Sensitivity | Specificity | PPV (%) | NPV (%) | RR | 95% CI | |
---|---|---|---|---|---|---|
(%) | (%) | |||||
The results of the positive predictive value (PPV) are highlighted. The patient group tested comprised 102 patients with suspected RA who were referred to a rheumatologist. Twenty eight of them fulfilled the ACR criteria for RA (pretest probability of 27%). | ||||||
PPV, positive predictive value; NPV, negative predictive value; RR, relative risk; 95% CI, 95% confidence interval for relative risk; anti-CCP, anti-CCP values above normal (<2 U/l); RF, rheumatoid factor above normal (<10 U/l); CRP, C reactive protein value above normal (<5 mg/l), ESR, erythrocyte sedimentation rate >20 mm/1st h; morning stiffness, morning stiffness of at least 60 minutes; polyarticular pain, pain in at least four joints or muscular regions. | ||||||
Anti-CCP | 43 | 86 | 55 | 80 | 2.7 | 1.5 to 4.9 |
Anti-CCP plus ESR | 21 | 95 | 60 | 76 | 2.5 | 1.3 to 4.7 |
Anti-CCP plus RF | 36 | 91 | 59 | 79 | 2.8 | 1.6 to 4.9 |
Anti-CCP plus CRP | 25 | 97 | 78 | 77 | 3.4 | 2.1 to 5.8 |
Anti-CCP plus polyarticular pain | 43 | 95 | 78 | 81 | 4.0 | 2.4 to 6.8 |
Anti-CCP plus morning stiffness | 29 | 99 | 89 | 78 | 4.1 | 2.7 to 6.5 |
RF | 46 | 78 | 45 | 79 | 2.2 | 1.2 to 4.0 |
RF plus ESR | 18 | 93 | 50 | 75 | 2.0 | 0.9 to 4.1 |
RF plus CRP | 18 | 96 | 63 | 76 | 2.6 | 1.3 to 4.9 |
RF plus polyarticular pain | 46 | 92 | 68 | 82 | 3.8 | 2.2 to 6.6 |
RF plus morning stiffness | 30 | 97 | 80 | 78 | 3.7 | 2.2 to 6.0 |