Construct and criterion validity of several proposed DAS28-based rheumatoid arthritis flare criteria: An OMERACT cohort validation study

摘要

Background To describe rheumatoid arthritis (RA) worsening that leads to change or re-initiation of treatment, several Disease Activity Score 28 (DAS28)- based flare criteria have been described, but none validated. Methods Six previously published DAS28-based flare criteria ((1) increase in DAS28 1.2, or 0.6 if DAS28 5.1; (2) increase in DAS28 1.2, or 0.6 if DAS28 ≥3.2; (3) increase 0.6 or DAS28 3.2; (4) increase in DAS28 1.2; (5) DAS28 3.2; (6) DAS28 2.6) were tested against five hypotheses concerning criterion and construct validity: (1+2) Sensitivity and specificity 70% compared with patient's/physician's judgment; (3) difference in proportion with disease modifying antirheumatic drug/corticosteroid initiation/increase 0.2; (4) mean difference in C-reactive protein (CRP) 10 mg/l; and (5) no statistical difference in Short Form-36 Mental Health subscale change. Three different RA patient databases in which flare might occur were used. Sensitivity/specificity, χ2 and two-sample student t test analyses were done. Results The analyses included 51, 147 and 744 RA patients, from the three databases. Criterion 2 fulfilled most hypotheses: 4 out of 5. Sensitivity and specificity varied between 63%.78% and 84%.92%. Construct validity was demonstrated with 23% more treatment change, higher mean CRP (11.4 mg/l) and depression scale change of .5. Criteria 3, 5 and 6 were more sensitive, criteria 1, 2 and 4 more specific. Conclusions An increase in DAS28 1.2 or 0.6 if DAS28 ≥3.2 appears most discriminating and valid by our predefined validation criteria. Considering the other criteria, sensitivity and specificity shown here might facilitate use in different settings.