Study structure may compromise understanding of longitudinal decision regret stability: A systematic review

To perform a systematic review of decision regret studies in cancer patients to determine if regret is longitudinally stable, and whether these study structures account for late-emerging treatment effects.

Online databases including the George Mason Libraries, Global Health, Nursing and Allied Health, and PubMed were searched to identify decision regret studies with longitudinal components in patients with cancer.

A total of 845 unique citations were identified; 20 studies met inclusion criteria. Data was also collected on the time horizon for 90 studies; 47 % of studies evaluated regret at time points of one year or less, although this has increased significantly in prostate cancer citations since 2010. Regret was infrequent, affecting less than 20 % of patients, and often stable. Effect sizes in studies where decision regret changed over time were small to negligible.

Longitudinal effects can influence the expression of decision regret, yet many studies are not designed to collect long-term data; prostate cancer studies may be particularly disadvantaged. The degree of this influence in current studies is small, though this outcome must be interpreted with caution.

Providers should be aware of the risk of late-emerging regret and counsel patients appropriately.