Cross-national health care database utilization between Spain and France: results from the EPICHRONIC study assessing the prevalence of type 2 diabetes mellitus

Abstract

Guillaume Moulis,1–3,* Berta Ibañez,4–6,* Aurore Palmaro,2,3 Felipe Aizpuru,6–8 Eduardo Millan,6,8 Maryse Lapeyre-Mestre,2,3,9 Laurent Sailler,1–3 Koldo Cambra5,6,10 1Department of Internal Medicine, Toulouse University Hospital, Toulouse, France; 2UMR1027 INSERM, University of Toulouse, Toulouse, France; 3Clinical Investigation Center 1436, Toulouse University Hospital, Toulouse, France; 4Navarrabiomed, Health Department, Public University of Navarra, Pamplona, Spain; 5IdiSNA, Pamplona, Spain; 6Health Service Research on Chronic Patients Network (REDISSEC), Pamplona, Spain; 7Research Unit Araba (BioAraba), Osakidetza-Basque Health Department, Vitoria-Gasteiz, Spain; 8Healthcare Services Sub-directorate, Osakidetza-Basque Health Service, Araba, Spain; 9Department of Medical and Clinical Pharmacology, Toulouse University Hospital, Toulouse, France; 10Institute of Public Health and Labour Health of Navarra, Pamplona, Spain *These authors contributed equally to this work Aim: The EPICHRONIC (EPIdemiology of CHRONIC diseases) project investigated the possibility of developing common procedures for French and Spanish electronic health care databases to enable large-scale pharmacoepidemiological studies on chronic diseases. A feasibility study assessed the prevalence of type 2 diabetes mellitus (T2DM) in Navarre and the Basque Country (Spain) and the Midi-Pyrénées region (France). Patients and methods: We described and compared database structures and the availability of hospital, outpatient, and drug-dispensing data from 5.9 million inhabitants. Due to differences in database structures and recorded data, we could not develop a common procedure to estimate T2DM prevalence, but identified an algorithm specific to each database. Patients were identified using primary care diagnosis codes previously validated in Spanish databases and a combination of primary care diagnosis codes, hospital diagnosis codes, and data on exposure to oral antidiabetic drugs from the French database. Results: Spanish and French databases (the latter termed Système National d’Information Inter-Régimes de l’Assurance Maladie [SNIIRAM]) included demographic, primary care diagnoses, hospital diagnoses, and outpatient drug-dispensing data. Diagnoses were encoded using the International Classification of Primary Care (version 2) and the International Classification of Diseases, version 9 and version 10 (ICD-9 and ICD-10) in the Spanish databases, whereas the SNIIRAM contained ICD-10 codes. All data were anonymized before transferring to researchers. T2DM prevalence in the population over 20 years was estimated to be 6.6–7.0% in the Spanish regions and 6.3% in the Midi-Pyrénées region with ~2% higher estimates for males in the three regions. Conclusion: Tailored procedures can be designed to estimate the prevalence of T2DM in population-based studies from Spanish and French electronic health care records. Keywords: epidemiology, pharmacoepidemiology, electronic health care database, cross-national study, population-based study, type 2 diabetes mellitu