{'fraction_non_alphanumeric': 0.030710172744721688, 'fraction_numerical': 0.016634676903390915, 'mean_word_length': 5.569327731092437, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
20 Systematic review registration in headache disorders

Objectives The principles of the Evidence Based Medicine (EBM) manifesto focus in part on: identifying and fixing problems with research evidence, improving the quality of evidence, increasing research transparency, and reducing research waste1. Systematic Reviews (SRs), one method of synthesizing existing evidence, can be used to inform clinical practice guidelines (CPGs) and policy decisions. With the advent of SR registries such as PROSPERO2, and the ability to prospectively register SR protocols, there has been an increased awareness regarding registration and transparency in the production of SRs. Registration can reduce research waste by informing prospective reviewers of planned and ongoing reviews, mitigating duplication of effort and resources for similar reviews. The primary objectives of this study are to: (1) identify the number of SRs prospectively registered in headache and migraine disorders within PROSPERO or in a scientific journal, and (2) understand reasons for not registering prior to publication through qualitative surveys among authors of SRs that did not have a prospective protocol. The secondary aims of this study – among those reviews which were registered – are to identify: (1) how many primary outcomes are discrepant or discordant with those reported in PROSPERO/published protocol and the completed systematic review, (2) how many outcomes were completely specified in the published protocol, and (3) how frequently was the PRISMA checklist used to report published systematic reviews. Method To locate published migraine and headache SR protocols, the following electronic databases will be searched: MEDLINE (via Pubmed), EMBASE (via SCOPUS), Joanna Briggs Institute, Cochrane Library, Campbell Collaboration, and Open Science Framework. The time range will cover all records between February 2011 - May 2019. Qualtrics will be used to develop and distribute surveys to SR authors when necessary. Citations will be managed using Endnote. To assess completeness in outcome reporting in SRs published in PROSPERO or protocol registration, we will use the Saldanha and colleagues (2014)3 five-element framework. Results The study design is still in the planning phase; there are no results to report at this moment. Conclusions Prospective registration of systematic reviews promotes honesty and transparency, and aids in reducing research waste and bias in the production and dissemination of systematic reviews. This ultimately results in better evidence to be used by policy makers, CPG developers, consumers, patients, academics, and clinicians. References Heneghan C, Mahtani KR, Goldacre B, et al. Evidence based medicine manifesto for better healthcare. BMJ2017;357:j2973. Booth A, Clarke M, Dooley G, et al. The nuts and bolts of PROSPERO: an international prospective register of systematic reviews. Syst Rev 2012;1:2 Saldanha IJ, Dickersin K, Wang X, et al. Outcomes in Cochrane systematic reviews addressing four common eye conditions: an evaluation of completeness and comparability. PloS one2014;9(10):e109400