Assessing and Explaining Geographic Variations in Mammography Screening Participation and Breast Cancer Incidence

Jonas Czwikla; Iris Urbschat; Joachim Kieschke; Frank Schüssler; Ingo Langner; Falk Hoffmann

doi:10.3389/fonc.2019.00909

Assessing and Explaining Geographic Variations in Mammography Screening Participation and Breast Cancer Incidence

Front Oncol. 2019 Sep 18:9:909. doi: 10.3389/fonc.2019.00909. eCollection 2019.

Authors

Jonas Czwikla^{1

2

3}, Iris Urbschat⁴, Joachim Kieschke⁴, Frank Schüssler⁵, Ingo Langner⁶, Falk Hoffmann¹

Affiliations

¹ Department of Health Services Research, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany.
² Department of Health, Long-Term Care and Pensions, SOCIUM Research Center on Inequality and Social Policy, University of Bremen, Bremen, Germany.
³ High-Profile Area of Health Sciences, University of Bremen, Bremen, Germany.
⁴ Epidemiological Cancer Registry of Lower Saxony, Registry Unit Oldenburg, Oldenburg, Germany.
⁵ Institute for Applied Photogrammetry and Geoinformatics, Jade University of Applied Sciences Wilhelmshaven/Oldenburg/Elsfleth, Oldenburg, Germany.
⁶ Department of Clinical Epidemiology, Leibniz Institute for Prevention Research and Epidemiology - BIPS, Bremen, Germany.

Abstract

Investigating geographic variations in mammography screening participation and breast cancer incidence help improve prevention strategies to reduce the burden of breast cancer. This study examined the suitability of health insurance claims data for assessing and explaining geographic variations in mammography screening participation and breast cancer incidence at the district level. Based on screening unit data (1,181,212 mammography screening events), cancer registry data (13,241 incident breast cancer cases) and claims data (147,325 mammography screening events; 1,778 incident breast cancer cases), screening unit and claims-based standardized participation ratios (SPR) of mammography screening as well as cancer registry and claims-based standardized incidence ratios (SIR) of breast cancer between 2011 and 2014 were estimated for the 46 districts of the German federal state of Lower Saxony. Bland-Altman analyses were performed to benchmark claims-based SPR and SIR against screening unit and cancer registry data. Determinants of district-level variations were investigated at the individual and contextual level using claims-based multilevel logistic regression analysis. In claims and benchmark data, SPR showed considerable variations and SIR hardly any. Claims-based estimates were between 0.13 below and 0.14 above (SPR), and between 0.36 below and 0.36 above (SIR) the benchmark. Given the limited suitability of health insurance claims data for assessing geographic variations in breast cancer incidence, only mammography screening participation was investigated in the multilevel analysis. At the individual level, 10 of 31 Elixhauser comorbidities were negatively and 11 positively associated with mammography screening participation. Age and comorbidities did not contribute to the explanation of geographic variations. At the contextual level, unemployment rate was negatively and the proportion of employees with an academic degree positively associated with mammography screening participation. Unemployment, income, education, foreign population and type of district explained 58.5% of geographic variations. Future studies should combine health insurance claims data with individual data on socioeconomic characteristics, lifestyle factors, psychological factors, quality of life and health literacy as well as contextual data on socioeconomic characteristics and accessibility of mammography screening. This would allow a comprehensive investigation of geographic variations in mammography screening participation and help to further improve prevention strategies for reducing the burden of breast cancer.

Keywords: breast cancer; cancer registry data; geographic variations; health insurance claims data; incidence; mammography screening; participation; screening unit data.