gms | German Medical Science

Introduction: Mammography screening programmes (MSP) aim to reduce breast cancer mortality by detecting tumours at earlier stages. In Germany, women aged between 50 and 69 are eligible for an examination every two years. Participation in the program is, however, lower than European guidelines demand [1]. We evaluated factors associated with (repeated) participation using a large population-based study.

Methods: Using baseline (i.e. cross-sectional) data from the German National Cohort Study (NAKO) we included women aged 50-69 at recruitment (2014-2019) who provided information on participation in the MSP. We used age-adjusted univariable logistic regression models to identify factors associated with participation, and then conducted a principal component analysis (PCA) to derive meaningful dimensions of participation behaviour. The resulting components and specific factors not included in the PCA were then included in multivariable regression models to evaluate the proportion of variance captured by easily measurable variables.

Results: Of 48,063 included women, 14.6% had never participated in the MSP, 35.2% had participated once, and 50.2% had participated several times. Having had at least one breast palpation was the single largest factor associated with participation in the MSP (OR: 9.6, 95%CI: 8.9-10.3). The PCA yielded three factors with a cumulative variance of 33.9%: “use of preventive health measures” (RC1), “lifestyle factors” (RC2) and “socioeconomic status”(RC3), with maternal family history of breast cancer being the only included factor not assigned to a main component. The multivariable model of the three components (RC1: OR:2.2, 95%CI: 2.1-2.4; RC2: OR:1,4, 95%CI:1.3-1.5; RC3: OR:0.8, 95%CI:0.7-0.8) showed a Nagelkerke R² of 19.6%. Adding age, which is then not significant, and family history (OR:1.7, 95%CI:1.3-2.3) to the three factors increased the Nagelkerke R² to 19.9%.

Conclusions: In this large-scale population-based analysis we identified among NAKO participants three defined dimensions of (non-)participation in the German MSP. Although our study has some limitations, such as a possible misclassification of participation in the MSP, e.g. due to a lack of differentiation between grey screening and MSP screening, our results can be employed to enhance participation through the implementation of targeted measures, such as the involvement of general practitioners and gynaecologists, which is also recommended in the literature (e.g. [2]).

The authors declare that they have no competing interests.

The authors declare that a positive ethics committee vote has been obtained.