Reexamination of the assessment criteria for rheumatoid arthritis disease activity based on comparison of the Disease Activity Score 28 with other simpler assessment methods.

OBJECTIVE: To explore simpler and possibly more appropriate tools than the conventional Disease Activity Score 28 (DAS28) for assessing rheumatoid arthritis (RA) and to derive more reliable DAS28-based criteria.
METHODS: The capabilities of assessing disease activities in 250 RA patients were compared between DAS28 and other methods, including the Simplified DA Index (SDAI), Clinical DA Index (CDAI), and Routine Assessment of Patient Index Data-3 (RAPID-3).
RESULTS: SDAI and CDAI showed a good correlation and consistency with DAS28, whereas RAPID-3 yielded inferior results. In terms of remission criteria, DAS28 was less stringent than SDAI or CDAI; when RA remission was reexamined based on more stringent SDAI or CDAI criteria, cut-off values for DAS28-C-reactive protein of <1.72 were considered to be appropriate. The conventional DAS28 was considered to be appropriate for assessing low, middle and high disease activities because it provides criteria similar to or more stringent than those of other methods, while SDAI and CDAI were considered to be simpler and more appropriate criteria for assessing remission.
CONCLUSION: For assessing remission, DAS28-CRP provides the most appropriate criterion of the methods compared when the currently used cut-off value of 2.3 is lowered to a new value of 1.72.