German mammography screening program: adherence, characteristics of (non-)participants and utilization of non-screening mammography—a longitudinal analysis

Background In Germany, all women aged 50–69 have been invited to biennial mammography screening since 2009. We aimed to assess longitudinal adherence over ten years in women aged 50 in 2009 and characterize the different adherence groups. Methods Using the German Pharmacoepidemiological Research Database (GePaRD, ~ 20% of the German population), we included women aged 50 in 2009 (baseline) with continuous health insurance coverage and without breast cancer or in-situ-carcinoma. We followed them until age 59 and categorized them according to mammography screening participation into the following groups: never, 1–2, 3–4, 5–6 times. We characterized these groups, inter alia, regarding the use of other preventive measures, non-screening mammography (i.e., mammography outside the organized screening program) and menopausal hormone therapy. Results Overall, 82,666 women were included. Of these, 27.6% never participated in the screening program, 15.1% participated 1–2 times, 31.7% participated 3–4 times and 25.6% participated regularly (5–6 times). Among regular participants, 91% utilized other preventive measures (e.g., cervical cancer screening, general health checkup) before baseline as compared to 66% among non-participants. Menopausal hormone therapy was least common among non-participants (11% vs. 18% among regular participants). Among non-participants, the proportions using ≥ 1, ≥ 2, and ≥ 3 non-screening mammographies between age 50–59 were 25%, 18%, and 15%, respectively. Conclusions Using a large cohort based on claims data, this study provides novel insights into longitudinal adherence to the mammography screening program and the use of mammography outside of the program in Germany. Between age 50–59, 57% of eligible women participated at least three times in the German mammography screening program and 28% (~ 3 in 10 women) never participated. Among non-participants, 15% had at least three non-screening mammographies during this period, indicating potential gray screening. Participants more often utilized other preventive measures as compared to non-participants. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-023-16589-5.

[b] As part of screening for female cancers, cervical cancer screening can be combined with physical breast examination.
[c] Codes for skin cancer screening were available starting in July 2008 only.

A7 Supplemental analysis regarding educational level and mammography screening participation among excluded women
In our main analysis, women without continuous insurance from 2007-2018 were excluded.The proportion of women with higher education was about 10 percentage points lower among excluded women compared to included women.We therefore conducted a supplemental analysis in order to assess whether the exclusion of women without continuous insurance affected our estimation of participation and non-participation in the mammography screening program.In this analysis, we compared all women with continuous insurance until at least 2013 (Table S3A, n=91,759, all other inclusion criteria as shown in Figure S1 were also applied but restricted to 2007-2013 where applicable) and women who were excluded in the main analysis due to lack of continuous insurance with continuous insurance until at least 2013 (i.e., a subset of all women with continuous insurance until 2013, Table S3B, n=7,616).We categorized the women according to their participation in mammography screening as described in the main analysis, except from 2009 to 2013 (Never, 1-2 times, 3 times.)Among all women with continuous insurance until at least 2013 (Table S3A), and women excluded in the main analysis due to lack of continuous insurance until 2018 (Table S3B), there are no differences in the overall distribution according to adherence group.Furthermore, in both analyses the proportion of women with higher education was similar across all adherence groups.Use of non-screening mammography 15,338 (18.6%) (18.3, 18.8) CI = confidence interval, PAP = papanicolaou test [a] Screening for colorectal cancer with the fecal occult blood test is offered from age 50 (age 55: additional offer of screening colonoscopy) and therefore not included here.[b] As part of screening for female cancers, cervical cancer screening can be combined with physical breast examination.[c] Codes for skin cancer screening were available starting in July 2008 only.[d] Any of the following: Liver disease, coronary heart disease, congestive heart failure, myocardial infarction, stroke, COPD, Hepatitis (B, C), renal insufficiency terminal), diabetes with organ damage, treated HIV, dementia, plegia.

Figure A1
Figure A1 Flowchart of selection of the study population Table A1 Distribution of women with birth year 1959 and at least one day of insurance in 2009 excluded due to lack of continuous insurance from 2007-2018 according to educational level Table A2 Utilization of other preventive measures and prevalence of comorbidities and other characteristics among women excluded due to lack of continuous insurance from 2007-2018 with information on covariates at age 48 and/or 49 Table A3 Prevalence of comorbidities and other characteristics, stratified by ten-year adherence to mammography screening Tables A4-A5 Utilization of other preventive measures and prevalence of comorbidities and other characteristics at age 55 and 59, stratified by ten-year adherence to mammography screening Tables A6 Utilization of other preventive measures and prevalence of comorbidities and other characteristics, stratified by ten-year adherence to mammography screening (one-time only vs. 1-2 times) Tables A7 Supplemental analysis regarding educational level and adherence to mammography screening Tables A8 Characterization of all included women by age and educational level Tables A9 Utilization of other preventive measures and prevalence of comorbidities and other characteristics in all included women Tables A10 Total number of non-screening mammographies, and characterization of the use of nonscreening mammographies in women with at least one non-screening mammography between age 50-59, in all included women 0) CI = confidence interval, ASS = acetylsalicylic acid, COPD = chronic obstructive pulmonary disease, HIV = human immunodeficiency virus 7 CI = confidence interval, PAP = papanicolaou test, FOBT = fecal occult blood test interval, SD = standard deviation, IQR = interquartile range

Table A1
Distribution of women with birth year 1959 and at least one day of insurance in 2009 excluded due to lack of continuous insurance from 2007-2018 according to educational level

Table A6 Utilization of other preventive measures and prevalence of comorbidities and other characteristics, stratified by ten-year adherence to mammography screening (one-time only vs. 1- 2 times) Number of participations in mammography screening
[a]Screening for colorectal cancer with the fecal occult blood test is offered from age 50 (age 55:

Table A7A
Distribution of women with continuous insurance from 2007 until at least 2013 according to five-year adherence to mammography screening and characterization of adherence groups by educational level

Table A7B
Distribution of women excluded due to lack of continuous insurance from 2007-2018 with continuous insurance from 2007 until at least 2013 according to five-year adherence to mammography screening and characterization of adherence groups by educational level