Background The PROMs-Arthritis questionnaire [1] was developed to evaluate the patient reported outcomes in individuals with inflammatory arthritis. Translation of the questionnaire to other languages will provide a standard outcome measure across populations.

Objectives To translate the English version of the Patient Reported Outcome Measures for inflammatory arthritis (PROMs-Arthritis) to Bulgarian; and evaluate the psychometric properties of the Bulgarian version.

Methods The PROMs-Arthritis questionnaire was cross-culturally adapted to Bulgarian, according to established guidelines. The validity and reliability of the Bulgarian version were assessed in 110 patients with rheumatoid arthritis (RA) as well as 44 healthy control. The questionnaire includes assessment for functional disability, quality of life, VAS for joint pain, patient global status, fatigue, duration of morning stiffness, assessment of co-morbidities, patient activation as well as self-reported joint pain.

Results The expert committee and the participants considered the questionnaire to have good face and content validity. Dimensionality analysis revealed a 1-factor solution, explaining 97% of the total variance. Known group validity was demonstrated by significant differences between patients compared with the asymptomatic group (P<0.001). An item analysis showed a high degree of internal consistency (Cronbach α=0.805).The Bulgarian version exhibited excellent test-retest reliability (intraclass correlation coefficient =0.805 for the arthritis group). The questionnaire items correlated significantly (p<0.01) with clinical parameters of disease activity (DAS-28), physician global assessment, ESR and CRP levels. RA patient self-reported tender joints correlated significantly with the physicians' scores (0.893). Changes in functional disability, quality of life as well as Patient Activation scores showed significant (p<0.01) variation, with diseases activity status (DAS-28). The questionnaire showed also a high degree of comprehensibility (9.4).

Conclusions Integrating patient reported outcome measures into standard clinical practice is feasible and applicable. The Bulgarian version, adapted from the original English PROMs-Arthritis questionnaire, shows a considerable validity and reliability, and its psychometric properties are comparable with the original version.

1. El Miedany Y et al. Clin Exp Rheumatol. 2010 Sep-Oct;28(5):734–44.

Disclosure of Interest None declared