Prevalence Of Rheumatoid Arthritis In Germany: Analysis Of Longitudinal Data Of Statutory Health Insurance

Background Rheumatoid arthritis (RA) is a progressive chronic inflammatory systemic autoimmune disease with destructive joint changes. Data on prevalence in adult patients are only available to a limited extent in Germany.Methodology Anonymised diagnosis and prescription data for 2008-2013 were evaluated at patient level for approximately 2.3 million insured adults (total data set; status 2013) and approx. 1.2 million insured adults (smaller data set with additional information such as treatment by a specialist; status 2013) from 7 different statutory health insurance companies. RA was diagnosed if the code M05 (seropositive chronic polyarthritis) or M06 (other chronic polyarthritis) was present (diagnosis group M0[5,6]) and if the patient was either an outpatient at least twice (in 2 different quarters) or at least once an inpatient within a calendar year (according to the BVA criteria, inpatient diagnoses were thus classified as more reliable). The data were extrapolated to the SHI-insured and total population in Germany for 2013.Results The prevalence of RA in the total data set was 1.26 % on average over all years (2008-2013). More than 90 % of the diagnosis was based on the diagnosis code M06. In 88 % of the cases, the classification was based exclusively on outpatient diagnoses. Taking into account a diagnosis by a specialist based on a smaller data set containing this additional information to determine a "reliable" RA diagnosis, the average RA rate for 2011-2013 was about 0.99 %. Related to the diagnosis group M0[5,6] in the total data set, the prevalence of RA in 2013 was about 1.8 % of women and about 0.8 % of men. Only about 40 % of diagnosed patients were treated with DMARDs.Conclusions The prevalence estimates for RA derived from the larger data set correspond to those of previous surveys with partially different methodological approaches. Based on the analysis of the health insurance data presented, the prevalence of diagnosed RA in adults in Germany is 1.26 %, which is within the range of 0.81-1.62 % that can be found in the literature. This represents about 721,000 adult SHI-insured persons. The low rate of DMARD prescriptions may indicate inadequate care of these patients.