CONSORT–Consolidated Standards of Reporting Trials: Evidence-based, minimum recommendations for reporting RCTs; 25-item checklist.
PRISMA–Preferred Reporting Items for Systematic Reviews and Meta-Analyses: Evidence-based minimum set of items for reporting in systematic reviews and meta-analyses.
See also, NLM's Research Reporting Guidelines and Initiatives – A comprehensive chart of major biomedical research reporting guidelines.
Cochrane Handbook for Systematic Reviews of Interventions -- Cochrane's official document that describes the process of preparing and maintaining Cochrane systematic reviews on the effects of healthcare interventions.
Institute of Medicine's Standards for Systematic Reviews -- Addresses the entire systematic review process, from locating, screening, and selecting studies for the review, to synthesizing the findings (including meta-analysis) and assessing the overall quality of the body of evidence, to producing the final review report.