Adaptation and validation of a telephone questionnaire - : Serbian version for case detection of rheumatoid arthritis and spondyloarthropathy (multicentric Eular study)

To adapt and validate a telephone questionnaire for case detection of rheumatoid arthritis (RA) and spondyloarthropathies (SpA) in the Serbian population. A questionnaire, developed by the French Society of Rheumatology and successfully tested in France, was adapted to the Serbian language using a cross-cultural adaptation process. It was validated in 150 patients: 50 with RA, 50 with SpA and 50 with degenerative rheumatic disorders. They were recruited from Institute of Rheumatology in Belgrade, hospital registry, years 2001 and 2002. The questionnaire validity was assessed in reference to clinical diagnosis and ACR 1987 and ESSG 1991 classification criteria. A logistic regression model was used for RA-control and SpA-control comparison to identify the set of items that best discriminates these groups. Cross-cultural adaptation of the Questionnaire was successfully achieved, verifying its equivalence with the original (semantic, idiomatic, experiential, conceptual). According to the logistic regression, two items selected for RA provided 92.1% agreement when using either clinical diagnosis or ACR classification criteria as a standard. SpA-control comparison included five items providing 96.8% agreement with clinical diagnosis and four items providing 94.1% agreement with ESSG criteria. Results of the present study are similar to those found in the French study. Validation results of the telephone questionnaire, translated and adapted to the Serbian language, confirm that it can be used as a detection tool for RA and SpA cases in the population of Serbia, whose diagnoses would have to be further confirmed.