Demographic analysis of randomized controlled trials in bladder cancer

Objective To demographically examine randomized controlled trials (RCTs) that have been conducted in bladder cancer over a predefined time period. Methods Various techniques have been described to detect RCTs using different databases. We searched the MEDLINE database by crossing the heading 'Urinary bladder neoplasms' with the MeSHs 'Clinical trial$. mp. OR clinical trial. pt. OR random:. mp. OR tu. xs.' between 1995 and 2010. For the RCTs identified, analysis was performed on each RCT, placing particular emphasis on modality of intervention, cohort size, principal author, region, journal type, disease status, histology, blinding, number of centres involved, performance of a statistical power calculation, accrual status and trial support. Results Of 5002 RCT bladder cancer papers retrieved over the given period, only 238 represented actual RCTs after manual appraisal. More than half of the RCTs investigated medical and surgical therapies (54.2%), and only half had a sample size of > 100 patients. A small percentage of studies were double-blinded (8.0%), and there was an almost equal distribution of multicentre vs single centre trials (54.6% vs 45.4%). More studies were conducted in Europe (61.3%) than the rest of the world combined, with urologists principally the lead investigators in the majority (72.3%). Most studies were conducted on patients with urothelial carcinoma (97.1%), with less than one-third reporting a statistical power calculation (31.5%). Conclusions Only 238 RCTs were published for bladder cancer between 1995 and 2010. RCTs are under-utilized in bladder cancer. More trials need to be designed with larger sample sizes in order to optimize diagnostic and treatment strategies for patients with bladder cancer.