Quality Assessment and Relevant Clinical Impact of Randomized Controlled Trials of Varicocele: Next Step to Good-Quality Randomized Controlled Trial of Varicocele Treatment

Purpose: To assess the quality of randomized controlled trials (RCTs) on varicocele published from 1979 to 2017. Materials and Methods: We searched for original RCT on varicocele published between 1979 and 2017. Jadad scale, van Tulder scale, and Cochrane Collaboration Risk of Bias Tool were used to analyze RCT quality over time. Effects on RCT quality including funding source, Institutional Review Board (IRB) approval, and intervention were assessed. Treatment parameters of varicocele were also analyzed. Results: Blinding and allocation concealment were described in 25.9% and 9.4% of RCT, respectively. Both tended to increase and a sharp dip in allocation concealment was observed in 2010-2017. Jadad scores increased steadily from 1979 to 2017 (1.28 +/- 0.59 to 2.19 +/- 1.10, p<0.01). Van Tulder scores tended to increase from 1979 to 2017 (4.21 +/- 0.94 to 5.58 +/- 1.58, p<0.01). RCTs with funding statements had higher Jadad (Yes vs. No, 3.25 +/- 0.50 vs. 1.70 +/- 0.97; p<0.01) and van Tulder (Yes vs. No, 7.25 +/- 1.26 vs. 4.81 +/- 1.26; p<0.01) scores than unfunded RCTs. IRB approval and intervention were associated with better quality. Conclusions: The number of RCTs on varicocele increased from 1979 to 2017. Also, quality improved over time with increasing IRB approval, funding, and multicenter trial. Most RCTs on varicocele reported the use of surgical treatment. RCTs of surgical treatments have limitations to satisfy the condition of RCT to conduct, but their quality has improved over time.