COMPARE (COMparing treatment options for ProstAte cancer) aimed to evaluate and quantify the trade-offs patients make between different aspects of active surveillance and definitive therapy.

A Discrete Choice Experiment (DCE) tool was used to elicit patients' preferences for different treatment characteristics in 34 urology departments. Patients with localised prostate cancer completed the DCE within one week of being diagnosed and before they made treatment decisions. The DCE was pre-tested (N=5) and piloted (n=106) with patients. Patients chose their preferred treatment profile based on six characteristics: treatment type (active surveillance, focal therapy, radical therapy), return to normal activities, erectile function, urinary function, not needing more cancer treatment and 10-15 year cancer-specific survival. Different tools were designed for low-intermediate (n=468) and high-risk (n=166) patients. An error-components conditional logit model was used to estimate preferences and trade-offs between treatment characteristics.

Low-intermediate risk patients were willing to trade 6.99% absolute decrease in survival to have active surveillance over definitive therapy. They were willing to trade 0.75%, 0.46% and 0.19% absolute decrease in survival for a one-month reduction in time-to-return to normal activities, and 1% absolute improvements in urinary and sexual function, respectively. High-risk patients were willing to trade 3.10%, 1.04% and 0.41% absolute decrease in survival for a one-month reduction in time-to-return to normal activities and 1% absolute improvements in urinary and sexual function, respectively.

Patients with low-intermediate risk prostate cancer preferred active surveillance to definitive therapy. Patients of all risks were willing to trade-off cancer-specific survival for improved quality-of-life.Registration:clinicaltrials.gov Registration Identifier NCT01177865Funding:Medical Research Council (UK) (grant reference: G1002509).