Table 4.
Predictive value for the progression from UA to RA within one year using different cut-off values for erosions in hands
| Number of erosive joints | n | PPV | (95% CI) | NPV | (95% CI) | Specificity | (95% CI) | Sensitivity | (95% CI) | LR+ | LR- | AUC (SEM) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≥1 | 103 | 44 | 34-53 | 72 | 68-77 | 84 | 80-88 | 28 | 21-35 | 1.7 | 0.86 | 0.56 (0.028) |
| ≥2 | 38 | 55 | 40-71 | 71 | 67-75 | 95 | 93-98 | 13 | 8-18 | 2.8 | 0.91 | 0.54 (0.028) |
| ≥3 | 18 | 56 | 33-79 | 70 | 66-74 | 98 | 96-99 | 6 | 3-10 | 2.8 | 0.96 | 0.52 (0.028) |
| ≥4 | 9 | 67 | 36-98 | 70 | 66-74 | 99 | 98-100 | 4 | 1-7 | 4.5 | 0.97 | 0.52 (0.028) |
| ≥5 | 7 | 71 | 38-100 | 70 | 66-74 | 99 | 99-100 | 3 | 0-6 | 5.6 | 0.97 | 0.51 (0.028) |
n = number of UA patients positive for this cutoff.
AUC = area under the curve; CI = confidence interval; LR+ = positive likelihood ratio; LR- = negative likelihood ratio; NPV = negative predictive value; PPV = positive predictive value; RA = rheumatoid arthritis; SEM = standard error of measurement; UA = undifferentiated arthritis.