Trial Registry Use in Surgery Systematic Reviews: A Cross-Sectional Study.

OBJECTIVE: To determine the extent to which systematic reviews published in surgery journals reported a clinical trial registry search as part of their search strategy and whether systematic reviews that omitted such searches would have located additional trials for inclusion. BACKGROUND: Systematic reviews are used by clinicians to guide clinical decision making. When conducting systematic reviews, the comprehensive search strategy is particularly critical to identify all studies-whether published or not-for producing an overall summary effect. Inclusion of only published studies may lead to overestimated and inaccurate summary effects; thus, it is important to consider unpublished studies. Here, we investigate the extent of clinical trial registry searches performed in surgical systematic reviews because trial registries may be the most viable approach to locate unpublished trial data. METHODS: We retrieved systematic reviews from the top surgery journals and the Cochrane Collaboration. Each was reviewed to determine which bibliographic databases were used and which, if any, trial registries were searched. RESULTS: Of 996 total systematic reviews, 252 (25.3%) reported having included a clinical trial registry search, with systematic reviews published in journals reporting searches of unpublished research at a rate of 6.4% (47/737). Reviews published by the Cochrane Collaboration included searches of unpublished research 79.2% of the time (205/259). CONCLUSIONS: Many systematic reviews published in surgery journals include only published research, which may contribute to publication bias. We recommend that authors maximize available information by using unpublished trial data found in clinical trial registries.

Insulin selectively reduces mitochondrial uncoupling in brown adipose tissue in mice.

The purpose of the present study was to determine the effects of prolonged hyperinsulinemia on mitochondrial respiration and uncoupling in distinct adipose tissue depots. Sixteen-week-old male mice were injected daily with placebo or insulin to induce an artificial hyperinsulinemia for 28 days. Following the treatment period, mitochondrial respiration and degree of uncoupling were determined in permeabilized perirenal, inguinal, and interscapular adipose tissue. White adipose tissue (WAT) mitochondria (inguinal and perirenal) respire at substantially lower rates compared with brown adipose tissue (BAT). Insulin treatment resulted in a significant reduction in mitochondrial respiration in inguinal WAT (iWAT) and interscapular BAT (iBAT), but not in perirenal WAT (pWAT). Furthermore, these changes were accompanied by an insulin-induced reduction in UCP-1 (uncoupling protein 1) and PGC-1α in iWAT and iBAT only, but not in pWAT or skeletal muscle. Compared with adipose tissue mitochondria in placebo conditions, adipose tissue from hyperinsulinemic mice manifested a site-specific reduction in mitochondrial respiration probably as a result of reduced uncoupling. These results may help explain weight gain so commonly seen with insulin treatment in type 2 diabetes mellitus.

Clinical Trial Registry Use in Orthopaedic Surgery Systematic Reviews.

BACKGROUND: Results from systematic reviews and meta-analyses, which have the highest level of evidence (Level I), often drive clinical decision-making and health policy. Often, unpublished trial data are omitted from systematic reviews, raising concerns about the extent of the reliability and validity of results that have been drawn from systematic reviews. We aimed to determine the extent to which systematic review authors include searches of clinical trial registries for unpublished data when conducting systematic reviews in orthopaedic surgery. METHODS: Systematic reviews and/or meta-analyses were gathered from the top 5 orthopaedic surgery journals based on the h5-index from Google Scholar Metrics. Systematic reviews that had been published in the Cochrane Database of Systematic Reviews, which requires the inclusion of a clinical trial registry search, served as controls. For the primary outcome, each systematic review from the top 5 orthopaedic journals was screened to determine whether the authors of each study searched for unpublished data in clinical trial registries. We then compared the rate of registry searches with those in the control group. For the secondary analysis, a search of ClinicalTrials.gov was performed for unpublished trial data for 100 randomized systematic reviews. RESULTS: All 38 of the Cochrane systematic reviews (100%) included clinical trial registry searches, while the top 5 orthopaedic journals had only 31 of 480 studies (6.5%) that looked at clinical trial registries. The secondary analysis yielded 59 of 100 systematic review articles (59.0%) that could have included unpublished clinical trial data from ≥1 studies to their sample. CONCLUSIONS: Systematic reviews that have been published in the top orthopaedic surgery journals seldom included a search for unpublished clinical trial data. CLINICAL RELEVANCE: The exclusion of clinical trial registry searches potentially contributes to publication bias within the orthopaedic literature. Moving forward, systematic review authors should include clinical trial registry searches for unpublished clinical trial data to provide the most accurate representation of the available evidence for systematic reviews and meta-analyses.

Evaluation of spin in the abstracts of otolaryngology randomized controlled trials.

OBJECTIVE: Spin, the misrepresentation and distortion of research findings, has been shown to affect clinical decision making. Spin has been found in randomized controlled trials (RCTs) published in various fields of medicine, but no study has tested for the presence of spin in otolaryngology RCTs. The purpose of this study is to evaluate the abstracts of RCTs found in the otolaryngology literature for spin. METHODS: In this cross-sectional analysis, we analyzed the abstracts of RCTs for spin using a pilot-tested form. Double data extraction was performed by two blinded authors, and discrepancies were resolved using mutual discussion. RESULTS: Out of the 534 PubMed citations retrieved by our search string, 162 parallel-group RCTs with clearly defined primary and secondary endpoints were identified. Further analysis identified 47 trials with nonsignificant primary outcomes, which were then evaluated for spin. Spin was identified in 33 of the 47 (70%) abstracts. Spin was found in the results sections of 25 (53%) of the included abstracts and was found in the conclusion section of 27 (57%) of the abstracts. Spin was not present in the titles of any of the included studies. CONCLUSION: Spin was common in our sample of otolaryngology RCTs. Spin may potentially create false impressions about the true validity of a drug or intervention. Further research needs to test for potential clinical implications of spin in the otolaryngology literature. LEVEL OF EVIDENCE: NA. Laryngoscope, 2018.