You are seeing this message because your Web browser does not support basic Web standards. Find out more about why this message is appearing and what you can do to make your experience on this site better.


ABOUT JAMA
Advanced Search

Welcome   | My Account | E-mail Alerts | Access Rights | Sign In


  Vol. 297 No. 3, January 17, 2007 TABLE OF CONTENTS
  JAMA
  •  Online Features
  Editorial
 This Article
 •Full text
 •PDF
 •Send to a friend
 • Save in My Folder
 •Save to citation manager
 •Permissions
 Citing Articles
 •Citation map
 •Citing articles on HighWire
 •Citing articles on ISI (22)
 •Contact me when this article is cited
 Related Content
 •Related letters
 •Related article
 •Similar articles in JAMA
 Topic Collections
 •Statistics and Research Methods
 •Alert me on articles by topic

Estimating Treatment Effects Using Observational Data

Ralph B. D’Agostino, Jr, PhD; Ralph B. D’Agostino, Sr, PhD

JAMA. 2007;297:314-316.

Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.

The randomized clinical trial (RCT) is the ideal method for measuring treatment effects. Participants in clinical trials are randomly assigned to a treatment or control group. Randomization reduces biases by making treatment and control groups "equal with respect to all features," except the treatment assignment. When randomization is performed correctly, differences in efficacy found by statistical comparisons can be attributed to the difference between the treatment and control.1

However, the RCT does not necessarily provide the final answer to treatment effectiveness, as there are many restrictions that limit generalizability. For example, RCTs are often restricted to patients with limited disease, comorbidity, and concomitant medications. Thus, RCTs generally demonstrate efficacy rather than effectiveness, where efficacy is the treatment effect under the restricted conditions of the RCT and effectiveness is the treatment effect under the conditions of usual practice.1

Observational, nonrandomized studies . . . [Full Text of this Article]

Author Affiliations: Department of Biostatistical Sciences, Wake Forest University School of Medicine, Winston Salem, NC (Dr D’Agostino, Jr); and Department of Mathematics and Statistics, Boston University, and Harvard Clinical Research Institute, Boston, Mass (Dr D’Agostino, Sr).


RELATED LETTERS

Using Observational Data to Estimate Treatment Effects
Therese A. Stukel, Elliott S. Fisher, and David E. Wennberg
JAMA. 2007;297(19):2078-2079.
EXTRACT | FULL TEXT  

Using Observational Data to Estimate Treatment Effects—Reply
Ralph B. D’Agostino, Jr and Ralph B. D’Agostino, Sr
JAMA. 2007;297(19):2079.
EXTRACT | FULL TEXT  

RELATED ARTICLE

Analysis of Observational Studies in the Presence of Treatment Selection Bias: Effects of Invasive Cardiac Management on AMI Survival Using Propensity Score and Instrumental Variable Methods
Thérèse A. Stukel, Elliott S. Fisher, David E. Wennberg, David A. Alter, Daniel J. Gottlieb, and Marian J. Vermeulen
JAMA. 2007;297(3):278-285.
ABSTRACT | FULL TEXT  


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

IS IT TIME TO USE OBSERVATIONAL DATA TO ESTIMATE TREATMENT EFFECTIVENESS IN MULTIPLE SCLEROSIS?
Wilkins and Trojano
Neurology 2008;71:463-464.
FULL TEXT  

Randomized Clinical Trials and Observational Studies: Guidelines for Assessing Respective Strengths and Limitations
Hannan
J Am Coll Cardiol Intv 2008;1:211-217.
ABSTRACT | FULL TEXT  

Effects of LifeSkills Training on Medical Students' Performance in Dealing with Complex Clinical Cases
Campo et al.
Acad. Psychiatry 2008;32:188-193.
ABSTRACT | FULL TEXT  

Evidence from Nonrandomized Studies: A Case Study on the Estimation of Causal Effects
Schmoor et al.
Am J Epidemiol 2008;167:1120-1129.
ABSTRACT | FULL TEXT  

Fall-Related Hospitalization and Facility Costs Among Residents of Institutions Providing Long-Term Care
Carroll et al.
Gerontologist 2008;48:213-222.
ABSTRACT | FULL TEXT  

"Off-label" stent therapy 2-year comparison of drug-eluting versus bare-metal stents.
Applegate et al.
J Am Coll Cardiol 2008;51:607-614.
ABSTRACT | FULL TEXT  

Assessing the safety of drugs through observational research
Simpson
Heart 2008;94:129-130.
FULL TEXT  

Drug-Eluting Stents vs. Coronary-Artery Bypass Grafting in Multivessel Coronary Disease
Hannan et al.
NEJM 2008;358:331-341.
ABSTRACT | FULL TEXT  

Analytic Approaches to Observational Studies With Treatment Selection Bias
Novikov and Kalter-Leibovici
JAMA 2007;297:2077-2077.
FULL TEXT  

Using Observational Data to Estimate Treatment Effects
Stukel et al.
JAMA 2007;297:2078-2079.
FULL TEXT  

Observational studies should carry a health warning
BMJ 2007;334:179-179.
FULL TEXT  





HOME | CURRENT ISSUE | PAST ISSUES | TOPIC COLLECTIONS | CME | SUBMIT | SUBSCRIBE | HELP
CONDITIONS OF USE | PRIVACY POLICY | CONTACT US | SITE MAP
 
© 2007 American Medical Association. All Rights Reserved.