Individual and Organisational Determinants Associated with Maintenance Tocolysis in the Management of Preterm Labour: A Multilevel Analysis

Background: Clinical guidelines do not recommend maintenance tocolysis for the management of preterm labour. The French national survey EVAPRIMA revealed it was administered to more than 50% of women hospitalised for preterm labour. Our aim was to identify the individual and organisational determinants associated with maintenance tocolysis. Methods: The study was a secondary analysis of the prospective population-based EVAPRIMA study database. Population study included every women hospitalised for preterm labour and at risk of receiving maintenance tocolysis, over a one month period, in 99 randomly selected French maternity units. Main outcome was the prescription of maintenance tocolysis. The association between maintenance tocolysis and individual (maternal or obstetrical) and organisational determinants were evaluated with multilevel analysis. Results: Of the 531 women included, 68.9% (95% CI 0.65–0.73) received maintenance tocolysis. The only individual factor associated with maintenance tocolysis was gestational age at admission; the rate of maintenance tocolysis was higher among women hospitalised before 32 weeks of gestation. The significantly different rates between maternity units demonstrated the existence of a maternity unit effect. Maintenance tocolysis was also associated with organisational determinants and was more frequent in level 1 (ORa = 6.54[2.21–19.40]) and level 2 maternity units (ORa = 3.68[1.28–10.59]), in units with less than 1500 deliveries/year (ORa = 5.27[4.43–19.44]), and in specific areas of France. Conclusion: A maternity unit effect, explained partly by the organisational characteristics of the units, plays a major role in the practice of maintenance tocolysis. Widespread dissemination of these results might improve adherence to clinical guidelines.