Prevalence of rheumatic diseases in Russia

Aim: To estimate the prevalence of the rheumatic diseases in an epidemiological study.

Materials and methods: During a  questionnaire survey among 76 162 adult individuals in 12 regions of the Russian Federation, those with complaints of joint pain and swelling were selected and a group (n = 4894) was formed at random for subsequent clinical assessment by rheumatologists to identify main rheumatic diseases. In all regions, the study was conducted according to the unified protocol, with the unified strategy of the population selection and the use of unified questionnaires. Diagnoses were made based on widely adopted classification criteria for rheumatic diseases.

Results: For the first time in Russia it was found that among adult Russian population, the life-time prevalence of joint pain (mostly knee and hip) was 39.5%, whereas that of joint swelling amounted to 26%. From those, arthralgias eventually disappear in 8% and arthritis, in 7%. Among all rheumatic clinical entities, knee and/or hip osteoarthritis ranks the first, with its prevalence calculated to all adult population of Russia above 18 years of age being 13%. The prevalence of rheumatoid arthritis was 0.61%, of ankylosing spondylitis, 0.1%, psoriatic arthritis, 0.37%, reactive arthritis, 0.42%, gout, 0.3%, and of systemic connective tissue disorders (systemic lupus erythematosus, systemic sclerosis, dermatomyositis/polymyositis, Sjogren's syndrome, systemic vasculitis, etc),  0.11%.

Conclusion: The true prevalence of the rheumatic diseases found in the epidemiological study was higher than the data of the official statistics as follows: 2.5-fold for rheumatoid arthritis, 5-fold for osteoarthritis, 3.5-fold for spondyloarthritis and 3-fold for systemic connective tissue disorders. The results obtained showed an underestimation of the rheumatic diseases and incomplete data in the country statistics. This might be related to low referral levels for medical care due to significant distances of the vast regional areas from the specialized centers, as well as with insufficient qualification of primary care physicians in the field of rheumatology. All together, this leads to inevitable and serious misdiagnoses and low registration of the rheumatic diseases.