[A comparison between the Simplified Disease Activity Index (SDAI) and the Disease Activity Score (DAS28) as measure of response to treatment in patients undergoing different therapeutic regimens].

OBJECTIVE To compare the SDAI values to DAS28 scores in RA patients undergoing different DMARD regimens. METHODS The SDAI is an unweighted numerical sum of five outcome parameters: tender and swollen joint count (based on 28-joint assessment), patient and physician global assessment of disease activity (visual analogue scale: 0-10 cm) and level of C-reactive protein (mg/dl). 80 patients (F/M 68/12; age between 20-68 years, median 52) with active rheumatoid arthritis were prospectively enrolled in the study. The patients were randomly assigned to one of four groups according to the therapeutic regimens: group I: Methotrexate (MTX) 15 mg/weekly + salazopyrin 2 g/daily; group II: MTX 15 mg/weekly + infliximab 3 mg/Kg at time 0, 2, 4 and every 8 weeks; group III: MTX 15 mg/weekly + etanercept 25 mg/twice weekly; group IV: MTX 15 mg/weekly + adalimumab 40 mg/every other week. SDAI and DAS28 were determined at baseline and after 6 months in each patient. Mean changes in SDAI values were compared to those detected in DAS 28 at baseline and after 6 months. RESULTS SDAI and DAS 28 were found to be significantly correlated at baseline. Moreover, changes in SDAI over time paralleled those in DAS, and were found to be significantly correlated. CONCLUSIONS SDAI is a valid measure of response to treatment in RA patients undergoing different therapeutic regimens.