{"doi":"10.1002/sim.4780080608","title":"The control of confounding by intermediate variables","abstract":"<jats:title>Abstract</jats:title><jats:p>In epidemiologic studies of the effect of an exposure on disease, the crude association of exposure with disease may fail to reflect a causal association due to confounding by one or more covariates. Most previous discussions of confounding in the epidemiologic literature have considered only point exposure studies, that is, studies that measure exposure and covariate status only once, at start of follow‐up. In this paper we offer definitions of confounding suitable for longitudinal studies that obtain data on exposure, covariate, and vital status at several points in time. An important difference between longitudinal studies and point exposure studies is that, in longitudinal studies, a time‐dependent covariate can be simultaneously a confounder and an intermediate variable on the causal pathway from exposure to disease. In this paper I propose an estimator, the extended standardized risk difference, that provides control for confounding by a covariate that is simultaneously a confounder and an intermediate variable.</jats:p>","journal":"Statistics in Medicine","year":1989,"id":18636,"datarank":17.62867433879986,"base_score":5.497168225293202,"endowment":5.497168225293202,"self_citation_contribution":0.8245752337939805,"citation_network_contribution":16.804099105005882,"self_endowment_contribution":0.8245752337939805,"citer_contribution":16.804099105005882,"corpus_percentile":null,"corpus_rank":null,"citation_count":243,"citer_count":200,"citers_with_citation_signal":200,"citers_with_endowment":200,"datacite_reuse_total":4,"is_dataset":false,"is_dataset_confidence":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":128814,"name":"James Robins","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":5.497168225293202,"endowment":5.497168225293202,"datacite_reuse_total":4,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"2749074","pmcid":null,"openalex_id":"https://openalex.org/W2169619449","authors":[],"funders":[{"funder_name":"NIEHS NIH HHS","grant_id":"5 SO4-ES00180","title":null},{"funder_name":"NIEHS NIH HHS","grant_id":"5 P30 ES00002","title":null}],"total_grants":2,"fwci":4.6901,"citation_percentile":0.9561625,"influential_citations":14,"citation_trend":[{"year":2012,"count":8},{"year":2013,"count":13},{"year":2014,"count":14},{"year":2015,"count":5},{"year":2016,"count":5},{"year":2017,"count":10},{"year":2018,"count":5},{"year":2019,"count":5},{"year":2020,"count":10},{"year":2021,"count":2},{"year":2022,"count":4},{"year":2023,"count":11},{"year":2024,"count":3},{"year":2025,"count":4}],"oa_status":"closed","license":"http://onlinelibrary.wiley.com/termsAndConditions#vor","oa_locations":[{"url":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fsim.4780080608","host_type":"publisher"},{"url":"https://onlinelibrary.wiley.com/doi/pdf/10.1002/sim.4780080608","host_type":"publisher"},{"url":"https://doi.org/10.1002/sim.4780080608","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/2749074","host_type":"repository"}],"fields_of_study":["Advanced Causal Inference Techniques","Health Systems, Economic Evaluations, Quality of Life","Statistical Methods and Bayesian Inference","Mathematics","Medicine","Data Interpretation, Statistical","Epidemiologic Methods","Epidemiology","Humans","Longitudinal Studies","Models, Statistical","Random Allocation","Risk Factors"],"mesh_terms":["Data Interpretation, Statistical","Epidemiologic Methods","Epidemiology","Humans","Longitudinal Studies","Mathematics","Random Allocation","Risk Factors","Models, Statistical"],"keywords":["Covariate","Confounding","Estimator","Statistics","Medicine","Econometrics","Mathematics"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[{"doi":"10.6084/m9.figshare.12750090.v1","title":"Additional file 1 of Doubly robust estimator of risk in the presence of censoring dependent on time-varying covariates: application to a primary prevention trial for coronary events with pravastatin","publisher":"figshare","resource_type":"JournalArticle"},{"doi":"10.6084/m9.figshare.12750090","title":"Additional file 1 of Doubly robust estimator of risk in the presence of censoring dependent on time-varying covariates: application to a primary prevention trial for coronary events with pravastatin","publisher":"figshare","resource_type":"JournalArticle"},{"doi":"10.6084/m9.figshare.22599472.v1","title":"Additional file 1 of Estimation of marginal structural models under irregular visits and unmeasured confounder: calibrated inverse probability weights","publisher":"figshare","resource_type":"JournalArticle"},{"doi":"10.6084/m9.figshare.22599472","title":"Additional file 1 of Estimation of marginal structural models under irregular visits and unmeasured confounder: calibrated inverse probability weights","publisher":"figshare","resource_type":"JournalArticle"}],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-03T22:57:38.193343Z","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,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}