To determine the average reported consent rate for published pediatric randomized controlled trials (RCTs) and whether this rate varies by trial characteristics.

A review of pediatric RCTs published in Medline in 2009, 2010, or 2015 was performed. Secondary analyses of prior trials, trials including adults, trials not requiring consent, or trials with missing or unclear consent data were excluded. Consent rate was defined as the number of patients enrolled divided by number of eligible patients where families were approached. Random effects meta-regression was conducted to determine the weighted average consent rate.

Of 2347 trials identified, 1651 were excluded. An additional 418 of 696 (60%) were excluded because the consent rate was missing or unclear. The average consent rate for 278 included RCTs was 82.6% (95% CI, 80.3%-84.8%) and was higher for vaccination compared with behavioral trials and for industry-funded compared with National Institutes of Health-funded or other government-funded trials. The average consent rate was <70% for 26% of included trials. Of these trials, US trials (28/77 [36.4%]) had a higher probability of a consent rate of <70% than non-US studies (35/64 [21.3%]) and multinational (9/37 [24.3%]) studies. There was slight variation by funding category.

Although the average consent rate for published trials was reasonably high, approximately one-quarter of trials had consent rates of <70%. Consent rates reporting has improved over time, but remains suboptimal. Our findings should assist with the planning of future pediatric RCTs, although consent data from unpublished trials are also needed.