Accuracy of congenital anomaly coding in live birth children recorded in European health care databases, a EUROlinkCAT study.

Electronic health care databases are increasingly being used to investigate the epidemiology of congenital anomalies (CAs) although there are concerns about their accuracy. The EUROlinkCAT project linked data from eleven EUROCAT registries to electronic hospital databases. The coding of CAs in electronic hospital databases was compared to the (gold standard) codes in the EUROCAT registries. For birth years 2010-2014 all linked live birth CA cases and all children identified in the hospital databases with a CA code were analysed. Registries calculated sensitivity and Positive Predictive Value (PPV) for 17 selected CAs. Pooled estimates for sensitivity and PPV were then calculated for each anomaly using random effects meta-analyses. Most registries linked more than 85% of their cases to hospital data. Gastroschisis, cleft lip with or without cleft palate and Down syndrome were recorded in hospital databases with high accuracy (sensitivity and PPV ≥ 85%). Hypoplastic left heart syndrome, spina bifida, Hirschsprung's disease, omphalocele and cleft palate showed high sensitivity (≥ 85%), but low or heterogeneous PPV, indicating that hospital data was complete but may contain false positives. The remaining anomaly subgroups in our study, showed low or heterogeneous sensitivity and PPV, indicating that the information in the hospital database was incomplete and of variable validity. Electronic health care databases cannot replace CA registries, although they can be used as an additional ascertainment source for CA registries. CA registries are still the most appropriate data source to study the epidemiology of CAs.

The quality and the accuracy of codes for terminations of pregnancy for fetal anomalies recorded in hospital databases in three countries in northern Europe.

BACKGROUND: The number of terminations of pregnancy for fetal anomalies in Europe (TOPFA) has increased over recent decades. Therefore, it is important that TOPFAs, in addition to all other birth outcomes, are included in the surveillance of congenital anomalies and in studies on possible teratogenic risks of pregnancy exposures. The aim of this study was to evaluate the quality and the accuracy of codes identifying TOPFA cases in hospital databases. METHODS: TOPFA cases recorded in three EUROCAT congenital anomaly registries (Finland, 2010-2014; Funen in Denmark, 2005-2014; and northern Netherlands, 2013-2014) were linked to hospital databases using maternal IDs. RESULTS: A total of 2,114 TOPFA cases over the study period were identified in the registries and 2,096 (99%) of these pregnancies were identified in the hospital databases. An end of pregnancy code was present for 91% of the cases and a code for a congenital anomaly was present for 82% (with some differences across registries). The proportion of TOPFA cases with a code for a specific congenital anomaly was <50% for cases with a structural anomaly (range 0%-50%) and 70% for cases with a chromosomal anomaly. CONCLUSION: Hospital databases have limited information or codes to identify TOPFAs for specific anomalies and the data are not detailed enough for surveillance of congenital anomalies or for studies analyzing pregnancy exposures and risk of congenital anomalies. However, hospital data may be used to identify the occurrence of a TOPFA to enable more detailed information to be obtained from the medical records.