Abstract

Aims: Registries have the potential to capture treatment practices and outcomes in populations beyond the constraints of clinical trial settings. The value of data obtained depend critically upon robust quality standards (including source data verification [SDV] and training); features that are commonly absent from registries. This article outlines the quality standards developed for Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF). Methods and Results: GARFIELD-AF comprises ∼57 000 patients prospectively recruited over 6.5 years in 35 countries in five successive cohorts. The registry employs a combination of remote and onsite monitoring to ascertain completeness and accuracy of records and by design, SDV is performed on 20% of cases (i.e. ∼11 400 patients). Four performance measures for ranking sites according to data quality and other performance indicators were evaluated (including data quality for 13 quantifiable variables, late data locking, number of missing critical variables, and history of poor data quality from the previous monitoring phase). These criteria facilitated the identification of sites with potentially suboptimal data quality for onsite monitoring. During early phases of the registry, critical variables for data checking were also identified. SDV using these variables (partial SDV in 902 patients) showed similar concordance to SDV of all fields (110 patients): 94.4% vs. 93.1%, respectively. This standard formed the baseline against which ongoing quality improvements were assessed, facilitating corrective action on data quality issues. In consequence, concordance was improved in the next monitoring phase (95.6%; n = 1172). Conclusion: The quality standards in GARFIELD-AF have the potential to inform a future 'reference' for registries.