Despite efforts to spur pediatric research, there is a paucity of pediatric-specific research data available to guide clinical decisionmaking. Searching the grey literature improves the identification of evidence not found in the peer-reviewed literature and may prove particularly valuable for pediatric research synthesis. The objective of this methodology report is to examine the feasibility and additional utility--in terms of impact on risk of bias and strength of evidence assessments--of comprehensive searches of trials registries to supplement the evidence identified in an ongoing systematic review on tympanostomy tubes in children with otitis media conducted by the Brown Evidence-based Practice Center (EPC).
We conducted searches in ClinicalTrials.gov and the International Clinical Trials Registry Platform, using terms that matched those used in the original review database searches.
Six studies were identified in both the registries and the original review. Overall the agreement for design, arm information, baselines, and results was very close, but prespecified outcomes in almost all of the records differed from the outcomes in the publications based on those records. Twenty studies were screened in via registry searches but not found in the original review. Two gave results, but we were unable to incorporate them in to the analysis, due to the fact that they had no statistical analyses. The results of these trials would not have changed our initial meta-analyses, risk of bias, or strength or evidence assessments. Seven of the records without results indicate studies with completion dates in the future or recent past. The information about these studies can be used to inform future research needs. We were able to find a registry record for only four of the 178 studies in the original review.
This project yields limited evidence on the utility of searching ClinicalTrials.gov, because only six records were found that matched papers in the report, along with two others that yielded new results. Based on the evidence we found, there does not appear to be an impact on the conclusions or strength of evidence in the report of including records from ClinicalTrials.gov and ICTRP. One way in which conducting a registry search is of value to a systematic review project is in identifying ongoing research, as well as gaps in knowledge, and facilitating prioritization of future research to reduce redundancy.
Adam GP, Springs S, Langberg V, Halliday C, Trikalinos TA. Supplemental Project to Assess the Transparency of Reporting Requirements: Tympanostomy Tubes in Children With Otitis Media. Methods Research Report. (Prepared by the Brown University Evidence-based Practice Center under Contract No. 290-2015-00002-I; 290-32004-T). AHRQ Publication No. 17-EHC018-EF. Rockville, MD: Agency for Healthcare Research and Quality. June 2017. www.effectivehealthcare.ahrq.gov/reports/final.cfm. DOI: https://doi.org/10.23970/ AHRQEPCMETH2.