How Much Did Biases in the Study of Chronic Obstructive Pulmonary Disease Medications and Mortality Affect the Outcome?
Authors: Nicholas J. Gross
Journal: Annals of Internal Medicine (2009)

Letters17 March 2009How Much Did Biases in the Study of Chronic Obstructive Pulmonary Disease Medications and Mortality Affect the Outcome?Nicholas J. Gross, MD, PhDNicholas J. Gross, MD, PhDFrom Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-150-6-200903170-00018 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail TO THE EDITOR:Despite its very large data base, the study by Lee and colleagues (1) has problems that are inherent to observational data analyses in which potential confounding factors cannot be reliably controlled for. Of particular concern in their study is the absence of data about disease severity and smoking status, which the authors acknowledge. Attempts to adjust for these confounders by reference to a small pilot study of questionable relevance (2) or by internal “measures of disease severity” that are not described in any detail are not reassuring. When the effect size of a treatment of interest—ipratropium versus ...References1. Lee TA, Pickard AS, Au DH, Bartle B, Weiss KB. Risk for death associated with medications for recently diagnosed chronic obstructive pulmonary disease. Ann Intern Med. 2008;149:380-90. [PMID: 18794557] LinkGoogle Scholar2. Joo MJ, Lee TA, Bartle B, van de Graaff WB, Weiss KB. Patterns of healthcare utilization by COPD severity: a pilot study. Lung. 2008;186:307-12. [PMID: 18463921] CrossrefMedlineGoogle Scholar3. Salpeter SR, Buckley NS. Systematic review of clinical outcomes in chronic obstructive pulmonary disease: beta-agonist use compared with anticholinergics and inhaled corticosteroids. Clin Rev Allergy Immunol. 2006;31:219-30. [PMID: 17085795] CrossrefMedlineGoogle Scholar4. Ringbaek T, Viskum K. Is there any association between inhaled ipratropium and mortality in patients with COPD and asthma? Respir Med. 2003;97:264-72. [PMID: 12645834] CrossrefMedlineGoogle Scholar Author, Article, and Disclosure InformationAffiliations: From Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153.Disclosures:Consultancies: Boehringer Ingelheim, GlaxoSmithKline, Altana, Almirall, Forest, Dey, AstraZeneca. Honoraria: AstraZeneca, Boehringer Ingelheim, Dey, Pfizer. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetailsSee AlsoRisk for Death Associated with Medications for Recently Diagnosed Chronic Obstructive Pulmonary Disease Todd A. Lee , A. Simon Pickard , David H. Au , Brian Bartle , and Kevin B. Weiss How Much Did Biases in the Study of Chronic Obstructive Pulmonary Disease Medications and Mortality Affect the Outcome? Takeharu Koga , Tomoko Kamimura , and Munetsugu Nishimura How Much Did Biases in the Study of Chronic Obstructive Pulmonary Disease Medications and Mortality Affect the Outcome? Todd A. Lee , A. Simon Pickard , and David H. Au How Much Did Biases in the Study of Chronic Obstructive Pulmonary Disease Medications and Mortality Affect the Outcome? Samy Suissa and Pierre Ernst Metrics 17 March 2009Volume 150, Issue 6Page: 426KeywordsDiureticsFactor analysisHypertensionMedical risk factorsOsteoarthritisPatientsPilot studiesProspective studies ePublished: 17 March 2009 Issue Published: 17 March 2009 Copyright & PermissionsCopyright © 2009 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...