Prevalence survey of rheumatoid arthritis and spondyloarthropathy in Lithuania

To assess the prevalence of rheumatoid arthritis (RA) and spondyloarthropathy (SpA) in two Lithuanian cities, Vilnius and Kaunas.

The first step in this study involved the translation and validation of a telephone questionnaire developed by rheumatologists and epidemiologists in France. The second step comprised the prevalence survey. To detect RA and SpA cases in the populations of Vilnius and Kaunas, 6542 subjects selected randomly (every 50th) from the latest telephone book were interviewed by telephone using a validated case detection questionnaire (the screening phase). All subjects with rheumatic symptoms but an uncertain diagnosis were contacted by a rheumatologist (confirmation phase) by telephone. If the diagnosis remained uncertain, the subjects were invited for a rheumatological examination.

We attempted to contact 3370 telephone numbers in Vilnius and 3172 in Kaunas, and had a response rate of 62.5% and 67.7%, respectively. Over the course of all the study phases (telephone interview, rheumatologist's interview, and clinical examination), 39 RA cases and 27 SpA cases were detected, resulting in a crude prevalence of 0.92% for RA (95% CI 0.65-1.25) and 0.64% (95% CI 0.42-0.92) for SpA. The standardized prevalence rate according to age and sex in the Lithuanian population showed an RA prevalence of 0.55 (95% CI 0.39-0.74) and a SpA prevalence of 0.84 (95% CI 0.53-1.21).

The prevalence of RA and SpA in Lithuania was found to be one of the higher rates in Europe. A telephone interview using a validated short questionnaire enabled a cost- and time-saving epidemiological survey to be conducted to detect RA and SpA cases in the community.