Abstract Purpose: The purpose of this study was to evaluate the quality of reporting in the abstracts of oncology systematic reviews using PRISMA guidelines for abstract writing. Methods: Oncology systematic reviews and meta-analyses from four journals - The Lancet Oncology, Clinical Cancer Research, Cancer Research, and Journal of Clinical Oncology - were selected using a PubMed search. The resulting 337 abstracts were sorted for eligibility and 182 were coded based on a standardized abstraction manual constructed from the PRISMA criteria. Eligible systematic reviews were coded independently and later verified by a second coder, with disagreements handled by consensus. One hundred eighty-two abstracts comprised the final sample. Results: The number of included studies, information regarding main outcomes, and general interpretation of results were described in the majority of abstracts. In contrast, risk of bias or methodological quality appraisals, the strengths and limitations of evidence, funding sources, and registration information were rarely reported. By journal, the most notable difference was a higher percentage of funding sources reported in Lancet Oncology. No detectable upward trend was observed on mean abstract scores after publication of the PRISMA extension for abstracts. Conclusion: Overall, the reporting of essential information in oncology systematic review and meta-analysis abstracts is suboptimal and could be greatly improved. Keywords: Review, Systematic; Meta-Analysis; Cancer; Medical Oncology; Abstracting as Topic; Funding

ABSTRACT Objectives: We evaluated the use of clinical trials registries in published obstetrics and gynecological systematic reviews and meta-analyses. Methods: A review of publications between January 1, 2007, and December 31, 2015, from six obstetrical and gynecological journals (_Obstetrics & Gynecology, Obstetrical & Gynecological Survey, Human Reproduction Update, Gynecologic Oncology, British Journal of Obstetrics and Gynaecology, and American Journal of Obstetrics & Gynecology_) was completed to identify eligible systematic reviews. All systematic reviews included after exclusions were independently reviewed to determine if clinical trials registries had been included as part of the search process. Studies that reported using a trials registry were further examined to determine whether trial data was included in the analysis. Results: Our initial search resulted in 292 articles, which was narrowed to 256 after exclusions. Of the 256 systematic reviews meeting our selection criteria, 47 utilized a clinical trials registry. Eleven of the 47 systematic reviews found unpublished data, and added the unpublished trial data into their results. Conclusion: A majority of systematic reviews in clinical obstetrics and gynecology journals do not conduct searches of clinical trials registries or do not make use of data obtained from these searches.