Consent Rates Reported in Published Pediatric Randomized Controlled Trials.

OBJECTIVE: To determine the average reported consent rate for published pediatric randomized controlled trials (RCTs) and whether this rate varies by trial characteristics. STUDY DESIGN: 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. RESULTS: 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. CONCLUSIONS: 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 Our findings should assist with the planning of future pediatric RCTs, although consent data from unpublished trials are also needed.

Short interpregnancy interval as a risk factor for preterm birth in non-Hispanic Black and White women in California.

OBJECTIVE: Short interpregnancy interval (IPI) is associated with adverse pregnancy outcomes, including preterm birth (PTB < 37 weeks GA). We investigated whether short IPI (< 6 months) contributes to the higher PTB frequency among non-Hispanic Blacks (NHB). STUDY DESIGN: Using a linked birth cohort > 1.5 million California live births, we examined frequencies of short IPI between racial/ethnic groups and estimated risks by multivariable logistic regression for spontaneous PTB. We expanded the study to births 1991-2012 and utilized a "within-mother" approach to permit methodologic inquiry about residual confounding. RESULTS: NHB women had higher frequency (7.6%) of short IPI than non-Hispanic White (NHW) women (4.4%). Adjusted odds ratios for PTB and short IPI were 1.64 (95% CI 1.54, 1.76) for NHW and 1.49 (1.34, 1.65) for NHB. Using within-mother analysis did not produce substantially different results. CONCLUSIONS: Short IPI is associated with PTB but does not explain risk disparity between NHWs and NHBs.