Rheumatoid Arthritis

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory syndrome that causes pain, swelling and, if untreated, progressive damage to joints. The UK prevalence of RA has been estimated as 0.8%1 which equates to ∼690 000 people. In addition to disability and poorer quality of life, RA is also associated with increased morbidity and mortality compared with the general population.2 The leading cause of death among RA patients is cardiovascular disease, with risk 50% higher than the general population.3

UK Biobank is a very large general population cohort study of middle-to-older-aged adults in the UK designed to be representative of the general population in terms of age, sex, socioeconomic status and ethnicity. It was created to provide a useful resource to study a wide range of important chronic conditions of adulthood, such as RA. Follow-up is being conducted via linkage to routine administrative data sources such as primary care attendances, hospital admissions, drug prescriptions and death certificates and will, in due course, provide information on incident cases of RA. Genetic, biomarker and imaging data will also become available in future which will greatly enhance the studies that can be undertaken using the UK Biobank cohort. However, because of the age criteria used, large numbers of participants already have prevalent diseases such as RA at recruitment, permitting cross-sectional studies to be undertaken now. It is vital to determine the baseline characteristics of the participants with a specific condition such as RA before subsequent studies can be undertaken and their relevance and significance deduced. The aim of this study was to ascertain the frequency and distribution of reported RA within this very large general population cohort study, and the extent to which it was associated with comorbid conditions. Our work provides a comprehensive baseline evaluation on which many subsequent analyses on this uniquely phenotyped and genotyped cohort (for around n=150 000 and the rest due in Q3 2016) can be performed.