Shared decision making for men facing prostate cancer treatment: a systematic review of randomized controlled trials

Aims: To synthesize the empirical evidence on the effectiveness of shared decision making (SDM) compared to usual care for prostate cancer (PC) treatment. Methods and results: A systematic review of academic (MEDLINE, EMBASE, Cochrane Library, CINHAL, PsychINFO, and Scopus) and grey (clinicaltrials.gov, WHO trial search, meta-Register ISRCTN, Google Scholar, opengrey, and ohri.ca) literature, also identified from contacting authors and hand-searching bibliographies. We included randomized controlled trials (RCTs): 1) comparing SDM to usual care for decisions about PC treatment, 2) conducted in primary or specialized care, 3) fulfilling the key SDM features, and 4) reporting quantitative outcome data. Four RCTs from Canada (n=3) and the USA were included and comprised 1,065 randomized men, most (89.8%) of whom were in PC stage T1-T2. The studies reported 24 outcome measures. In 62.5% study estimates, SDM was similar to usual care at improving patient satisfaction and mood, and at reducing decisional conflict and decisional regret. In 37.5% study estimates, SDM significantly improved knowledge, perception of being informed and patient-perceived quality of life (QoL) at four weeks. There was a dearth of outcome data, particularly on the adherence to treatment and on patient-important and clinically relevant health outcomes such as symptoms and mortality. Conclusion: SDM may positively influence men's knowledge and may have a positive but short-term effect on patient-perceived QoL. The (long-term) effects of SDM on patient-related outcomes for decisions about PC treatment are unclear. Future research needs consensus about the interventions and outcomes needed to evaluate SDM and should address the absence of evidence on health outcomes.