Abstract
Objectives: To identify whether Mendelian randomisation (MR) studies are appropriately conducted and reported in enough detail for other researchers to accurately replicate and interpret them.
Design: Cross-sectional meta-epidemiological study.
Data sources: Web of Science, EMBASE, PubMed and PsycINFO were searched on 15 July 2022 for literature.
Eligibility criteria: Full research articles that conducted an MR analysis exclusively using individual-level UK Biobank data to obtain a causal estimate of the exposure-outcome relationship (for no more than ten exposures or outcomes).
Methods and analysis: Data were extracted using a 25-item checklist relating to reporting and methodological quality (based on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)-MR reporting guidelines and the guidelines for performing MR investigations). Article characteristics, such as 2021 Journal Impact Factor, publication year, journal word limit/recommendation, whether the MR analysis was the primary analysis, open access status and whether reporting guidelines were followed, were also extracted. Descriptive statistics were calculated for each item, and whether article characteristics predicted overall article completeness was investigated with linear regression.
Results: 116 articles were included in this review. The proportion of articles which reported complete information/adequate methodology ranged from 3% to 100% across the different items. Palindromic variants, variant replication, missing data, associations of the instrumental variable with the exposure or outcome and bias introduced by two-sample methods used on a single sample were often not completely addressed (<11%). There was no clear evidence that article characteristics predicted overall completeness except for primary analysis status.
Conclusions: The results identify areas in which the reporting and conducting of MR studies needs to be improved and also suggest researchers do not make use of supplementary materials to sufficiently report secondary analyses. Future research should focus on the quality of code and analyses, attempt direct replications and investigate the impact of the STROBE-MR specifically.
Study registration https://osf.io/nwrdj
| Original language | English |
|---|---|
| Pages (from-to) | 103-110 |
| Number of pages | 8 |
| Journal | BMJ Evidence-Based Medicine |
| Volume | 28 |
| Issue number | 2 |
| Early online date | 8 Dec 2022 |
| DOIs | |
| Publication status | Published - 1 Apr 2023 |
Data Availability Statement
Data are available in a public, open access repository. The data are available via the University of Bristol online data repository athttps://doi.org/10.5523/bris.2voc5xy13adqs2rimeateez14yand at https://codeocean.com/capsule/1654662/tree/v1.Funding
MJG, AC and MRM are supported by the Medical Research Council Integrative Epidemiology Unit (MC_UU_00011/7). FS, JNK and RCR are supported by a Cancer Research UK programme grant (the Integrative Cancer Epidemiology Programme C18281/A29019). RCR is a de Pass Vice Chancellor’s Research Fellow at the University of Bristol. The funders had no role in the study design, collection or analysis of data, or interpretation of results.
Keywords
- Epidemiology
- Public health
ASJC Scopus subject areas
- General Medicine
