The accuracy of reporting of general anaesthesia for childbirth: a validation study

Administrative population health data, such as hospital discharge data, are a potentially valuable resource for determining anaesthesia and analgesia use in childbirth at a population level. However the reliability of general anaesthesia reporting is unknown. This study aimed to determine the accuracy of the reporting of peripartum general anaesthesia in single and linked population health data. Data from a statewide validation study of 1200 women provided the gold standard for delivery and postpartum general anaesthesia use. The validation data were merged with both the hospital discharge and birth databases. As both of these datasets collect information on general anaesthesia, it could be reported in one, both or neither database. Among the 1184 records available for review, 7.7% of women had a general anaesthetic during the birth admission, of which 6.2% were for delivery and 1.5% were for a postpartum procedure. Reporting sensitivities ranged from 26% to 97% and specificities 94% to 100%. Identifying general anaesthesia from either the birth or hospital data improved general anaesthesia ascertainment. Limiting analysis to caesarean sections resulted in very accurate identification of general anaesthesia for delivery (sensitivity 97.0%, specificity 99.8%) while limiting to vaginal births was moderately accurate for identifying postpartum general anaesthesia (sensitivity 73.2%, specificity 99.8%). General anaesthesia for delivery is reported with a high level of accuracy in birth and linked birth-hospital data, but not in hospital discharge data alone. Population health data are a reliable source for examining general anaesthesia for delivery.