Disease Activity States for ASDAS Score

Four disease activity states for the ASDAS score have been defined: The ASDAS assessment measures four disease activity states: inactive, moderate, high, and very high. Disease status was evaluated on the basis of three cutoff values: 1.3, 2.1, and 3.5 units. The 3 cut-offs selected to separate these states were: < 1.3 between "inactive disease" and "moderate disease activity", < 2.1 between "moderate disease activity" and "high disease activity", and > 3.5 between "high disease activity" and "very high disease activity". The following cutoff values were selected to indicate improvement: a change of ≥ 1.1 units denoted a clinically important improvement, and a change of ≥ 2.0 units denoted a major improvement^{15 (link)–18 (link)}.