Clinical Trials in Urology: Predictors of Successes and Failures.

PURPOSE: Clinical trials serve as a critical source of information to guide evidence-based practices in urology. Conversely, trials that are abandoned consume significant resources and results are under-reported in the literature. MATERIALS AND METHODS: ClinicalTrials.gov was queried for urology trials from 2006-2016. Trials were screened by two screeners for applicability to urology and disputes were resolved by a third independent reviewer. 1,340 trials met final inclusion criteria (722 successful trials, 618 failed trials). Univariable analysis utilized Fisher's Exact, Chi-Squared, and Wilcoxon Rank-Sum tests. Trial characteristics, including AUA section, phase, subspecialty, intervention type, source of funding, and randomization were examined for association with failure using multivariable logistic regression. RESULTS: Trial failure is associated with Oncology subspecialty (Adjusted Odds Ratio [AOR] 2.25, 95% CI 1.60-3.18), Infertility/Andrology subspecialty (AOR 4.99, CI 1.60-17.61), device trials (AOR 1.64, CI 1.00-2.70), and combination funding by industry/government/grants (AOR 3.13, CI 2.21-4.48). Clinical trials in AUA sections were less likely to fail than international and multi-sectional trials. Among trials that failed, poor accrual was the primary reason for trial failure, comprising 41% of all failures. Other reasons for failure include inadequate budget (9%), sponsor cancellation (7%), poor interim results (7%), and toxicity (3%). CONCLUSIONS: Despite their significance, many urological trials fail prematurely due to poor accrual. Complex features inherent to Oncology, Andrology/Infertility, devices, and multi-sectional trials pose significant barriers to success.