Using discrete choice experiments to understand patient values and preferences for prostate and colorectal cancer screening in the US and Australia

High quality cancer screening decision-making processes should incorporate patient values and preferences. Decision aids are effective for informing patients about the benefits and downsides of screening tests, but the best way of eliciting and incorporating patient values and preferences within decision aids is unclear. We propose to compare three different techniques for eliciting patient values: 1) implicitly, through use of a “balance sheet”; 2) explicitly, using a rating and ranking task; and 3) explicitly, using discrete choice experiments. We will study these three different techniques for two distinct screening decisions: the decision whether or not to have prostate specific antigen (PSA) screening and the decision about which type of colorectal cancer (CRC) screening test to have (fecal occult blood testing, sigmoidoscopy, colonoscopy, or CT colonography). We will examine these questions in nationally representative samples from the US and Australia to study whether values and preferences elicited by these methods differ across countries. We will recruit 1,920 average-risk adults ages 50-70 (960 US, 960 Australia) from online registries maintained by a survey research organization. Of the 1,920 participants, 120 participants will be pre-test subjects and 1,800 participants will be subjects in the actual study. Each participant will be asked to complete online questionnaires before and after being exposed to web-based information about the screening test and one of the three randomly assigned values elicitation techniques. Main outcomes will be post-task differences between groups in knowledge, perceived most important screening test attribute, values clarity, intent to undergo screening, and values-treatment choice concordance. We will use the results for an NCI R01 proposal and to guide the development of future decision aids.

Principal Investigator: Michael Pignone, MD, MPH
Funding: Lineberger University Cancer Research Fund (UNC-CH)
Total Project Period: 07/01/2010 – 06/30/2012