Reporting and interpretation of SF-36 outcomes in randomised trials: systematic review
BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.a3006 (Published 12 January 2009) Cite this as: BMJ 2009;338:a3006
- Despina G Contopoulos-Ioannidis, assistant professor12,
- Anastasia Karvouni, research fellow3,
- Ioanna Kouri, research fellow3,
- John P A Ioannidis, professor34
- 1Department of Paediatrics, University of Ioannina School of Medicine, Ioannina, Greece
- 2Department of Paediatrics, George Washington University, School of Medicine and Health Sciences, Washington, DC, USA
- 3Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Greece
- 4Institute for Clinical Research and Health Policy Studies, Tufts University School of Medicine, Boston, MA, USA
- Correspondence to: J P A Ioannidis, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece jioannid{at}cc.uoi.gr
- Accepted 19 September 2008
Abstract
Objective To determine how often health surveys and quality of life evaluations reach different conclusions from those of primary efficacy outcomes and whether discordant results make a difference in the interpretation of trial findings.
Design Systematic review.
Data sources PubMed, contact with authors for missing information, and author survey for unpublished SF-36 data.
Study selection Randomised trials with SF-36 outcomes (the most extensively validated and used health survey instrument for appraising quality of life) that were published in 2005 in 22 journals with a high impact factor.
Data extraction Analyses on the two composite and eight subdomain SF-36 scores that corresponded to the time and mode of analysis of the primary efficacy outcome.
Results Of 1057 screened trials, 52 were identified as randomised trials with SF-36 results (66 separate comparisons). Only eight trials reported all 10 SF-36 scores in the published articles. For 21 of the 66 comparisons, SF-36 results were discordant for statistical significance compared with the results for primary efficacy outcomes. Of 17 statistically significant SF-36 scores where primary outcomes were not also statistically significant in the same direction, the magnitude of effect was small in six, moderate in six, large in three, and not reported in two. Authors modified the interpretation of study findings based on SF-36 results in only two of the 21 discordant cases. Among 100 additional randomly selected trials not reporting any SF-36 information, at least five had collected SF-36 data but only one had analysed it.
Conclusions SF-36 measurements sometimes produce different results from those of the primary efficacy outcomes but rarely modify the overall interpretation of randomised trials. Quality of life and health related survey information should be utilised more systematically in randomised trials.
Footnotes
We thank the following for clarifying their results or providing additional data: N Assefi, D Buchwald, and C Jacobsen (for Assefi et alw1); A Avenell and JA Cook (for Avenell et alw2); J Carratala, LJ Crofford, J Pepper, and B Lees (for De Arenaza et alw10); H Escobar-Morreale, RM Greenhalgh, and LC Brown (for EVAR 1w14 and EVAR 2w15); I Gilron, S Hewlett, F Hill-Briggs, CA Hukins, P Jellema, and DA van der Windt (for Jellema et alw23); JA Klaber-Moffett, K Linde, PS Parfrey, and RN Foley (for Parfrey et alw31); DJ Torgerson (for Porthouse et alw32); D Revicki and JM Miranda (for Revicki et alw35); M Rienstra and IC van Gelder (for Rienstra et alw36); BL Rollman, MF Scheier, and S Colvin (for Scheier et alw40); N Shaheen, BN Singh, AL Stanton, and G Bleijenberg (for Stulemeijer et alw45); D van der Heijde and JH Stone (for Wegener’s Granulomatosis Etanercept Trialw50); and WA Whitelaw.
Contributors: JPAI conceived the study and is guarantor. All authors designed the protocol, analysed and interpreted the data, and approved the final manuscript. DGC-I, IK, and AK collected the data. DGC-I and JPAI drafted the manuscript. IK and AK critically revised the manuscript for important intellectual content.
Funding: None.
Competing interests: None declared.
Ethical approval: Not required.
Provenance and peer review: Not commissioned; externally peer reviewed.
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