BC | NDB | GPRD | NOAR | Sweden ERA | |
Country | Canada | USA | UK | UK | Sweden |
Data type | Administrative data on physician visits, hospitalisations and medications | Patient questionnaire | Electronic medical records | Patient questionnaire and assessment | Electronic medical records, patient assessment |
Time period | 1996–2001 | 1998–2003 | 1987–2001 | 1990–9 | 1994–2003 |
No of RA patients in cohort | 27 710 | 21 229 | 38 622 | 839 | 3703 |
Type of cohort | Population-based, prevalent cases | Longitudinal cohort, prevalent cases referred by rheumatologists | Population-based, prevalent cases | Early RA cohort | Early RA cohort |
No of DMARD-treated RA patients | 12 337 | 10 499 | 14 467 | 523 | 3703 |
DMARD users | Prevalent users | Prevalent users | Prevalent users | Incident users | Incident users |
Case ascertainment | ICD-9 codes on claims and discharge summaries | Patient-reported and verified by medical and hospital records | OXMIS codes; codes validated by an oncologist | ICD-9 codes in linked medical records | ICD-10 codes and verified by linking to cancer registry |
BC, British Columbia RA Cohort; DMARD, disease-modifying antirheumatic drug; GPRD, General Practice Research Database; ICD, International Classification of Diseases; NDB, National Data Bank for Rheumatic Diseases; NOAR, Norfolk Arthritis Register; RA, rheumatoid arthritis; Sweden ERA, Sweden Early Rheumatoid Arthritis Register.