The BREAST-Q Utility Module: A New Preference-Based Measure For Breast Cancer

Abstract

Preference-based measures (PBMs) of health-related quality of life (HRQOL) are used to generate health state utility values (HUVs). HUVs are then used to calculate quality-adjusted life-years (QALYs) for use in cost-effectiveness analyses (CEAs) of healthcare interventions. Although generic PBMs have been commonly used to estimate QALYs in cancer, they omit aspects of HRQOL that matter to women with breast cancer. This thesis begins by setting the stage for the development of a new PBM (Chapter 1). In Chapter 2, the results of a systematic literature review of published HUVs in breast cancer are presented. This review highlighted the heterogeneity in the study population and utility estimation methods in the literature and found that most studies use EQ-5D, a generic PBM, to assess HUVs in breast cancer. No breast cancer-specific PBM exists. Consequently, this thesis delineates the development of the descriptive system of a new breast cancer-specific PBM called the BREAST-Q Utility module. The development of the Utility module adhered to best practice guidelines for the development and validation of patient-reported outcome instruments; the protocol is included in Chapter 3. In Chapter 4, the results of the mixed methods, international study to develop the descriptive system of the Utility module are presented. Semi-structured interviews were conducted with 57 women diagnosed with breast cancer using an interpretive description approach. At the end of the interview, the women were asked to list their top five HRQOL concerns and rate the importance of each item on the BREAST-Q. The data were analyzed and used to develop the preliminary Utility module, which was refined with feedback from women with breast cancer (n=9) and a multidisciplinary group of experts (n=23). In the final chapter, the role of the BREAST-Q Utility module in CEAs of breast cancer interventions is described, and the strengths and limitations of the work are reviewed.