- Mendelian randomisation studies are increasingly used to analyse the causal effects of exposures and outcomes in diseases, but are often inadequately reported.
- The STROBE-MR reporting checklist has been developed to improve the reporting of Mendelian randomisation studies.
Mendelian randomisation (MR) is a popular method in epidemiology that uses genetic variation as a proxy for environmental exposures to understand the cause of diseases. Despite the increasing use and relevance of the technique, there is a lack of consensus on how to report MR studies. To address this need, a new STROBE guideline, Strengthening the Reporting of Observational Studies in Epidemiology using Mendelian Randomisation (STROBE-MR), has been published in the Journal of the American Medical Association (JAMA), with the explanation and elaboration paper published in The BMJ.
Associations between exposures and health outcomes reported in observational epidemiology studies are not always reliable due to confounding, or other forms of bias. Advances in technology have enabled identification of associations between genetic variations and exposures, traits, and health outcomes. MR uses these genetic variations as instrumental variables to analyse the effects of exposures on diseases. MR studies can therefore help understand the influence of exposure on various health, social and economic outcomes. As genetic variation is randomly inherited and cannot be affected by certain confounding factors, bias associated with other epidemiological study designs can be avoided using MR.
Mendelian randomisation studies provide an opportunity to study the causal association between an exposure and an outcome while reducing the risk of certain biases associated with traditional observational study designs.
Items in the existing STROBE checklist were either too general or did not apply to MR studies, while items specific to MR studies were missing. To help improve reporting on MR studies, a separate checklist was developed based on the STROBE guidelines, with 20 items covering specific recommendations for publications reporting MR studies. The checklist is also available on the EQUATOR Network website.
It is hoped that adoption of the STROBE-MR checklist by authors, reviewers and journal editors will improve the quality of MR study reports and enable consistent and transparent communication in this field.