Table 4.
Positive predictive values (PPV) of ANCA testing for AAV.
| Immunological marker | All patients PPV% (95%CI) | Inpatients PPV% (95%CI) | Outpatients PPV% (95%CI) |
|---|---|---|---|
| p-ANCA | 13.0 (9.5–16.6) | 14.6 (9.8–19.4) | 17.8 (11.5–24.2) |
| c-ANCA | 67.9 (55.6–80.1) | 57.9 (42.2–73.6) | 88.8 (74.4–100) |
| p-ANCA plus c-ANCA | 20.6 (16.7–24.6) | 21.3 (16.2–26.4) | 25.9 (19.1–32.8) |
| Anti-MPO | 71.7 (61.8–81.8) | 67.4 (53.8–80.9) | 78.1 (63.8–92.4) |
| Anti-PR3 | 76.9 (66.7–87.2) | 69.4 (54.4–84.5) | 86.2 (73.7–98.8) |
| Anti-MPO plus anti-PR3 | 74.1 (66.9–81.3) | 68.3 (58.2–78.4) | 81.9 (72.3–91.6) |
| p-ANCA/MPO | 80.3 (70.4–90.3) | 77.7 (64.2–91.4) | 84.0 (69.6–98.4) |
| c-ANCA/PR3 | 90.5 (81.6–99.4) | 84.6 (70.7–98.5) | 100 |
| p-ANCA/MPO plus c-ANCA/PR3 | 84.5 (77.5–91.5) | 80.6 (70.8–90.5) | 90.2 (81.2–99.3) |