Skip Navigation


Rheumatology Advance Access originally published online on June 24, 2008
Rheumatology 2008 47(9):1367-1372; doi:10.1093/rheumatology/ken230
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
47/9/1367    most recent
ken230v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Yuen, S. Y.
Right arrow Articles by Pope, J. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yuen, S. Y.
Right arrow Articles by Pope, J. E.
Related Collections
Right arrow Systemic Lupus Erythematosus and Autoimmunity
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2008. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Learning from past mistakes: assessing trial quality, power and eligibility in non-renal systemic lupus erythematosus randomized controlled trials

S. Y. Yuen and J. E. Pope

The University of Western Ontario, London, Ontario, Canada.

Correspondence to: J. E. Pope, St Joseph's Health Care London, 268 Grosvenor Street, Box 5777, London, ON N6A 4V2, Canada. E-mail: janet.pope{at}sjhc.london.on.ca


  Abstract

Objectives. To evaluate the post hoc study power of randomized controlled trials (RCTs) in the treatment of non-renal SLE and to determine the generalizability of these RCTs using an SLE database.

Methods. RCTs in non-renal SLE were identified using PubMed (1975–2007). Inclusion/exclusion criteria, trial quality (5-point scale) and results of each study were recorded. The inclusion/exclusion criteria were compared with an SLE database to determine the proportion of patients from the database who would theoretically be eligible for these trials. For each negative study, we calculated the post hoc study power. We also looked for temporal improvements of trials in the literature and examined if pharmaceutical involvement influenced trial quality.

Results. Sixty-four articles were included; the mean power of 30 negative studies was 24.6 ± S.E.M. 3.9% (range 2.5–81.1%). Only one study had a power > 80%. Overall, potential eligibility of SLE patients in the database was 45.1 ± S.E.M. 3.6%. Only 14 studies (21.9%) were of good quality. Fortunately, RCT quality is improving over time (trials <1995, compared with 1996–2002 and >2003; P < 0.001). Trials with pharmaceutical involvement had a significantly higher number of enrollees and better study quality.

Conclusions. Negative RCTs in SLE were mostly underpowered but the generalizability of these trials was high. Determination of study power and the impact of eligibility criteria on generalizability of study results are crucial in the design of clinical trials to ensure applicability to clinical practice.

KEY WORDS: Systemic lupus erythematosus, Randomized controlled trial, Study power, Generalizability, Trial quality

Submitted 12 September 2007; revised version accepted 20 May 2008.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.