Tools for assessing quality and risk of bias in Mendelian randomization studies: a systematic review
Year: 2022
Type: review
Study design: Systematic Review
Abstract: BACKGROUND: The use of Mendelian randomization (MR) in epidemiology has increased considerably in recent years, with a subsequent increase in systematic reviews of MR studies. We conducted a systematic review of tools designed for assessing risk of bias and/or quality of evidence in MR studies and a review of systematic reviews of MR studies. METHODS: We systematically searched MEDLINE, Embase, the Web of Science, preprints servers and Google Scholar for articles containing tools for assessing, conducting and/or reporting MR studies. We also searched for systematic reviews and protocols of systematic reviews of MR studies. From eligible articles we collected data on tool characteristics and content, as well as details of narrative description of bias assessment. RESULTS: Our searches retrieved 2464 records to screen, from which 14 tools, 35 systematic reviews and 38 protocols were included in our review. Seven tools were designed for assessing risk of bias/quality of evidence in MR studies and evaluation of their content revealed that all seven tools addressed the three core assumptions of instrumental variable analysis, violation of which can potentially introduce bias in MR analysis estimates. CONCLUSION: We present an overview of tools and methods to assess risk of bias/quality of evidence in MR analysis. Issues commonly addressed relate to the three standard assumptions of instrumental variables analyses, the choice of genetic instrument(s) and features of the population(s) from which the data are collected (particularly in two-sample MR), in addition to more traditional non-MR-specific epidemiological biases. The identified tools should be tested and validated for general use before recommendations can be made on their widespread use. Our findings should raise awareness about the importance of bias related to MR analysis and provide information that is useful for assessment of MR studies in the context of systematic reviews.
DOI: 10.1093/ije/dyac149
Institutions: University of Bristol, MRC Integrative Epidemiology Unit
Language: English
Subfield: Statistics, Probability and Uncertainty
Field: Decision Sciences
Domain: Social Sciences
Open Access status: hybrid
Estimated APC paid: $3,879
Funders: National Institute on Handicapped Research, University Hospitals Bristol NHS Foundation Trust, NIHR Bristol Biomedical Research Centre, Cancer Research UK, National Institute for Health and Care Research, University of Bristol, Medical Research Council, National Institute for Health Research Applied Research Collaboration West
Awards: G1131969086, G1665228147, NIHR Senior Investigator Award, G2538597952, G2809956348, G3176767667, G323433674, G324601231, G3609641447, G3929269289, G475347556, G4834040652, G5371351582, G5992551002, NIHR Senior Investigator Award, Mendelian randomization to hypothesis-free causal inference, G7990456425, G8201869620, G8502142660, G8670130177
OpenAlex ID: W4288432193