Instrumental Variable Analyses for Observational Comparative Effectiveness Research: The Paired Availability Design
Authors: Laura Faden Garabedian, Alan M. Zaslavsky, Stephen B. Soumerai
Journal: Annals of Internal Medicine (2014)

Letters2 December 2014Instrumental Variable Analyses for Observational Comparative Effectiveness Research: The Paired Availability DesignLaura Faden Garabedian, PhD, Alan M. Zaslavsky, PhD, and Stephen B. Soumerai, ScDLaura Faden Garabedian, PhDFrom Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this author, Alan M. Zaslavsky, PhDFrom Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this author, and Stephen B. Soumerai, ScDFrom Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/L14-5029-2 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail IN RESPONSE:Drs. Baker and Lindeman question our omission of time period as a potential instrumental variable for comparative effectiveness research. Our study focused on the 4 most commonly used instruments in this research. However, we did acknowledge the potential for time-based instruments by stating, “The assumption that the instrument is only related to the outcome through the treatment may apply best to specific, focused, plausibly exogenous interventions or events, such as natural experiments (for example, the Oregon Medicaid lottery [1] or changes in policy or technology [2]).” The PAD studies cited by Drs. Baker and Lindeman did not explicitly ...References1. Baicker K, Taubman SL, Allen HL, Bernstein M, Gruber JH, Newhouse JP, et al; Oregon Health Study Group. The Oregon experiment—effects of Medicaid on clinical outcomes. N Engl J Med. 2013;368:1713-22. [PMID: 23635051] doi:10.1056/NEJMsa1212321 CrossrefMedlineGoogle Scholar2. Angrist JD, Krueger AB. Instrumental variables and the search for identification: from supply and demand to natural experiments. J Econ Perspect. 2001;15:69-85. CrossrefGoogle Scholar3. Baker SG, Lindeman KS, Kramer BS. The paired availability design for historical controls. BMC Med Res Methodol. 2001;1:9. [PMID: 11602018] CrossrefMedlineGoogle Scholar4. Brookhart MA, Rassen JA, Schneeweiss S. Instrumental variable methods in comparative safety and effectiveness research. Pharmacoepidemiol Drug Saf. 2010;19:537-54. [PMID: 20354968] doi:10.1002/pds.1908 CrossrefMedlineGoogle Scholar5. Wagner AK, Soumerai SB, Zhang F, Ross-Degnan D. Segmented regression analysis of interrupted time series studies in medication use research. J Clin Pharm Ther. 2002;27:299-309. [PMID: 12174032] CrossrefMedlineGoogle Scholar Author, Article, and Disclosure InformationAuthors: Laura Faden Garabedian, PhD; Alan M. Zaslavsky, PhD; Stephen B. Soumerai, ScDAffiliations: From Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Disclosures: Disclosures can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M13-1887. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetailsSee AlsoPotential Bias of Instrumental Variable Analyses for Observational Comparative Effectiveness Research Laura Faden Garabedian , Paula Chu , Sengwee Toh , Alan M. Zaslavsky , and Stephen B. Soumerai Potential Bias of Instrumental Variable Analyses for Observational Comparative Effectiveness Research Laura Faden Garabedian , Paula Chu , Sengwee Toh , Alan M. Zaslavsky , and Stephen B. Soumerai Instrumental Variable Analyses for Observational Comparative Effectiveness Research: The Paired Availability Design Stuart G. Baker and Karen S. Lindeman Instrumental Variable Analyses for Observational Comparative Effectiveness Research: The Paired Availability Design Stuart G. Baker and Karen S. Lindeman Metrics Cited byWhat to do (or not to do) when randomization is not possibleFollow Your Heart: Survival Chances and Costs after Heart Attacks-An Instrumental Variable Approach 2 December 2014Volume 161, Issue 11Page: 841KeywordsBehaviorComparative effectiveness researchDisclosureInstrumental variable analysisPlagueResearch design ePublished: 2 December 2014 Issue Published: 2 December 2014 Copyright & PermissionsCopyright © 2014 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...