{"doi":"10.1136/bmj.d7762","title":"Assessment of publication bias, selection bias, and unavailable data in meta-analyses using individual participant data: a database survey","abstract":null,"journal":"BMJ","year":2012,"id":636372,"datarank":0.9027889821744353,"base_score":6.018593214496234,"endowment":6.018593214496234,"self_citation_contribution":0.9027889821744353,"citation_network_contribution":0.0,"self_endowment_contribution":0.9027889821744353,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":410,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":2286,"name":"A. J. Sutton","orcid":null,"position":1,"is_corresponding":false},{"id":1651588,"name":"R. D. Riley","orcid":null,"position":2,"is_corresponding":false},{"id":92561,"name":"I. Ahmed","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Assessment of publication bias, selection bias, and unavailable data in meta-analyses using individual participant data: a database survey","abstract":"OBJECTIVE: To examine the potential for publication bias, data availability bias, and reviewer selection bias in recently published meta-analyses that use individual participant data and to investigate whether authors of such meta-analyses seemed aware of these issues. DESIGN: In a database of 383 meta-analyses of individual participant data that were published between 1991 and March 2009, we surveyed the 31 most recent meta-analyses of randomised trials that examined whether an intervention was effective. Identification of relevant articles and data extraction was undertaken by one author and checked by another. RESULTS: Only nine (29%) of the 31 meta-analyses included individual participant data from \"grey literature\" (such as unpublished studies) in their primary meta-analysis, and the potential for publication bias was discussed or investigated in just 10 (32%). Sixteen (52%) of the 31 meta-analyses did not obtain all the individual participant data requested, yet five of these (31%) did not mention this as a potential limitation, and only six (38%) examined how trials without individual participant data might affect the conclusions. In nine (29%) of the meta-analyses reviewer selection bias was a potential issue, as the identification of relevant trials was either not stated or based on a more selective, non-systematic approach. Investigation of four meta-analyses containing data from ≥10 trials revealed one with an asymmetric funnel plot consistent with publication bias, and the inclusion of studies without individual participant data revealed additional heterogeneity between trials. CONCLUSIONS: Publication, availability, and selection biases are a potential concern for meta-analyses of individual participant data, but many reviewers neglect to examine or discuss them. These issues warn against uncritically viewing any meta-analysis that uses individual participant data as the most reliable. Reviewers should seek individual participant data from all studies identified by a systematic review; include, where possible, aggregate data from any studies lacking individual participant data to consider their potential impact; and investigate funnel plot asymmetry in line with recent guidelines.","is_dataset_classified":null,"base_score":6.018593214496234,"endowment":6.018593214496234,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"22214758","pmcid":null,"openalex_id":"https://openalex.org/W2137670391","authors":[],"funders":[{"funder_name":"Medical Research Council","grant_id":"G0800808","title":null}],"total_grants":1,"fwci":21.6613,"citation_percentile":0.99509067,"influential_citations":0,"citation_trend":[{"year":2012,"count":14},{"year":2013,"count":22},{"year":2014,"count":22},{"year":2015,"count":15},{"year":2016,"count":29},{"year":2017,"count":27},{"year":2018,"count":24},{"year":2019,"count":54},{"year":2020,"count":38},{"year":2021,"count":41},{"year":2022,"count":35},{"year":2023,"count":30},{"year":2024,"count":30},{"year":2025,"count":25},{"year":2026,"count":4}],"oa_status":"hybrid","license":"cc-by-nc","oa_locations":[{"url":"https://www.bmj.com/content/bmj/344/bmj.d7762.full.pdf","host_type":"journal"},{"url":"https://www.bmj.com/content/bmj/344/bmj.d7762.full.pdf","host_type":"publisher"},{"url":"https://syndication.highwire.org/content/doi/10.1136/bmj.d7762","host_type":"publisher"},{"url":"https://doi.org/10.1136/bmj.d7762","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/22214758","host_type":"repository"},{"url":"http://hdl.handle.net/2381/11847","host_type":"repository"},{"url":"https://research.birmingham.ac.uk/en/publications/0509ddca-d324-40af-b5cd-41913c3b5ee7","host_type":"repository"},{"url":"https://research.birmingham.ac.uk/portal/en/publications/assessment-of-publication-bias-selection-bias-and-unavailable-data-in-metaanalyses-using-individual-participant-data-a-database-survey(0509ddca-d324-40af-b5cd-41913c3b5ee7).html","host_type":"repository"}],"fields_of_study":["Meta-analysis and systematic reviews","Animal testing and alternatives","scientometrics and bibliometrics research","Databases, Bibliographic","Meta-Analysis as Topic","Peer Review, Research","Publication Bias","Randomized Controlled Trials as Topic","Selection Bias"],"mesh_terms":["Meta-Analysis as Topic","Selection Bias","Randomized Controlled Trials as Topic","Databases, Bibliographic","Publication Bias","Peer Review, Research"],"keywords":["Publication bias","Funnel plot","Meta-analysis","Data extraction","Selection bias","Reporting bias","Identification (biology)","Systematic review","Data collection","Research design","MEDLINE","Psychology","Medicine","Statistics","Mathematics","Biology"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Reduced inequalities"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-06T16:55:00.595946Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}