Infection rates in patients from five rheumatoid arthritis (RA) registries: contextualising an RA clinical trial programme

Abstract

ObjectivePatients with rheumatoid arthritis (RA) have an increased risk of serious infections. Comparing infection rates across RA populations is complicated by differences in background infection risk, population composition and study methodology. We measured infection rates from five RA registries globally, with the aim to contextualise infection rates from an RA clinical trials population.MethodsWe used data from Consortium of Rheumatology Research of North America (CORRONA) (USA), Swedish Rheumatology Quality of Care Register (Sweden), Norfolk Arthritis Register (UK), CORRONA International (multiple countries) and Institute of Rheumatology Rheumatoid Arthritis (Japan) and an RA clinical trial programme (fostamatinib). Within each registry, we analysed a main cohort of all patients with RA from January 2000 to last available data. Infection definitions were harmonised across registries. Sensitivity analyses to address potential confounding explored subcohorts defined by disease activity, treatment change and/or prior comorbidities and restriction by calendar time or follow-up. Rates of infections were estimated and standardised to the trial population for age/sex and, in one sensitivity analysis also, for Health Assessment Questionnaire (HAQ) score.ResultsOverall, age/sex-standardised rates of hospitalised infection were quite consistent across registries (range 1.14–1.62 per 100 patient-years). Higher and more consistent rates across registries and with the trial programme overall were seen when adding standardisation for HAQ score (registry range 1.86–2.18, trials rate 2.92) or restricting to a treatment initiation subcohort followed for 18 months (registry range 0.99–2.84, trials rate 2.74).ConclusionThis prospective, coordinated analysis of RA registries provided incidence rate estimates for infection events to contextualise infection rates from an RA clinical trial programme and demonstrated relative comparability of hospitalised infection rates across registries.

A large observational cohort study of rheumatoid arthritis, IORRA: Providing context for today’s treatment options

“…No significant differences were found in the outcomes of these cohorts after adjusting for age and sex. The results provide a meaningful rationale for conducting a world-wide epidemiological study of RA [19].…”

Treatment patterns and achievement of the treat-to-target goals in a real-life rheumatoid arthritis patient cohort: data from 1317 patients

“…This rate is somewhat lower from what has been recently reported from other RA registries worldwide (range: 58-76%). 19 For example, in the US CORRONA registry among 24,176 RA patients (with 38% bDMARD use), 58% of patients had still active disease (DAS28ESR ⩾3.2). 20 One year later, a small but statistically significant increase in the proportion of patients who achieved LDA was noted (57%; +5%).…”

Opportunities and challenges for real-world studies on chronic inflammatory joint diseases through data enrichment and collaboration between national registers: the Nordic example

“…By contrast, separate but harmonised analyses (option 3) put particular demands on harmonisation not only of the raw data but also of the statistical analysis plan to be executed at each register. Since the absence of pooling of individual-level data precludes the potential for adjusted analyses across data sets, other means to accommodate important risk determinants across data sets must be implemented (eg, stratification and standardisation, as exemplified in a recently published study 26 ). The analytical ‘output’ to be pooled through meta-analytic approaches may vary from rates to actual relative risk estimates.…”