Data quality and patient characteristics in European ANCA-associated vasculitis registries: data retrieval by federated querying

Abstract

Objectives: This study aims to describe the data structure and harmonisation process, explore data quality and define characteristics, treatment, and outcomes of patients across six federated antineutrophil cytoplasmic antibody-associated vasculitis (AAV) registries.

Methods: Through creation of the vasculitis-specific Findable, Accessible, Interoperable, Reusable, VASCulitis ontology, we harmonised the registries and enabled semantic interoperability. We assessed data quality across the domains of uniqueness, consistency, completeness and correctness. Aggregated data were retrieved using the semantic query language SPARQL Protocol and Resource Description Framework Query Language (SPARQL) and outcome rates were assessed through random effects meta-analysis.

Results: A total of 5282 cases of AAV were identified. Uniqueness and data-type consistency were 100% across all assessed variables. Completeness and correctness varied from 49%-100% to 60%-100%, respectively. There were 2754 (52.1%) cases classified as granulomatosis with polyangiitis (GPA), 1580 (29.9%) as microscopic polyangiitis and 937 (17.7%) as eosinophilic GPA. The pattern of organ involvement included: lung in 3281 (65.1%), ear-nose-throat in 2860 (56.7%) and kidney in 2534 (50.2%). Intravenous cyclophosphamide was used as remission induction therapy in 982 (50.7%), rituximab in 505 (17.7%) and pulsed intravenous glucocorticoid use was highly variable (11%-91%). Overall mortality and incidence rates of end-stage kidney disease were 28.8 (95% CI 19.7 to 42.2) and 24.8 (95% CI 19.7 to 31.1) per 1000 patient-years, respectively.

Conclusions: In the largest reported AAV cohort-study, we federated patient registries using semantic web technologies and highlighted concerns about data quality. The comparison of patient characteristics, treatment and outcomes was hampered by heterogeneous recruitment settings.

Keywords: epidemiology; granulomatosis with polyangiitis; quality indicators, health care; systemic vasculitis.

Figure 1

FAIRVASC project workflow. Registry data are quality controlled and harmonised to a common schema. Harmonised data are uploaded to a local server with an exposed endpoint. A researcher dispatches a predefined query from a web interface to the local servers. Statistical calculations are performed locally, and non-subject level results sent back. Data are combined and presented to the web-interface user. FAIRVASC, Findable, Accessible, Interoperable, Reusable, VASCulitis.

Figure 2

Data quality metrics per registry as percentages per key registry variables. (A) Data uniqueness (the absence of duplication of data) and data-type consistency. (B) Plausibility of data values and data completeness (the absence of missing data). (C) Data completeness (the absence of missing data) and correctness (assessed against available electronic health records). Variables that were missing from a registry because they were not targeted for collection are shown as the absence of a bar. Full data available in online supplemental table 4. ANCA, antineutrophil cytoplasmic antibody; BVAS, Birmingham Vasculitis Activity Score; CRP, C reactive protein; ESKD, end-stage kidney disease; FVSG, French Vasculitis Study Group; GeVas, Joint Vasculitis Registry in German-speaking Countries; POLVAS, Polish Vasculitis Registry; RKD, Rare Kidney Disease.

Figure 3

All-cause mortality rate per 1000 patient years. Forest plot showing estimated all-cause mortality rate per 1000 patient years. Per registry and pooled estimates shown with 95% CI. FVSG, French Vasculitis Study Group; GeVas, Joint Vasculitis Registry in German-speaking Countries; POLVAS, Polish Vasculitis Registry; RKD, Rare Kidney Disease.

Figure 4

Incidence rate of end-stage kidney disease per 1000 patient years per registry. Forest plot showing estimated incidence rate of end-stage kidney disease per 1000 patient years. Per registry and pooled estimates shown with 95% CI. FVSG, French Vasculitis Study Group; GeVas, Joint Vasculitis Registry in German-speaking Countries; POLVAS, Polish Vasculitis Registry; RKD, Rare Kidney Disease.