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Table 3 Elaboration and evaluation of the external validity of the different potential thresholds defining an acceptable status in the rheumatoid arthritis impact of disease (RAID) score

From: Defining cut-off values for disease activity states and improvement scores for patient-reported outcomes: the example of the Rheumatoid Arthritis Impact of Disease (RAID)

ELABORATION Time of evaluation during the studyc EVALUATION
Proposed thresholda    Patient's perspectived Physician's perspectivee
    Se Spe LR+ (95% CI) Se Spe LR+ (95% CI)
a. ≤ 1 Empirical Week 4 21.2 94.3 3.7 (0.9; 15.4) 32.1 93.0 4.6 (1.7; 12.4)
a. ≤ 1 Empirical Week 12 25.3 100.0 ND 31.1 90.2 3.2 (1.2; 8.1)
b. ≤ 2 Empirical Week 4 36.4 91.4 4.2 (1.4; 13.1) 50.0 84.5 3.2 (1.7; 6.2)
b. ≤ 2 Empirical Week 12 50.6 95.0 10.1 (1.5; 69.3) 66.7 80.4 3.4 (1.9; 6.2)
c. ≤ 3 Empirical Week 4 54.5 82.9 3.2 (1.5; 6.8) 82.1 76.1 3.4 (2.2; 5.4)
c. ≤ 3 Empirical Week 12 69.6 80.0 3.5 (1.4; 8.5) 80.0 56.9 1.9 (1.3; 2.6)
d. ≤ 3.3 75th percentile at week 12 Week 4 63.6 77.1 2.8 (1.5; 5.3) 89.3 67.6 2.8 (1.9; 3.9)
d. ≤ 3.3 75th percentile at week 12 Week 12 77.2 80.0 3.9 (1.6; 9.4) 82.2 47.1 1.6 (1.2; 2.1]
e. ≤ 3.7 Correct classification at week 12 Week 4 69.7 77.1 3.0 (1.6; 5.7) 92.9 62.0 2.4 (1.8; 3.3)
e. ≤ 3.7 Correct classification at week 12 Week 12 79.7 80.0 4.0 (1.6; 9.6) 84.4 45.1 1.5 (1.2; 2.0)
f. ≤ 4 ROC week 12 Week 4 72.7 77.1 3.2 ([1.7; 6.0) 92.9 59.2 2.3 (1.7; 3.1)
f. ≤ 4 ROC week 12 Week 12 86.1 80.0 4.3 (1.8; 10.4) 86.7 37.3 1.4 (1.1; 1.8)
g. ≤ 4.1 Correct classification week 4 Week 4 74.2 77.1 3.2 (1.7; 6.1) 92.9 57.7 2.2 (1.6; 2.9)
g. ≤ 4.1 Correct classification week 4 Week 12 86.1 75.0 3.4 (1.6; 7.4) 86;7 35.3 1.3 (1.1; 1.7)
h. ≤ 4.2 75th percentile at week 4/ROC week 4 Week 4 77.3 74.3 3.0 (1.7; 5.4) 92.9 53.5 2.0 (1.5; 2.6)
h. ≤ 4.2 75th percentile at week 4/ROC week 4 Week 12 87.3 75.0 3.5 (1.6; 7.5) 86.7 33.3 1.3 (1.0; 1.6)
  1. aThe values are those resulting from analysis of the data according to a specific methodology (for example, empiric smallest detectable difference, correct classification probabilities, 75th percentile, ROC curve). bMethodological technique used in the analysis to propose a potential threshold and (in the case of the ROC, 75th percentile and correct classification probabilities) the time point during the study (for example, 4 or 12 weeks after initiation of etanercept therapy) such evaluation has been performed. cThe visit during the study (for example, either 4 or 12 weeks after initiation of etanercept therapy) during which the data collected were used to evaluate the external validity of the proposed thresholds. dPatient's perspective based on the patient acceptable symptom state (PASS) question (X, Y and Z patients answered 'yes' at baseline, week 4 and week 12 respectively: Se, % patients with an absolute RAID score below the proposed cutoff who considered their condition to be acceptable (answering 'yes' to the PASS question) among all patients considering their condition to be acceptable; Spe, % patients with an absolute RAID score above the proposed cutoff who considered their condition to be unacceptable (answering 'no' to the PASS question) among all patients considering their condition to be unacceptable. ePhysician's perspective based on the low disease activity defined by the Disease Activity Score-erythrocyte sedimentation rate (DAS-ESR) < 3 (X, Y, and Z patients had a DAS < 3.2 at baseline, week 4 and week 12 respectively): Se, % patients with an absolute RAID score below the proposed cutoff and in low disease activity (for example, DAS28-ESR ≤ 3.2) at week 12 among all patients with low disease activity at week 12: Spe, % patients with an absolute RAID score above the proposed cutoff and with at least moderately active disease (for example, DAS28-ESR ≥ 3.2) at week 12 among all patients with at least moderately active disease at week 12. ROC, receiver operating characteristic; LR+, positive likelihood ratio.