Level of evidence, sponsorship, conflict of interest policy and commercial impact of PubMed-listed clinical urolithiasis-related trials in 2014

Objectives To evaluate published trials on urolithiasis regarding level of evidence, type of sponsorship and declared conflicts of interest (COIs), and to elucidate a potential commercial impact. Materials and Methods We performed a systematic PubMed^® literature search using a predefined Boolean search term to identify PubMed-listed clinical research studies on urolithiasis in 2014 (fourth quarter). All authors screened the results for eligibility criteria and two independent reviewers evaluated and performed data extraction of predefined endpoints, including level of evidence, declaration of COI and sponsorship/funding (as indicated in the published print version), and commercial impact. Results A total of 110 clinical trials in urolithiasis listed in PubMed met the inclusion criteria. Levels of evidence 1, 2, 3 and 4 were found in 15%, 14%, 21% and 51% of trials, respectively. A COI was indicated in a total of 90% of publications, 93% of which declared no existing conflict of interest. Sponsorship was indicated in 36% of publications, 55% of which stated public funding, 33% institutional funding, 10% industrial funding and 2% both public and industrial funding. A total of 11% of the published trials were rated as having a high commercial impact. Conclusion The present study provides evidence of increasing levels of evidence for published clinical trials on urolithiasis in 2014 (as compared with earlier data). Ninety percent of publications indicated conflicts of interest, whereas sponsoring of studies was declared only by one-third. A considerable number of trials involved issues of high commercial impact. Recently established legal programmes and voluntary acts on self-reporting of financial relationships will enhance transparency in the future; however, increased public funding will be needed to further promote the quality of trials on urolithiasis.