Dorsey-Treviño, Edgar Gerardo

Objectives To improve the trustworthiness of evidence, studies should be prospectively registered and research reports should adhere to existing standards. We aimed to systematically assess the degree to which endocrinology and internal medicine journals endorse study registration and reporting standards for randomised controlled trials (RCTs), systematic reviews (SRs) and observational studies (ObS). Additionally, we evaluated characteristics that predict endorsement of reporting or registration mechanism by these journals. Design Meta-epidemiological study. Setting Journals included in the ‘Endocrinology and Metabolism’ and ‘General and Internal Medicine’ 2017 Journal Citation Reports. Participants Journals with an impact factor of ≥1.0, focused on clinical medicine, and those who publish RCTs, SRs and ObS were included. Primary outcomes Requirement of adherence to reporting guideline and study registration as determined from the journals’ author instructions. Results Of the 170 (82 endocrinology and 88 internal medicine) eligible journals, endorsing of reporting standards was the highest for RCTs, with 35 (43%) of endocrine journals and 55 (63%) of internal medicine journals followed by SRs, with 21 (26%) and 48 (55%), respectively, and lastly, by ObS with 41 (50%) of endocrine journals and 21 (24%) of internal medicine journals. In 78 (46%) journals RCTs were required to be registered and published in adherence to the Consolidated Standards of Reporting Trials statement. Only 11 (6%) journals required registration of SRs. Internal medicine journals were more likely to endorse reporting guidelines than endocrine journals except for Strengthening the Reporting of Observational Studies in Epidemiology. No other journal characteristic proved to be an independent predictor of reporting standard endorsement for RCTs besides trial registration. Conclusion Our results highlight that study registration requirement and reporting guideline endorsement are suboptimal in internal medicine and endocrine journals. This malpractice may be further enhanced since endorsement does not imply enforcement, impairing the practice of evidence-based medicine.

Introduction Sodium glucose cotransporter 2 (SGLT-2) inhibitors are a relatively new drug-class of glucose-lowering medications. Several trials and systematic reviews have demonstrated their beneficial effect on some macrovascular outcomes. Their effect on microvascular outcomes has been reported as positive in several trials, however, their effect remains uncertain. Therefore, we report the protocol of a systematic review and meta-analysis aimed at determining the effect of SGLT-2 inhibitors regarding patient-important and surrogate microvascular outcomes in patients with type 2 diabetes. Methods and analysis A comprehensive search will be conducted to find eligible articles from each database’s earliest inception to November 2017. These databases will include Ovid, MEDLINE, EMBASE, Web of Science, and Scopus. We will search for randomized controlled trials (RCTs) that compare any of the SGLT-2 inhibitors with any other active treatment or placebo assessing microvascular outcomes in either their primary or secondary outcomes. Reviewers working independently and in duplicate will review all abstracts, and full-text manuscripts for eligibility, and will systematically extract the data and will assess the risk of bias in the included studies. Random-effects models will also be used. Ethics and dissemination The results of the systematic review will be disseminated via publication in a peer-reviewed journal regardless of outcome and will be presented at relevant conferences. The data we will use do not include individual patient data, so ethical approval is not required PROSPERO registration number CRD42017076460.