Data accuracy in the Victorian Perinatal Data Collection: Results of a validation study of 2011 data

Objective: Public health data sets such as the Victorian Perinatal Data Collection (VPDC) provide an important source for health planning, monitoring, policy, research and reporting purposes. Data quality is paramount, requiring periodic assessment of data accuracy. This article describes the conduct and findings of a validation study of data on births in 2011 extracted from the VPDC. Method: Data from a random sample of one percent of births in Victoria in 2011 were extracted from original medical records at the birth hospital and compared with data held in the VPDC. Accuracy was determined for 93 variables. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for dichotomous items. Results: Accuracy of 17 data items was 99% or more, the majority being neonatal and intrapartum items, and 95% or more for 46 items. Episodes of care with the highest proportion of items with accuracy of 95% or more were neonatal and postnatal items at 80 and 64%, respectively. Accuracy was below 80% for nine items introduced in 2009. Agreement between medical records and VPDC data ranged from 48% to 100%, the exception being two highly inaccurate smoking-related items. Reasons for discrepancies between VPDC data and medical records included miscoding, missing and inconsistent information. Conclusion: This study found high levels of accuracy for data reported to the VPDC for births in 2011; however, some data items introduced in 2009 and not previously validated were less accurate. Data may be used with confidence overall and with awareness of limitations for some new items.