The data used in this article are based on the written part of the health module of the Integrated System of Social Surveys (POLS). POLS is an annual sample survey conducted among approximately 10 thousand persons of all ages. People living in homes and institutions are excluded from the survey. As POLS is a sample survey, the figures presented in this article are subject to a margin of error.
For the health module, about 3 thousand women aged 30 years and older are interviewed about breast cancer and breast cancer screening. 
The years 2004, 2005 and 2006 have been taken together to provide more detailed information and more reliable estimates