Clinical trial registry use in minimally invasive surgical oncology systematic reviews and meta-analyses

Abstract

Publication bias can arise in systematic reviews when unpublished data are omitted and lead to inaccurate clinical decision making and adverse clinical outcomes. By conducting searches of clinical trial registries (CTRs), researchers can create more accurate systematic reviews and mitigate the risk of publication bias. The aims of this study are: to evaluate CTR use in systematic reviews and meta-analyses within the minimally invasive surgical oncology (MISO) literature; to conduct a search of ClinicalTrials.gov for a subset of reviews to determine if eligible trials exist that could have been used. This is a cross-sectional study of 197 systematic reviews and meta-analyses retrieved from PubMed. Of 137 included studies, 18 (13.1%) reported searching a CTR. Our ClinicalTrials.gov search revealed that of the 25 randomly selected systematic reviews that failed to conduct a trial registry search, 16 (64.0%) would have identified additional data sources. MISO systematic reviews and meta-analyses do not regularly use CTRs in their data collection, despite eligible trials being freely available.

Impact of searching clinical trials registers in systematic reviews of pharmaceutical and non‐pharmaceutical interventions: Reanalysis of meta‐analyses

“…Our findings also agree with two studies which examined the number of trials identified via http://clinialtrials.gov for systematic reviews of surgical interventions 12,14 . Fuller et al found additional eligible trials for 64% (16/25) of the reviews, 12 while Reddy et al found additional eligible studies for 59% (59/100) of reviews 14 .…”

“…[7][8][9][10][11][13][14][15][16]24 Our findings also agree with two studies which examined the number of trials identified via ClinialTrials.gov for systematic reviews of surgical interventions. 12,14 Fuller et al found additional eligible trials for 64% (16/ 25) of the reviews, 12 while Reddy et al found additional eligible studies for 59% (59/100) of reviews. 14 Similarly, we identified additional trials for 60% (15/25) of the reviews of surgical interventions included in our study from different surgical subspecialities; mostly from orthopaedics surgery, followed by general surgery, neurosurgery, and bariatric surgery.…”

“…6 Previous studies have indicated underutilization of searching trials registers in most medical systematic reviews. [7][8][9][10][11][12][13][14][15][16] In a cross-sectional study of 117 systematic reviews that were published between 1 July 2012, and 30 June 2013, in six high impact medical journals, only 41 (35%) reviews reported searching a trials register. 15 This study and others have found the percentage of reviews searching trials registers varied from one medical specialty to another.…”

“…Previous studies have indicated underutilization of searching trials registers in most medical systematic reviews 7–16 . In a cross‐sectional study of 117 systematic reviews that were published between 1 July 2012, and 30 June 2013, in six high impact medical journals, only 41 (35%) reviews reported searching a trials register 15 .…”

“…Only a few studies have evaluated how often additional trials are identified via searching trials registers, and the impact of including the new trials on meta‐analysis results. Fuller et al examined a random sample of 25 minimally invasive surgical oncology reviews and found new trials for 64% (16/25) of the reviews 12 . Similarly, Reddy et al retrieved additional trials from trials registers for 59% (59/100) of orthopaedic surgery reviews 14 .…”