1 The National Perinatal Epidemiology Unit, Radcliffe Infirmary, Oxford, England, and The Johns Hopkins University, School of Hygiene and Public Health, Baltimore, Maryland
Investigations in which statistically significant differences between treatment groups have not been observed are less likely than others to be reported in scientific journals. In clinical research, this selective suppression of "negative" results may lead to the adoption of ineffective or hazardous treatments. In an attempt to obtain information about unpublished trials in perinatal medicine, letters were sent to 42 000 obstetricians and pediatricians in 18 countries. As a result, we were notified of 395 unpublished randomized trials. Only 18 of the trials had been completed more than 2 years before the survey, a period during which at least 2300 reports of perinatal trials had been published. Of the 395 unpublished trials, 125 had ceased recruitment within the 2 years prior to the survey, 193 were actively recruiting at the time of the survey, and 59 were about to begin recruitment. It was concluded that publication bias will not be addressed successfully by attempts to obtain information about unpublished trials retrospectively. However, since the response rate to our request for details about ongoing and planned trials was good, prospective registration of trials at inception appears to be a feasible approach to reducing publication bias and its adverse consequences. An additional merit of prospective registration of clinical trials is that it should reduce unnecessary duplication (as opposed to necessary replication) in research and promote more effective collaboration.
Key Words: unpubliahed controlled trial publication bias controlled trial regiatration perinatal trial
Submitted on November 15, 1988
Accepted on February 8, 1989
This article has been cited by other articles:
![]() |
J. R. Lynch, M. R.A. Cunningham, W. J. Warme, D. C. Schaad, F. M. Wolf, and S. S. Leopold Commercially Funded and United States-Based Research Is More Likely to Be Published; Good-Quality Studies with Negative Outcomes Are Not J. Bone Joint Surg. Am., May 1, 2007; 89(5): 1010 - 1018. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Chalmers From optimism to disillusion about commitment to transparency in the medico-industrial complex J R Soc Med, July 1, 2006; 99(7): 337 - 341. [Full Text] [PDF] |
||||
![]() |
M Bonati and C Pandolfini Trial registration, the ICMJE statement, and paediatric journals Arch. Dis. Child., January 1, 2006; 91(1): 93 - 93. [Full Text] [PDF] |
||||
![]() |
S. Cure, W. L. Chua, L. Duggan, and C. Adams Randomised controlled trials relevant to aggressive and violent people, 1955-2000: a survey The British Journal of Psychiatry, March 1, 2005; 186(3): 185 - 189. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Dickersin, B. R Davis, D. O Dixon, S. L George, B. S Hawkins, J. Lachin, P. Peduzzig, and S. Pocock The Society for Clinical Trials supports United States legislation mandating trials registration Clinical Trials, October 1, 2004; 1(5): 417 - 420. [Abstract] [PDF] |
||||
![]() |
L. Hartling, W. R. Craig, K. Russell, K. Stevens, and T. P. Klassen Factors Influencing the Publication of Randomized Controlled Trials in Child Health Research Arch Pediatr Adolesc Med, October 1, 2004; 158(10): 983 - 987. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Dickersin and D. Rennie Registering Clinical Trials JAMA, July 23, 2003; 290(4): 516 - 523. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Manheimer and D. Anderson Survey of public information about ongoing clinical trials funded by industry: evaluation of completeness and accessibility BMJ, September 7, 2002; 325(7363): 528 - 531. [Abstract] [Full Text] [PDF] |
||||
![]() |
A.-B. Haidich and J. P. A. Ioannidis Effect of Early Patient Enrollment on the Time to Completion and Publication of Randomized Controlled Trials Am. J. Epidemiol., November 1, 2001; 154(9): 873 - 880. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. F. Stroup, J. A. Berlin, S. C. Morton, I. Olkin, G. D. Williamson, D. Rennie, D. Moher, B. J. Becker, T. A. Sipe, S. B. Thacker, et al. Meta-analysis of Observational Studies in Epidemiology: A Proposal for Reporting JAMA, April 19, 2000; 283(15): 2008 - 2012. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Rennie Fair Conduct and Fair Reporting of Clinical Trials JAMA, November 10, 1999; 282(18): 1766 - 1768. [Full Text] [PDF] |
||||
![]() |
P. D. Walson Patient Recruitment: US Perspective Pediatrics, September 1, 1999; 104(3): 619 - 622. [Abstract] [Full Text] |
||||
![]() |
J. P. A. Ioannidis Effect of the Statistical Significance of Results on the Time to Completion and Publication of Randomized Efficacy Trials JAMA, January 28, 1998; 279(4): 281 - 286. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Sakala The Cochrane Pregnancy and Childbirth Database: Implications for Perinatal Care Policy and Practice in the United States Eval Health Prof, December 1, 1995; 18(4): 428 - 466. [Abstract] [PDF] |
||||
![]() |
D. Indyk and D. A. Rier Grassroots AIDS Knowledge: Implications for the Boundaries of Science and Collective Action Science Communication, September 1, 1993; 15(1): 3 - 43. [Abstract] |
||||