ANZARD Data Linkage – Agreement Between Births Recorded by Clinics and in NSW Perinatal Data Collection

Abstract

Background: Fertility clinics submit treatment data on all ART cycles to the Australian and New Zealand Assisted Reproductive Technology Database (ANZARD) as part of their accreditation. The National Perinatal Epidemiology and Statistics Unit (NPESU), who manages ANZARD, is undertaking a study involving the linkage of ANZARD to state and commonwealth datasets to investigate health outcomes of infants born from fertility treatments. Aim: To describe the creation and performance of the linked dataset and to evaluate the agreement between births recorded by clinics and those recorded in state perinatal data collections (PDC). Method: The linked dataset was created by linking the ANZARD to NSW and ACT administrative datasets (performed by NSW Centre for Health Record Linkage (CHeReL)) and to Medicare Benefits Scheme and Pharmaceutical Benefits Schedule (performed by AIHW). The CHeReL’s Master Linkage Key (MLK) was used as a bridge between ANZARD’s statistical linkage key and state administrative datasets. Linkage rates and concordance between births recorded in ANZARD and PDCs was evaluated. Results: A 96.7% linkage rate was achieved between women recorded in ANZARD and CHeReL’s MLKs. A reconciliation of ANZARD-recorded births among NSW residents found that 94.2% (95% CI: 93.9-94.4%) of births were also recorded in NSW/ACT PDCs. A proportion of the missing births could be to women who had ART treatment in NSW but birthed in a different Australian state or country. A high concordance rate (>99%) was found in plurality status and birth outcome between ANZARD and PDCs. Conclusion: High linkage rates can be achieved with partially identifiable data and population spines, such as the CHeReL’s MLK, can be successfully used to link clinical registries and administrative datasets. This linkage resource will provide invaluable information on the safety of the ART and non-ART treatment, and the role of subfertility on the fertility treatments for Australia and beyond.