Methodology quality and grading recommendations in cancer screening guidelines: a systematic review

Introduction: Cancer prevention and screening guidelines are ideally suited to the task of providing high-quality and effective screening in clinical practice. We systematically reviewed cancer screening guidelines for recommended cancer prevention and screening interventions, in order to provide recommendations for development and implementation of high-quality guidelines. Methods: We included cancer screening and prevention recommendations mainly on lung, breast, gastric, liver, colorectal, and prostate from Pubmed, Embase, Web of Science, China Knowledge Resource Integrated Database, Wanfang Data, SinoMed, and then searched in other organizations’ website and database such as the United States Preventive Services Task Force, the American Cancer Society, the American College of Physicians, the National Comprehensive Cancer Network, the National Institute for Health and Care Excellence, European Society for Medical Oncology, and the National Guidelines Clearinghouse until June 30, 2018. An abstraction form to code information according to AGREE II was made and four researchers completed separately. The primary outcome was each recommendation’s quality; the second outcome was benefit-harm “comparability” rating, based on how benefits and harms were presented. Results: There are no high-quality guides in the 19 guides because each domain 3 didn’t reach 60 points, and only 2 guides scored above 50 points. 10 recommendations 9 guidelines were included, year from 2010 to 2018. The majority of guidelines (67%) were supported by a systematic review and that most guidelines had explicit criteria for rating the quality and strength of evidence (64% and 73%, respectively). 7 guidelines clearly mentioned benefits and harms, and 2 only mentioned relevant content. Four of the 55 recommendation statements we reviewed presented the benefits of the intervention in terms of a relative risk reduction (larger number) while presenting the harms in terms of an absolute risk reduction (smaller number). Conclusions：Our findings led us to consider potential contributors to the lack of clarity in guidelines. We recommend the use of “summary of findings” tables, an approach proposed in a series of papers from the GRADE guidelines group, as the best method of summarizing and presenting outcome information.