Full Publication of Clinical Trials Presented at a National Maternal-Fetal Medicine Meeting: Is There a Publication Bias?

ABSTRACT

We sought to determine the rate and timing of full publication of clinical trials initially presented as abstracts at a national maternal-fetal medicine (MFM) research meeting and identify factors associated with publication status. All abstracts presented over a 3-year period (2000 to 2002) at the Society of MFM Annual Meeting were reviewed. Abstracts reporting outcomes for prospective, interventional research studies with human subjects were included. Multiple electronic databases were searched for evidence of full publication with a minimum of 5-year follow-up. The reporting characteristics of abstracts that were published as full research reports were compared with those not published. During the study period, 2012 abstracts were presented and 90 met all study criteria (4.5%). Of these, 55.6% (n = 50) were subsequently published as full research reports. There were no differences in the use of placebo, randomization, or blinding. Studies reaching full publication had larger sample size (median 174 [12 to 4165] versus 96 [22 to 1039]; p = 0.02) and were more likely to report treatment differences (60% versus 32.5% p = 0.009). After adjusting for confounding factors, the reporting of treatment differences remained associated with full publication (odds ratio 3.3 [95% confidence interval 1.3 to 8.0]; p = 0.01). Full publication of clinical trials occurred more often if treatment differences were present. Positive publication bias exists in MFM research.

KEYWORDS

Publication bias - clinical trial - maternal-fetal medicine - reporting - abstract

REFERENCES

• 1 Dickersin K. The existence of publication bias and risk factors for its occurrence.  JAMA. 1990;  263 1385-1389
• 2 Dickersin K. How important is publication bias? A synthesis of available data.  AIDS Educ Prev. 1997;  9 15-21
• 3 Solomon P, Hutton J. Meta-analysis, overviews and publication bias.  Stat Methods Med Res. 2001;  10 245-250
• 4 Song F, Eastwood A J, Gilbody S, Duley L, Sutton A J. Publication and related biases.  Health Technol Assess. 2000;  4 1-115
• 5 Begg C B, Berlin J A. Publication bias and dissemination of clinical research.  J Natl Cancer Inst. 1989;  81 107-115
• 6 Egger M, Smith G D. Misleading meta-analysis.  BMJ. 1995;  310 752-754
• 7 Chalmers I. Underreporting research is scientific misconduct.  JAMA. 1990;  263 1405-1408
• 8 Gilbert W M, Pitkin R M. Society for Maternal–Fetal Medicine meeting presentations: what gets published and why?.  Am J Obstet Gynecol. 2004;  191 32-35
• 9 Scherer R W, Langenberg P, von Elm E. Full publication of results initially presented in abstracts.  Cochrane Database Syst Rev. 2007;  MR000005
• 10 Hopewell S, Clarke M, Stewart L, Tierney J. Time to publication for results of clinical trials.  Cochrane Database Syst Rev. 2007;  MR000011
• 11 Ioannidis J P. Effect of the statistical significance of results on the time to completion and publication of randomized efficacy trials.  JAMA. 1998;  279 281-286
• 12 Dwan K, Altman D G, Arnaiz J A et al.. Systematic review of the empirical evidence of study publication bias and outcome reporting bias.  PLoS One. 2008;  3 e3081
• 13 Song F, Eastwood A, Gilbody S, Duley L. The role of electronic journals in reducing publication bias.  Med Inform Internet Med. 1999;  24 223-229
• 14 Chalmers T C, Frank C S, Reitman D. Minimizing the three stages of publication bias.  JAMA. 1990;  263 1392-1395
• 15 Meinert C L. Toward prospective registration of clinical trials.  Control Clin Trials. 1988;  9 1-5