In this article, we have focused our attention on the obstetric
care in hospitals and, more specifically, on the quality and safety of care outside office hours. Materials and methods The nationwide data for this study has been provided by the Netherlands Perinatal Registry (PRN). This PRN data collection is obtained through a validated TSA coupling of three different registries: the midwifery registry (LVR1), the obstetrics registry (LVR2) and the neonatology registry (LNR).15 The PRN registry covers approximately 95% of all births in the Netherlands. Model of the obstetric care system The descriptive model of the obstetric care system we have developed as part of our study is based on the categorisation of individual professional organisational contexts and related patients (records). In the most detailed view of the model, the subsystems (and related subpopulations) correspond to the distinct context-categories and related patient groups.12 The more global model presented in this article has been obtained by merging a number of context-categories and related patient groups (figure 1). Determiners of the main (merged) context-categories and related patient groups are the supervision of labour and the location of birth. In this global representation
of the model we distinguish non-teaching hospitals, teaching hospitals (obstetrics and gynaecology) and teaching hospitals with a NICU. On the basis of the current timetables in healthcare, we made a distinction between the individual professional organisational contexts
in the daytime (9:00 to 16:00) and the contexts during the evening and night (19:00 to 6:00). To establish as distinct a contrast as possible between the subgroups related to both these context categories, we have defined a third part of the day (category) for the contexts during the intermediate duty Dacomitinib handovers in the early morning and the late afternoon. To mark the time of childbirth, we have used the onset of the second stage, the phase of labour immediately prior to birth. In this phase high demands are placed on the professional organisational context. Transversal and longitudinal comparisons In our study approach we do not restrict ourselves to a transversal comparison of the incidence of adverse outcomes in different context related patient groups, but combine this approach with the visualisation of developments in successive time periods.16 Considering that professional organisational contexts are constantly subject to change, we have chosen time periods of a limited number of calendar years.