Validation of the Thai version of the questionnaire for identifying subjects with potential rheumatic diseases

Objective: To translate and evaluate the diagnostic property and the feasibility of the Thai version of the questionnaire for identifying subjects with potential rheumatic diseases. Material and Method: The original screening questionnaires by Liang MH et al were translated and modified from the English version to the Thai version. The Thai version of the questionnaire was administered to 450 subjects. Results: Two hundred and twenty-five patients who fulfilled standard diagnostic criteria of each rheumatic disease and 225 healthy subjects were consecutively recruited. A positive response to one or more questions of the questionnaire gave a sensitivity (95% confidence interval or CI), specificity (95% CI), positive, and negative likelihood ratios of 94% (90-97), 73% (67-79), 3.48, and 0.08, respectively. The accuracy of test was 93%. Median time-to-complete questionnaire was three minutes (range 0.5-15). Most of them (95%) completed questionnaires by themselves. However, 12% of the questionnaires had missing items. False positive was prevalent in women, young age, high-educated individuals, and government officers. Conclusion: The Thai version of the screening questionnaire is valid and easy to use for identifying subjects with potential rheumatic diseases. It is suitable to use as a screening tool in primary care setting or epidemiologic research.