Studies Using Randomized Trial Data to Compare Nonrandomized Exposures
Authors: Catharine B. Stack, Anne R. Meibohm, Joshua M. Liao, Eliseo Guallar
Journal: Annals of Internal Medicine (2020)

Understanding Clinical Research7 April 2020Studies Using Randomized Trial Data to Compare Nonrandomized ExposuresCatharine B. Stack, PhD, Anne R. Meibohm, PhD, Joshua M. Liao, MD, MSc, and Eliseo Guallar, MD, DrPHCatharine B. Stack, PhDAmerican College of Physicians, Philadelphia, Pennsylvania (C.B.S., A.R.M.)Search for more papers by this author, Anne R. Meibohm, PhDAmerican College of Physicians, Philadelphia, Pennsylvania (C.B.S., A.R.M.)Search for more papers by this author, Joshua M. Liao, MD, MScUniversity of Washington School of Medicine, Seattle, Washington (J.M.L.)Search for more papers by this author, and Eliseo Guallar, MD, DrPHJohns Hopkins Bloomberg School of Public Health and Johns Hopkins School of Medicine, Baltimore, Maryland (E.G.)Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/M20-0071 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail Researchers frequently use data collected in randomized controlled trials to target questions that are beyond the scope of the original trial. For example, trial data may be used to explore the effects on outcomes of an exposure collected during the trial that was not the randomized intervention. Although such data originate from a randomized trial, the analyses do not have the protection from bias that randomization provides. Successful randomization tends to balance observed and unobserved characteristics between study groups. Comparisons of nonrandomized exposures, even when done using trial data, can be biased and require analytic approaches commonly used for observational ...References1. Hernán MA, Hernández-Díaz S, Robins JM. Randomized trials analyzed as observational studies. Ann Intern Med. 2013;159:560-2. [PMID: 24018844]. doi:10.7326/0003-4819-159-8-201310150-00709 LinkGoogle Scholar2. Rigotti NA, Tindle HA, Regan S, et al. A post-discharge smoking-cessation intervention for hospital patients: Helping HAND 2 randomized clinical trial. Am J Prev Med. 2016;51:597-608. [PMID: 27647060] doi:10.1016/j.amepre.2016.04.005 CrossrefMedlineGoogle Scholar3. Rigotti NA, Chang Y, Tindle HA, et al. Association of e-cigarette use with smoking cessation among smokers who plan to quit after a hospitalization. A prospective study. Ann Intern Med. 2018;168:613-20. 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Observational epidemiology within randomized clinical trials: getting a lot for (almost) nothing. Prog Cardiovasc Dis. 2012;54:367-71. [PMID: 22226006] doi:10.1016/j.pcad.2011.08.003 CrossrefMedlineGoogle Scholar Author, Article, and Disclosure InformationAffiliations: American College of Physicians, Philadelphia, Pennsylvania (C.B.S., A.R.M.)University of Washington School of Medicine, Seattle, Washington (J.M.L.)Johns Hopkins Bloomberg School of Public Health and Johns Hopkins School of Medicine, Baltimore, Maryland (E.G.)Disclosures: Disclosures can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M20-0071.Corresponding Author: Anne R. Meibohm, PhD, American College of Physicians, 190 N. Independence Mall West, Philadelphia, PA 19106; e-mail, [email protected]org.Current Author Addresses: Dr. Stack: Jazz Pharmaceuticals, 2005 Market Street, Suite 2100, Philadelphia, PA 19103.Dr. Meibohm: American College of Physicians, 190 N. Independence Mall West, Philadelphia, PA 19106.Dr. Liao: University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA 98115.Dr. Guallar: Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Room 2-645, Baltimore, MD 21205.Author Contributions: Conception and design: C.B. Stack, A.R. Meibohm, J.M. Liao.Drafting of the article: C.B. Stack, A.R. Meibohm, J.M. Liao.Critical revision of the article for important intellectual content: C.B. Stack, A.R. Meibohm, J.M. Liao, E. Guallar.Final approval of the article: C.B. Stack, A.R. Meibohm, J.M. Liao, E. Guallar.Statistical expertise: C.B. Stack, A.R. Meibohm, E. Guallar.This article was published at Annals.org on 17 March 2020. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byA Narrative Review of Methods for Causal Inference and Associated Educational ResourcesEpidural Steroids for Degenerative Spondylolisthesis: Good, Bad, or Indifferent? 7 April 2020Volume 172, Issue 7Page: 492-494KeywordsCarbon monoxideClinical epidemiologyDisclosureFactor analysisNicotineObservational studiesPrevention, policy, and public healthRandomized trialsSalivaSmoking cessation ePublished: 17 March 2020 Issue Published: 7 April 2020 Copyright & PermissionsCopyright © 2020 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...