RESUMEN
This qualitative study evaluates a decision aid that includes the benefits and harms of breast cancer screening and analyses women's perception of the information received and healthcare professionals' perceptions of the convenience of providing it. Seven focus groups of women aged 40-69 years (n = 39) and two groups of healthcare professionals (n = 23) were conducted in Catalonia and the Canary Islands. The focus groups consisted of guided discussions regarding decision-making about breast cancer screening, and acceptability and feasibility of the decision aid. A content analysis was performed. Women positively value receiving information regarding the benefits and harms of breast cancer screening. Several women had difficulties understanding some concepts, especially those regarding overdiagnosis. Women preferred to share the decisions on screening with healthcare professionals. The professionals noted the lack of inclusion of some harms and benefits in the decision aid, and proposed improving the clarity of the statistical information. The information on overdiagnosis generates confusion among women and controversy among professionals. Faced with the new information presented by the decision aid, the majority of women prefer shared decision-making; however, its feasibility might be limited by a lack of knowledge and attitudes of rejection from healthcare professionals.