[Enriched-enrollment randomized-withdrawal trials]. / Contribution de la Société francophone de recherche en pédiatrie: les essais randomisés d'interruption du traitement après enrichissement de population.

A clinical trial's power depends on the probability of observing an effect of the tested drug in the trial population, on the size of this effect, and on the heterogeneousness of the judgment criterion in the population. Enriched-enrollment randomized-withdrawal trials are clinical trials which comprise a first period in which subjects are selected depending on whether they respond to the tested drug or not. The responding patients are subsequently randomized into 2 groups: in one of them the treatment is pursued, in the other group a placebo is substituted. These designs are very useful in pediatrics, decreasing the number of subjects needed, on condition that the effect of the treatment is only suspensive in a setting of chronic disease. Here we discuss the advantages and disadvantages of such trials.

Identification of factors influencing the decision-to-delivery interval in emergency caesarean sections.

BACKGROUND: In a life-threatening context, the American College of Obstetrics and Gynecology and the Royal College of Obstetrics and Gynaecology recommend a maximum delay of 30 min between the decision to perform an emergency caesarean and the infant's birth. Our objectives were to estimate the rate of prolonged intervals and identify the factors influencing the decision-to-delivery interval. METHODS: All women who had given birth at Saint-Etienne University Hospital by a non-prophylactic caesarean section between September 1 and November 1, 2007 were included in a prospective cohort study. A linear regression analysis was performed to identify the factors influencing the decision-to-delivery interval. RESULTS: 68 women were included in the study. Regardless of the degree of emergency, the decision-to-delivery interval exceeded the recommended interval in 50% of the cases. In extremely urgent caesarean sections, the optimal interval of 15 min was exceeded in 85.7% of cases. We found that two factors contributed to delayed patient care: urgent and extremely urgent caesareans and hospitalization in a pathological pregnancy unit. This delay leads to more paediatric reanimations. CONCLUSION: This study highlights the difficulty to reach the recommended target interval. One solution is to improve the identification of the degree of urgency and the communication between the various members of the healthcare team.