claims data from a German statutory health insurance covering 2005–2016. The database comprised N=3 163 211 women (50.7%) and men (49.3%) aged 18 years and older. Diagnoses (International Statistical Classification of Diseases and Related Health Problems 10th Revision: C34.0 to C34.9) were hospital-based, and income and occupational position were used as indicators of socioeconomic position. Analyses on social gradients were performed for employed and retired insured, but only for employed insured information on occupation and on income were available, for retired women and men only income was available. Analyses were performed by means of proportional hazard regression. Results In employed women, social gradients for the occurrence emerged for occupational position, but not for income. In men, social differences were found for both indicators. For retired insured, income gradients were found in men. Looking at overall survival, neither in women nor in men social gradients emerged. Conclusions The reported social inequalities in the occurrence of lung cancer are pointing towards social differences in smoking behaviour, exposition to hazardous occupation-related substances and differences in preventive strategies. The absence of social inequalities in survival after lung cancer suggests equality in medical treatment of the disease.