Calculated sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (−LR) of PGA cut-offs using coinciding SDAI remission as outcome, in patients fulfilling SJC28, TJC28 and CRP all ≤1
| 6 months | 12 months | ||||||||||
| Definition | Cut-off | Sensitivity | Specificity | +LR | −LR | Definition | Cut-off | Sensitivity | Specificity | +LR | −LR |
| Early | 1 | 88.1 (83.1–92.1) | 87.4 (79.7 to 92.9) | 7.0 (4.3–11.4) | 0.14 (0.09–0.2) | Early | 1 | 87.2 (83.2–90.4) | 85.6 (78.9 to 90.9) | 6.1 (4.1–9.0) | 0.2 (0.1–0.2) |
| 1.1 | 90 (85.2–93.6) | 84.7 (76.6 to 90.8) | 5.9 (3.8–9.1) | 0.1 (0.08–0.2) | 1.1* | 89.1 (85.4–92.1) | 84.3 (77.3 to 89.7) | 5.7 (3.9–8.2) | 0.1 (0.10–0.2) | ||
| 1.2 | 92.7 (88.4–95.8) | 82.9 (74.6 to 89.4) | 5.4 (3.6–8.2) | 0.1 (0.05–0.1) | 1.2 | 89.9 (86.4–92.9) | 81.5 (74.2 to 87.4) | 4.9 (3.5–6.8) | 0.1 (0.09–0.2) | ||
| 1.3 | 94.1 (90.1–96.8) | 82.9 (74.6 to 89.4) | 5.5 (3.6–8.3) | 0.1 (0.04–0.1) | 1.3 | 91.9 (88.6–94.5) | 78.8 (71.2 to 85.1) | 4.3 (3.2–5.9) | 0.1 (0.07–0.1) | ||
| 1.4 | 95.9 (92.3–98.1) | 81.1 (72.5 to 87.9) | 5.1 (3.4–7.5) | 0.1 (0.03–0.10) | 1.4 | 93.6 (90.5–95.9) | 76.7 (69.0 to 83.3) | 4 (3.0–5.4) | 0.1 (0.06–0.1) | ||
| 1.5 | 96.8 (93.5–98.7) | 80.2 (71.5 to 87.1) | 4.9 (3.4–7.1) | 0.04 (0.02–0.08) | 1.5 | 93.9 (90.8–96.1) | 73.3 (65.3 to 80.3) | 3.5 (2.7–4.6) | 0.1 (0.06–0.1) | ||
| 1.6* | 97.3 (94.1–99.0) | 79.3 (70.5 to 86.4) | 4.7 (3.3–6.8) | 0.04 (0.02–0.08) | 1.6 | 95 (92.2–97.0) | 71.2 (63.2 to 78.4) | 3.3 (2.6–4.3) | 0.1 (0.04–0.1) | ||
| 1.7 | 98.2 (95.4–99.5) | 77.5 (68.6 to 84.9) | 4.4 (3.1–6.2) | 0.02 (0.009–0.06) | 1.7 | 96.1 (93.5–97.8) | 70.6 (62.4 to 77.8) | 3.3 (2.5–4.2) | 0.1 (0.03–0.09) | ||
| 1.8 | 98.2 (95.4–99.5) | 73.9 (64.7 to 81.8) | 3.8 (2.7–5.1) | 0.03 (0.009–0.07) | 1.8 | 96.4 (93.9–98.1) | 69.2 (61.0 to 76.5) | 3.1 (2.5–4.0) | 0.1 (0.03–0.09) | ||
| 1.9 | 98.6 (96.0–99.7) | 71.2 (61.8 to 79.4) | 3.4 (2.6–4.6) | 0.02 (0.006–0.06) | 1.9 | 96.7 (94.2–98.3) | 67.1 (58.9 to 74.7) | 2.9 (2.3–3.7) | 0.1 (0.03–0.09) | ||
| 2 | 98.6 (96.0–99.7) | 68.5 (59.0 to 77.0) | 3.1 (2.4–4.1) | 0.02 (0.01–0.06) | 2 | 96.9 (94.6–98.5) | 61.6 (53.2 to 69.6) | 2.5 (2.1–3.1) | 0.1 (0.03–0.09) | ||
| Established | 1 | 73.1 (59.0–84.4) | 73.8 (60.9 to 84.2) | 2.8 (1.8–4.4) | 0.4 (0.2–0.6) | Established | 1 | 83.9 (75.8–90.2) | 90.3 (82.4 to 95.5) | 8.7 (4.6–16.2) | 0.2 (0.1–0.3) |
| 1.1 | 75 (61.1–86.0) | 73.8 (60.9 to 84.2) | 2.9 (1.8–4.5) | 0.3 (0.2–0.6) | 1.1 | 83.9 (75.8–90.2) | 89.3 (81.1 to 94.7) | 7.8 (4.3–14.1) | 0.2 (0.1–0.3) | ||
| 1.2 | 76.9 (63.2–87.5) | 72.1 (59.2 to 82.9) | 2.8 (1.8–4.2) | 0.3 (0.2–0.5) | 1.2 | 85.7 (77.8–91.6) | 87.1 (78.5 to 93.2) | 6.6 (3.9–11.3) | 0.2 (0.1–0.3) | ||
| 1.3* | 84.6 (71.9–93.1) | 68.9 (55.7 to 80.1) | 2.7 (1.8–4.0) | 0.2 (0.1–0.4) | 1.3 | 88.4 (81.0–93.7) | 85 (76.0 to 91.5) | 5.9 (3.6–9.6) | 0.1 (0.08–0.2) | ||
| 1.4 | 84.6 (71.9–93.1) | 67.2 (54.0 to 78.7) | 2.6 (1.8–3.8) | 0.2 (0.1–0.4) | 1.4 | 91.1 (84.2–95.6) | 83.9 (74.8 to 90.7) | 5.7 (3.5–9.0) | 0.1 (0.06–0.2) | ||
| 1.5 | 86.5 (74.2–94.4) | 62.3 (49.0 to 74.4) | 2.3 (1.6–3.2) | 0.2 (0.1–0.4) | 1.5* | 93.8 (87.5–97.5) | 80.7 (71.1 to 88.1) | 4.8 (3.2–7.4) | 0.1 (0.04–0.2) | ||
| 1.6 | 88.5 (76.6–95.6) | 59 (45.7 to 71.4) | 2.2 (1.6–3.0) | 0.2 (0.09–0.4) | 1.6 | 93.8 (87.5–97.5) | 79.6 (69.9 to 87.2) | 4.6 (3.1–6.9) | 0.1 (0.04–0.2) | ||
| 1.7 | 90.4 (79.0–96.8) | 54.1 (40.8 to 66.9) | 2 (1.5–2.6) | 0.2 (0.07–0.4) | 1.7 | 95.5 (89.9–98.5) | 76.3 (66.4 to 84.5) | 4 (2.8–5.8) | 0.1 (0.02–0.1) | ||
| 1.8 | 92.3 (81.5–97.9) | 52.5 (39.3 to 65.4) | 1.9 (1.5–2.6) | 0.2 (0.06–0.4) | 1.8 | 96.4 (91.1–99.0) | 74.2 (64.1 to 82.7) | 3.7 (2.6–5.3) | 0.05 (0.02–0.1) | ||
| 1.9 | 94.2 (84.1–98.8) | 47.5 (34.6 to 60.7) | 1.8 (1.4–2.3) | 0.1 (0.04–0.4) | 1.9 | 96.4 (91.1–99.0) | 73.1 (62.9 to 81.8) | 3.6 (2.6–5.0) | 0.05 (0.02–0.1) | ||
| 2 | 96.2 (86.8–99.5) | 45.9 (33.1 to 59.2) | 1.8 (1.4–2.3) | 0.1 (0.02–0.3) | 2 | 97.3 (92.4–99.4) | 69.9 (59.5 to 79.0) | 3.2 (2.4–4.4) | 0.04 (0.01–0.1) | ||
| All | 1 | 85.2 (80.4–89.2) | 82.6 (76.0 to 87.9) | 4.9 (3.5–6.8) | 0.2 (0.1–0.2) | All | 1 | 86.4 (82.9–89.4) | 87.5 (82.6 to 91.4) | 6.9 (4.9–9.6) | 0.2 (0.1–0.2) |
| 1.1 | 87.1 (82.5–90.8) | 80.8 (74.1 to 86.4) | 4.5 (3.3–6.2) | 0.2 (0.1–0.2) | 1.1* | 88.1 (84.8–90.9) | 85.4 (80.2 to 89.6) | 6 (4.4–8.2) | 0.1 (0.1–0.2) | ||
| 1.2 | 87.5 (82.9–91.2) | 80.2 (73.5 to 85.9) | 4.4 (3.3–6.0) | 0.2 (0.1–0.2) | 1.2 | 88.3 (85.0–91.1) | 85.4 (80.2 to 89.6) | 6 (4.4–8.2) | 0.1 (0.1–0.2) | ||
| 1.3 | 92.3 (88.4–95.1) | 77.9 (71.0 to 83.9) | 4.2 (3.1–5.5) | 0.1 (0.07–0.2) | 1.3 | 89.6 (86.5–92.2) | 82.9 (77.5 to 87.4) | 5.2 (3.9–6.9) | 0.1 (0.1–0.2) | ||
| 1.4 | 87.5 (82.9–91.2) | 80.2 (73.5 to 85.9) | 4.4 (3.3–6.0) | 0.2 (0.1–0.2) | 1.4 | 91.7 (88.8–94.0) | 80.8 (75.2 to 85.6) | 4.8 (3.7–6.2) | 0.1 (0.08–0.1) | ||
| 1.5 | 94.8 (91.5–97.1) | 73.8 (66.6 to 80.2) | 3.6 (2.8–4.7) | 0.1 (0.04–0.1) | 1.5 | 93.8 (91.3–95.8) | 76.2 (70.2 to 81.4) | 3.9 (3.1–4.9) | 0.1 (0.06–0.1) | ||
| 1.6* | 95.6 (92.4–97.7) | 72.1 (64.8 to 78.7) | 3.4 (2.7–4.4) | 0.1 (0.04–0.1) | 1.6 | 94.7 (92.2–96.5) | 74.5 (68.5 to 79.9) | 3.7 (3.0–4.6) | 0.1 (0.05–0.1) | ||
| 1.7 | 96.7 (93.8–98.5) | 69.2 (61.7 to 76.0) | 3.1 (2.5–3.9) | 0.05 (0.03–0.09) | 1.7 | 94.9 (92.5–96.7) | 74.5 (68.5 to 79.9) | 3.7 (3.0–4.6) | 0.1 (0.05–0.1) | ||
| 1.8 | 97.1 (94.3–98.7) | 66.3 (58.7 to 73.3) | 2.9 (2.3–3.6) | 0.05 (0.02–0.09) | 1.8 | 96.4 (94.3–97.9) | 71.1 (64.9 to 76.8) | 3.3 (2.7–4.1) | 0.1 (0.03–0.08) | ||
| 1.9 | 97.8 (95.2–99.2) | 62.8 (55.1 to 70.0) | 2.6 (2.2–3.2) | 0.04 (0.02–0.08) | 1.9 | 96.4 (94.3–97.9) | 70.7 (64.5 to 76.4) | 3.3 (2.7–4.0) | 0.1 (0.03–0.08) | ||
| 2 | 98.2 (95.7–99.4) | 60.5 (52.7 to 67.8) | 2.5 (2.1–3.0) | 0.03 (0.01–0.07) | 2 | 97 (95.1–98.4) | 64.9 (58.4 to 70.9) | 2.8 (2.3–3.3) | 0.05 (0.03–0.08) | ||
Cut-offs (to be interpreted as ≤) marked with * were proposed in the classification and regression tree (CART) analyses.
CRP, C reactive protein; PGA, patient global assessment; SDAI, Simplified Disease Activity Index; SJC, swollen joint counts; TJC, tender joint counts .