Case mix adjustment of health outcomes, resource use and process indicators in childbirth care: a register-based study.

BACKGROUND: Unwarranted variation in care practice and outcomes has gained attention and inter-hospital comparisons are increasingly being used to highlight and understand differences between hospitals. Adjustment for case mix is a prerequisite for meaningful comparisons between hospitals with different patient populations. The objective of this study was to identify and quantify maternal characteristics that impact a set of important indicators of health outcomes, resource use and care process and which could be used for case mix adjustment of comparisons between hospitals. METHODS: In this register-based study, 139 756 deliveries in 2011 and 2012 were identified in regional administrative systems from seven Swedish regions, which together cover 67 % of all deliveries in Sweden. Data were linked to the Medical birth register and Statistics Sweden's population data. A number of important indicators in childbirth care were studied: Caesarean section (CS), induction of labour, length of stay, perineal tears, haemorrhage > 1000 ml and post-partum infections. Sociodemographic and clinical characteristics deemed relevant for case mix adjustment of outcomes and resource use were identified based on previous literature and based on clinical expertise. Adjustment using logistic and ordinary least squares regression analysis was performed to quantify the impact of these characteristics on the studied indicators. RESULTS: Almost all case mix factors analysed had an impact on CS rate, induction rate and length of stay and the effect was highly statistically significant for most factors. Maternal age, parity, fetal presentation and multiple birth were strong predictors of all these indicators but a number of additional factors such as born outside the EU, body mass index (BMI) and several complications during pregnancy were also important risk factors. A number of maternal characteristics had a noticeable impact on risk of perineal tears, while the impact of case mix factors was less pronounced for risk of haemorrhage > 1000 ml and post-partum infections. CONCLUSIONS: Maternal characteristics have a large impact on care process, resource use and outcomes in childbirth care. For meaningful comparisons between hospitals and benchmarking, a broad spectrum of sociodemographic and clinical maternal characteristics should be accounted for.

School attainment of children who had a single umbilical artery at birth.

To the best of our knowledge, this is the first registry study of school achievements among children born with a single umbilical artery (SUA). A total of 1600 infants born with SUA during 1983-86 were studied. We linked the Swedish Medical Birth Registry with the Swedish School Registry, which contains the school grades of all children in Sweden when leaving compulsory school. Risks were estimated as odds ratios (OR) using the Mantel-Haenzel procedure, after adjustment for four potential confounders: year of birth, maternal age, parity and maternal education. There was a 60% excess of children born with SUA who did not complete compulsory school after removal of infants born preterm, small-for-gestational age and low Apgar score (OR = 1.60 [95% confidence interval 1.28, 2.00]). When sports and the three core school subjects (mathematics, English and Swedish) were studied, there was an increased risk for 'not passed' in all subjects except sport and a slight decrease in the probability of achieving 'passed with distinction or excellence'. In the three core subjects there was an association with gender, boys with SUA being more likely to have 'not passed' than girls. In conclusion the children born with SUA are more likely than children born with three vessels to show impaired school achievements.

Massive feto-maternal hemorrhage: diagnosis by cardiotocography, Doppler ultrasonography and ST waveform analysis of fetal electrocardiography.

A 34-year-old healthy gravida 2 para 1 presented after an uncomplicated pregnancy at term with a 2-day history of diminished fetal movements. Fetal anemia was suspected by fetal heart rate monitoring and Doppler estimation of the fetal peak blood flow velocity of the middle cerebral artery. We were also fortunate to register pathological ST waveform changes of the fetal ECG indicating fetal hypoxia. The diagnosis of a massive feto-maternal hemorrhage was confirmed by an extremely high fraction of erythrocytes containing fetal hemoglobin in maternal blood and, after delivery, by placental histology.