Identifying relevant comparators in a prostate cancer screening cost-effectiveness model: Gaining consensus using a modified-Delphi approach


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Edna Keeney, Howard Thom, Emma Turner, Richard Martin, Sabina Sanghera



Screening provides one of the best methods of early detection and prevention of cancer. However, the optimal screening pathway can be unclear, given constantly evolving evidence on tests, screening intervals and population targets. Cost-effectiveness models can provide recommendations on the most cost-effective screening strategy, but a multitude of possible pathways and disagreement amongst experts results in challenges deciding which to compare. In prostate cancer screening, recent developments in risk-stratification, early-detection biomarkers, and improved diagnostic technologies make this particularly difficult. We report a modified-Delphi approach to identify the most relevant strategies for comparison.


The Delphi technique is a method of gaining consensus from a group of experts through the collection of informed judgments over multiple iterations. This application involved two rounds of anonymous online questionnaires to identify aspects of prostate cancer screening that international researchers, clinicians and decision-makers felt important to consider. In round 1, respondents indicated their preferred screening strategy (including no screening) through a series of multiple-choice questions. The responses informed a set of 13 consensus statements, accompanied by a summary of group feedback from the previous round, which respondents ranked their agreement with on a 9-point Likert scale (round 2). Consensus was considered reached if >70% of participants indicated agreement and <15% indicated disagreement.


Twenty participants of 27 invitees completed round 1 and 17 of 20 completed round 2. Group consensus was to compare six strategies: no formal screening (current practice), age-based screening, screening only higher-risk men, using shorter screening intervals for higher than lower-risk men, screening higher-risk men at an earlier age, and tailoring screening intervals based on Prostate Specific Antigen (PSA) level at a previous test. There was agreement that inclusion of magnetic resonance imaging (MRI) in the pathway should be considered, but disagreement on the inclusion of other new biomarkers.


In disease areas where many potential screening pathways exist and technologies are rapidly evolving, a modified-Delphi provides a useful tool to identify strategies that are important to compare when providing recommendations to decision-makers.

Impact statement

This research draws together expert opinion on prostate cancer screening, thereby focusing future research on the areas important to decision-makers.