Use of non-conventional therapies in a cohort of women with breast cancer (DAMA cohort) in Barcelona (Spain). A mixed-methods study

Introduction: The negative effects that breast cancer and its treatment have on quality of life have led many patients to turn to non-conventional therapies (NCTs). However, little is known about the type, reasons and uses of NCTs; how they relate to conventional treatments; and their effects. The goal of this study was to analyze the links between sociodemographic, family and clinical variables and the use of NCTs among women diagnosed with breast cancer between 2003 and 2013 in Barcelona's main public hospitals. Methods: A mixed-methods, cross-sectional study was carried out on women with breast cancer in a cohort of 2235 subjects. For the quantitative component, descriptive uni- and bivariate analyses (with Pearson's chi-squared test) and multivariate logistic regression were carried out. For the qualitative component, a sub-sample from the cohort was drawn to construct six discussion groups; thematic analysis was used. Results: Following diagnosis, 55.2 % of the women had used NCTs. The main reasons were to alleviate the side effects of chemotherapy, increase the body's defenses and improve quality of life. The main factors associated with use, access to practitioners and access to non-conventional treatments and products were socioeconomic factors and relapses. There were visible differences between social classes in the use of NCTs, because lower social classes suffered from social vulnerability and the lack of resources and information. Conclusions: Participants complemented conventional breast cancer therapies with a wide variety of NCTs. However, many reported that oncologists had discouraged them from using NCTs or shown little interest in understanding the NCTs their patients were using. Social inequalities in accessing NCTs were also evident.