Large differences in obstetrical intervention rates among Dutch hospitals, even after adjustment for population differences.

Within the framework of the 'Obstetric Peer Review' project (Verloskundige Onderlinge Kwaliteitsspiegeling, VOKS) statistical models have been developed to predict department specific intervention rates, based on the distribution of risk factors in each department. Subsequently the difference between the expected number of interventions (labour inductions, caesarean sections and vaginal operative deliveries) and the actual numbers were calculated for each year and subpopulation defined by the level of prematurity. Data used were available from the Perinatal Database of the Netherlands (Landelijke Verloskunde Registratie, LVR) concerning the years 1988-1992.

Trends in caesarean section rates among high- and medium-risk pregnancies in The Netherlands 1983-1992.

During the last two decades, the rates of operative deliveries have been rising constantly in all industrialized countries including the Netherlands. Within the framework of the project 'Obstetric Peer Review' (Verloskundige Onderlinge Kwaliteitsspiegeling), the trends in the caesarean section rates were investigated, using the data of the Perinatal Database of the Netherlands (LVR), but only among the high- and medium-risk pregnancies. To that end homogeneous high-risk subgroups, with respect to pregnancy- or delivery-related complications, were defined in various ways and caesarean section rates were calculated for these groups.

How to compare and report department specific mortality rates for peer review using the Perinatal Database of The Netherlands.

Since characteristics of patient populations of obstetric departments vary substantially with respect to the pathology presented, (perinatal) mortality rates as such can not be used for a fair peer review without adjustment for those differences. Using the Perinatal Database of The Netherlands (LVR), data on approximately 80,000 newborns annually from 1985 to 1991 inclusive were used in statistical models to predict the perinatal mortality risks of four subpopulations of different gestational age in about 125 obstetric departments. As predictors for perinatal mortality we used only those risk factors which were judged to reflect the 'pathology' of the patient; risk factors associated with or resulting from hospital care and/or policy are (by definition) excluded.

Differences in obstetrical intervention rates between Dutch hospitals.

Within the framework of the project 'Obstetric Peer Review' (Verloskundige Onderlinge Kwaliteitsspiegeling, VOKS) differences between Dutch hospitals concerning various obstetrical interventions were investigated. Using data of the Perinatal Database of the Netherlands from hospitals with at least 2000 newborns in the 5-year period 1987-1991, remarkable differences in frequencies of labour induction, caesarean section and vaginal operative deliveries can be shown, even when these interventions were considered within homogeneous subgroups with respect to pregnancy- or delivery-related complications. The incidence of caesarean section (and labour induction and vaginal operative delivery) appeared to depend more on the specific hospital policy than might be explained by populations differences alone.

Estimate of perinatal mortality risk.

Perinatal mortality is usually calculated according to the World Health Organisation as stillbirth and first week mortality at a specified week of gestation divided by all births at that same gestational week. This is not a meaningful indicator of the risk of future perinatal death for a living fetus. We have developed an approach to estimate the prospective risk of perinatal mortality.

Obstetric characteristics profiles as quality assessment of obstetric care.

In The Netherlands only about 50% of all pregnancies are defined as high risk pregnancies and consequently come into the domain of care of an obstetrician. In order to qualify as a high risk pregnancy, the pregnancy must satisfy certain criteria contained in an officially approved list of indications. Due to varying perceptions of these selection criteria by the selectors, larger differences in the treated population, obstetric interventions and results, respectively, were expected than in other countries.