Aggregating and Disaggregating Patients in Clinical Trials and Their Subgroup Analyses
Authors: David M. Kent
Journal: Annals of Internal Medicine (2010)

Editorials6 July 2010Aggregating and Disaggregating Patients in Clinical Trials and Their Subgroup AnalysesDavid M. Kent, MD, MS and Peter K. Lindenauer, MD, MScDavid M. Kent, MD, MSFrom Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA 02111, and Center for Quality of Care Research, Baystate Medical Center, Springfield, MA 01199.Search for more papers by this author and Peter K. Lindenauer, MD, MScFrom Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA 02111, and Center for Quality of Care Research, Baystate Medical Center, Springfield, MA 01199.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-153-1-201007060-00012 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail In this issue, Hull and colleagues (1) report on their trial examining venous thromboembolism (VTE) prophylaxis in medical patients. An interim analysis of this trial, performed after enrollment of more than 3000 patients at 370 sites in 20 countries, found a lower-than-anticipated VTE rate (symptomatic or asymptomatic) in those treated with standard enoxaparin prophylaxis (3.3%). In a different context, one might have expected the trial's sponsor, which markets enoxaparin, to have been pleased. However, because this trial was designed to test extended-duration enoxaparin, these results may not have been a cause for celebration. For new therapies, especially those with risks ...References1. Hull RD, Schellong SM, Tapson VF, Monreal M, Samama MM, Nicol P, et al. Extended-duration venous thromboembolism prophylaxis in acutely ill medical patients with recently reduced mobility. A randomized trial. Ann Intern Med. 2010;153:8-18. LinkGoogle Scholar2. Kent DM, Trikalinos TA. Therapeutic innovations, diminishing returns, and control rate preservation. JAMA. 2009;302:2254-6. [PMID: 19934428] CrossrefMedlineGoogle Scholar3. Glasziou PP, Irwig LM. An evidence based approach to individualising treatment. BMJ. 1995;311:1356-9. [PMID: 7496291] CrossrefMedlineGoogle Scholar4. Kent DM, Hayward RA. Limitations of applying summary results of clinical trials to individual patients: the need for risk stratification. JAMA. 2007;298:1209-12. [PMID: 17848656] CrossrefMedlineGoogle Scholar5. Sun X, Briel M, Walter SD, Guyatt GH. Is a subgroup effect believable? Updating criteria to evaluate the credibility of subgroup analyses. BMJ. 2010;340:c117. [PMID: 20354011] CrossrefMedlineGoogle Scholar6. Rothberg MB, Lahti M, Pekow PS, Lindenauer PK. Venous thromboembolism prophylaxis among medical patients at US hospitals. J Gen Intern Med. 2010;25:489-94. [PMID: 20352366] CrossrefMedlineGoogle Scholar Author, Article, and Disclosure InformationAuthors: David M. Kent, MD, MS; Peter K. Lindenauer, MD, MScAffiliations: From Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA 02111, and Center for Quality of Care Research, Baystate Medical Center, Springfield, MA 01199.Grant Support: In part by the National Center for Research Resources of the National Institutes of Health (grant UL1RR025752) and the National Institute of Neurological Disorders and Stroke (grant R01 NS062153).Disclosures: None disclosed. Forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M10-1096.Corresponding Author: David M. Kent, MD, MS, Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Box 63, 800 Washington Street, Boston, MA 02111; e-mail, dkent1@tuftsmedicalcenter.org.Current Author Addresses: Dr. Kent: Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Box 63, 800 Washington Street, Boston, MA 02111.Dr. Lindenauer: Center for Quality of Care Research, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetailsSee AlsoExtended-Duration Venous Thromboembolism Prophylaxis in Acutely Ill Medical Patients With Recently Reduced Mobility Russell D. Hull , Sebastian M. Schellong , Victor F. Tapson , Manuel Monreal , Meyer-Michel Samama , Philippe Nicol , Eric Vicaut , Alexander G.G. Turpie , and Roger D. Yusen , for the EXCLAIM (Extended Prophylaxis for Venous ThromboEmbolism in Acutely Ill Medical Patients With Prolonged Immobilization) study* Metrics Cited byDigoxin Benefit Varies by Risk of Heart Failure Hospitalization: Applying the Tufts MC HF Risk ModelCaring for patients with kidney disease: shifting the paradigm from evidence-based medicine to patient-centered careBreast cancer and thrombosis: timing mattersVenous Thromboembolism: Deep Vein Thrombosis and Pulmonary EmbolismPredictability of Persistent Frequent Attendance in Primary Care: A Temporal and Geographical Validation StudyEffect of Long-Term LMWH on Post-thrombotic Syndrome in Patients With Iliac/Noniliac Venous ThrombosisMedical PatientsPulmonary EmbolismImpact of age on the efficacy and safety of extended-duration thromboprophylaxis in medical patientsPulmonary embolism and deep vein thrombosisBuilding useful evidence: changing the clinical research paradigm to account for comparative effectiveness researchDo steroids benefit patients with bacterial meningitis? 6 July 2010Volume 153, Issue 1Page: 51-52KeywordsFactor analysisHemorrhageMedical risk factorsProphylaxisRisk managementStatistical dataStrokeTreatment guidelinesVenous thromboembolism ePublished: 6 July 2010 Issue Published: 6 July 2010 Copyright & PermissionsCopyright © 2010 by American College of Physicians. 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