Evaluation of a Shared Decision Making Program for Women Suspected to Have a Genetic Predisposition to Breast Cancer

Background. Women suspected to have a genetic predisposition to breast cancer face the difficult choice between regular breast cancer screening and prophylactic mastec tomy. The authors developed a shared decision making program (SDMP) to support this decision. Objectives. To evaluate the SDMP in terms of practicality, beneficial effects, and patient satisfaction. Design. A one-group pretest-posttest design was used. Measures. Decision uncertainty, decision burden, subjective knowledge, and risk comprehension were assessed before and after the SDMP. Additional measures were obtained for concepts related to breast cancer concern, desire to participate in the program, satisfaction, program acceptability, and emotional reaction to the program information. Results. Seventy-two women, most of whom were awaiting the genetic test results, participated. Decision uncertainty (effect size d = 0.37) and decision bur den (d= 0.41) were reduced by the SDMP. Subjective knowledge (averaged d= 0.94) and risk comprehension were improved. The women were satisfied with the SDMP and found its rationale acceptable. Women who had strong emotional reactions to the information benefited less from the SDMP, whereas women with strong desires to participate in the decision benefited more. Conclusions. There is a need to give pa tients more information, especially about prophylactic mastectomy and among gene carriers. Beneficial effects were observed irrespective of whether genetic status was known, suggesting that information concerning treatment options should be made available as soon as DNA testing begins. The better psychological outcomes of women with stronger desires to participate may arise because the desire to participate is char acteristic of emotional stability. Key words: shared decision making; breast cancer; genetic predisposition; patient participation; patient satisfaction. (Med Decis Making 1999; 19:230-241)