Trends in the use of mammography for early breast cancer detection in Switzerland: Swiss Health Surveys 2007 and 2012.

AIMS: Breast cancer is the most common cancer in women worldwide. We assessed changes in the use of breast cancer screening 2007-2012 in Switzerland, and associations with socioeconomic and health-related determinants.

METHODS: We used the nationwide and representative data from the Swiss Health Surveys 2007 and 2012. We analysed the self-reported use of mammography in the last 12 months (proportion of population) among women aged 40-79 years, and opportunistic (without clinical symptoms, initiated by the woman or a physician) and programmatic screening mammography (as part of a systematic screening programme). We performed multivariate logistic regression analyses (presented as adjusted odds ratios, aORs).

RESULTS: The use of any mammography in the last 12 months declined from 19.1% (95% confidence interval [CI] 17.7-20.5%) in 2007 to 11.7% (95% CI 10.7-12.6%) in 2012. This decline was more pronounced in regions with a long-standing or no cantonal breast cancer screening programme (aOR 0.5, 95% CI 0.4-0.6, and aOR 0.5, 95% CI 0.4-0.6, respectively), but remained relatively stable in regions with a recently introduced programme (aOR 0.9, 95% CI 0.6-1.3, p-value from test for interaction 0.01). Opportunistic screening dropped from 12.0% (95% CI 10.9-13.2%) in 2007 to 6.2% (95% CI 5.5-6.9%; p <0.001) in 2012, whereas the use of programmatic mammography remained stable at 3.1% (95% CI 2.6-3.7%). Use of any mammography was higher in women aged 50-69 years, residing in a region with a systematic screening programme in place, and women having a private hospital stay insurance, but was not associated with education level and non-Swiss citizenship.

CONCLUSIONS: Overall attendance of breast cancer screening is low in Switzerland and decreased between 2007 and 2012, despite expanding cantonal mammography screening programmes. Many factors may have contributed to this decline, including the ongoing scientific and public debates on the value of breast cancer screening.