Patient choice in colorectal cancer treatment - A systematic review and narrative synthesis of attribute-based stated preference studies

Aim The global burden of colorectal cancer (CRC) is set to increase by 60% by 2030. An aging population and increasing treatment complexity add difficulties for patients and clinicians in CRC management. Patient preferences can be investigated using attribute-based stated preference (AbSP) techniques to explore trade-offs between different treatments. These techniques include discrete-choice experiments (DCEs), conjoint analysis and time-trade off (TTO) methods. This systematic review with a narrative synthesis aimed to determine the use and design of AbSP studies in CRC treatment and to identify patient choice themes. Methods The searches were performed using MEDLINE, Embase, PsycInfo and Cochrane Library in March 2021. All manuscripts featuring the use of AbSP techniques in CRC treatment were included. Data synthesis was performed using a narrative approach. Results The search strategy returned 271 articles. Eighteen AbSP studies were included featuring 1890 patients and 296 clinicians. AbSP techniques compromised DCE (38.9%, n = 7), TTO (38.9%, n = 7) and conjoint analysis (22.2%, n = 4). Eleven studies (61.1%) involved piloting of tasks and the average task completion rate was 75%. CRC treatments included chemotherapy (33%, n = 6), combined treatments (33%, n = 6), surgery (17%, n = 3), targeted therapy (11%, n = 2) and radiotherapy (6%, n = 1). The most examined domain was physical health, investigated with 49 (59.8%) attributes. Conclusions Life expectancy was the main attribute in chemotherapy treatment. With surgery, patients were willing to trade life-expectancy to avoid adverse outcomes or a permanent stoma. Communication skills, treatment cost, and clinicians' views were important attributes for patients in cancer services. Further research in the elderly population, and other quality of life domains, are needed to deliver patient-centred CRC care.