Importance of Disease Activity Indices in Indian Rheumatoid Arthritis (RA) Patients of Western Region

Abstract

Objectives: Our objective was to evaluate the level of similarity between SDAI, CDAI, DAS28-ESR and DAS28-CRP in our study population which will help in the quick assessment of the disease for immediate treatment modalities. Methods:The study population consisted of 38 Rheumatoid Arthritis (RA) patients attending the OPD of our hospital. After a detailed medical history and anthropometric evaluation, all the participants were subjected to biochemical analysis like CRP, ESR and their disease activity scores were calculated using DAS calculator. SDAI and CDAI were also calculated. The correlations between the four indices were studied through the Pearson's correlation coefficient (r) and the similarity between these indices was evaluated through Kendall's (K) "tau" similarity coefficient. Results:The 38 RA patients were of mean age of 42.08 ± 12.92 years with the disease duration of mean of 36 months (1 month-20 years). The DAS28-ESR mean score was 5.56 ± 0.90. The DAS28-CRP mean score was 4.93 ± 0.86. The CDAI mean score was 26.45 ± 8.42 and that of SDAI was 28.20 ± 9.08. A positive, statistically significant correlation was noted between the four indices for RA activity. The level of similarity between these indices was good (K variation between 0.699 and 0.910). 42.1% of the patients were classified as 'high' disease activity level, when DAS28-ESR and DAS28-CRP scores were considered together. This proportion was of 42.1%, when comparing DAS28-CRP respectively to CDAI and SDAI, compared to 60.5% when DAS28-ESR and SDAI were considered whereas DAS28-ESR and CDAI classified 65.8% of the patients as 'high' disease activity. Finally, CDAI and SDAI classified the patients upto 60.5% as having a 'high' disease activity level. Conclusion:DAS28-CRP, DAS28-ESR, CDAI and SDAI correlated well for assessing the disease activity status for the RA patients. CDAI and especially SDAI have a good level of similarity with DAS28.