The primary aims of the study are to assess the impact of the decision aid on (1) the proportion of women who make an informed choice about whether to continue screening mammography, and (2) the participation rates of screening among women aged 70 years and older.
There are two secondary aims of the study. First, to measure the effect of the decision support tool on women's decisional conflict, anxiety, and knowledge about the issues involved in screening mammography. Second, to compare relationships between a woman's objective and perceived risk of breast cancer with her decision to continue or stop screening mammography.
Screening mammography is recommended for women aged 50-69 years but there is no recommendation for women aged 70 years and older. Therefore the decision to continue or stop having screening mammograms are largely dependent on the importance women place on the perceived benefits and harms of screening.
The decision aid is a paper workbook and worksheet containing information on the outcomes of screening mammography for women aged 70 years and older (based on a published model- Barratt et al. 2005), steps to decision making and values clarification exercise. Currently it is not known if a decision aid with information about the benefits and risks of screening mammography can help women aged 70 years and older to make an informed choice. In addition to delivering benefits to individual women in assisting them to to make an informed choice the decision aid may lead to benefits for service providers such as improved efficiency and cost-effectiveness of screening women in this age group. Thus the impact of a decision aid in the efficiency and cost-effectiveness of screening mammography is an important but untested hypothesis.
