Change in care among nonenrolled patients during and after a randomized trial

Abstract

Objective: Parkland Memorial Hospital (PMH) participated in Surfactant, Positive Pressure, and Oxygenation Randomized Trial (SUPPORT), an unblinded controlled trial, in which preterm neonates of 24(0/7) to 27(6/7) weeks' gestational age (GA) were randomized in the delivery room (DR) to endotracheal intubation or nasal continuous positive airway pressure. We hypothesized that DR intubation could change in nonenrolled patients at PMH and that the change would be larger than in comparable centers not participating in the trial.

Methods: The PMH Cohort included eligible but nonenrolled neonates of 24(0/7) to 27(6/7) weeks (primary) and noneligible neonates of 28 to 34(6/7) weeks (confirmatory). A subset (24(0/7)-29(6/7)weeks) of that cohort was compared with a contemporaneous cohort born in centers participating in the Vermont Oxford Network (VON). We used a Poisson regression model to obtain adjusted relative risks (RRs) of DR intubation (during/after SUPPORT versus before SUPPORT) for PMH and for VON along with the ratio of these RRs.

Results: In the PMH cohort (n = 3527), the proportion of DR intubation decreased during/after SUPPORT in the lower GA group (adjusted RR 0.76, 95% confidence interval [CI] 0.59-0.96) and the upper GA group (adjusted RR 0.57, 95% CI 0.46-0.70). Compared with the RR for DR intubation in VON, the RR at PMH was smaller in the lower (ratio of RR 0.76, 95% CI 0.65-0.87) and the upper GA group (ratio of RR 0.52, 95% CI 0.39-0.68).

Conclusions: A center's participation in an unblinded randomized trial may affect process of care of nonenrolled patients.

Keywords: birth cohort study; endotracheal intubation; non-enrolled patients; preterm; process of care; randomized controlled trial; unblinded.