Open Access Open Badges Correspondence

A descriptive analysis of a representative sample of pediatric randomized controlled trials published in 2007

Michele P Hamm1, Lisa Hartling1*, Andrea Milne1, Lisa Tjosvold1, Ben Vandermeer1, Denise Thomson1, Sarah Curtis123 and Terry P Klassen4

Author Affiliations

1 Alberta Research Centre for Health Evidence, Department of Pediatrics, University of Alberta. Edmonton, Canada

2 Division of Pediatric Emergency Medicine, Department of Pediatrics, University of Alberta. Edmonton, Canada

3 Women and Children's Health Research Institute, University of Alberta. Edmonton, Canada

4 Manitoba Institute of Child Health, Winnipeg, Canada

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BMC Pediatrics 2010, 10:96  doi:10.1186/1471-2431-10-96

Published: 22 December 2010



Randomized controlled trials (RCTs) are the gold standard for trials assessing the effects of therapeutic interventions; therefore it is important to understand how they are conducted. Our objectives were to provide an overview of a representative sample of pediatric RCTs published in 2007 and assess the validity of their results.


We searched Cochrane Central Register of Controlled Trials using a pediatric filter and randomly selected 300 RCTs published in 2007. We extracted data on trial characteristics; outcomes; methodological quality; reporting; and registration and protocol characteristics. Trial registration and protocol availability were determined for each study based on the publication, an Internet search and an author survey.


Most studies (83%) were efficacy trials, 40% evaluated drugs, and 30% were placebo-controlled. Primary outcomes were specified in 41%; 43% reported on adverse events. At least one statistically significant outcome was reported in 77% of trials; 63% favored the treatment group. Trial registration was declared in 12% of publications and 23% were found through an Internet search. Risk of bias (ROB) was high in 59% of trials, unclear in 33%, and low in 8%. Registered trials were more likely to have low ROB than non-registered trials (16% vs. 5%; p = 0.008). Effect sizes tended to be larger for trials at high vs. low ROB (0.28, 95% CI 0.21,0.35 vs. 0.16, 95% CI 0.07,0.25). Among survey respondents (50% response rate), the most common reason for trial registration was a publication requirement and for non-registration, a lack of familiarity with the process.


More than half of this random sample of pediatric RCTs published in 2007 was at high ROB and three quarters of trials were not registered. There is an urgent need to improve the design, conduct, and reporting of child health research.