Table 1.
Minimal clinically important different (MCID) to predict change in VAS severity categories.
| Scale | MCID: increase from baseline (# points) | Positive predictive value | |||||||
|---|---|---|---|---|---|---|---|---|---|
| VAS bad effects: 0 | N | VAS bad effects: 1–40 | N | VAS bad effects: 41–80 | N | VAS bad effects: 81–100 | N | ||
| % (95% CI) | % (95% CI) | % (95% CI) | % (95% CI) | ||||||
| SOWS | 8 | 5.1 (0.0–16.2) | 14 | 20.7 (10.2–31.3) | 57 | 33.7 (24.1–43.3) | 93 | 40.6 (31.5–49.7) | 112 |
| 9 | 4.8 (0.0–16.9) | 12 | 18.7 (10.2–31.2) | 47 | 33.7 (23.7–43.7) | 85 | 42.9 (33.6–52.2) | 108 | |
| 10 | 5.3 (0.0–18.0) | 12 | 15.5 (3.5–27.5) | 35 | 33.6 (23.0–44.2) | 76 | 45.6 (36.0–55.2) | 103 | |
| 11 | 4.7 (0.0–17.8) | 10 | 15.2 (2.7–27.6) | 32 | 33.2 (22.2–44.2) | 70 | 46.9 (36.0–55.2) | 99 | |
| 12 | 4.1 (0.0–17.8) | 8 | 13.2 (0.0–26.2) | 26 | 34.0 (22.7–45.3) | 67 | 48.7 (38.7–56.7) | 96 | |
| COWS | 4 | 7.5 (0.0–17.1) | 29 | 27.8 (19.4–36.2) | 108 | 31.2 (22.9–39.4) | 121 | 33.5 (25.4–41.2) | 130 |
| 5 | 6.1 (0.0–16.5) | 20 | 24.8 (15.4–34.2) | 81 | 31.9 (22.9–40.1) | 104 | 37.1 (28.5–45.7) | 121 | |
| 6 | 4.2 (0.0–15.5) | 12 | 22.5 (12.3–32.7) | 64 | 33.7 (24.2–43.1) | 96 | 39.6 (30.1–48.6) | 113 | |
| 7 | 3.3 (0.0–15.7) | 8 | 19.6 (9.3–30.1) | 48 | 34.7 (24.5–44.8) | 85 | 42.4 (32.9–51.9) | 104 | |
| 8 | 2.4 (0.0–15.8) | 5 | 18.4 (6.1–30.1) | 38 | 32.0 (20.7–43.3) | 66 | 47.1 (37.2–57.0) | 97 | |
| VAS sick: 0 | N | VAS sick: 1–40 | N | VAS sick: 41–80 | N | VAS sick: 81–100 | N | ||
| % (95% CI) | % (95% CI) | % (95% CI) | % (95% CI) | ||||||
| SOWS | 8 | 12.3 (1.0–23.3) | 34 | 29.0 (19.1–40.0) | 80 | 25.7 (15.6–35.8) | 71 | 33.0 (23.3–42.6) | 91 |
| 9 | 11.9 (0.0–23.4) | 30 | 26.2 (15.6–36.8) | 66 | 26.2 (15.6–36.8) | 66 | 35.7 (25.8–45.6) | 90 | |
| 10 | 11.1 (0.0–23.4) | 25 | 24.3 (12.9–35.6) | 66 | 26.5 (15.3–37.7) | 60 | 38.1 (27.8–48.3) | 86 | |
| 11 | 11.4 (0.0–24.1) | 24 | 23.2 (11.4–35.0) | 49 | 26.5 (14.9–38.1) | 56 | 38.9 (28.3–49.5) | 82 | |
| 12 | 10.7 (2.0–23.9) | 21 | 21.3 (8.9–33.6) | 42 | 27.4 (15.5–39.2) | 54 | 40.6 (29.8–51.3) | 80 | |
| COWS | 4 | 14.9 (5.7–24.1) | 58 | 32.5 (24.3–40.1) | 126 | 25.3 (16.7–33.9) | 98 | 27.3 (18.8–35.8) | 106 |
| 5 | 14.1 (4.0–24.1) | 46 | 28.5 (19.3–37.7) | 93 | 26.7 (17.4–36.0) | 87 | 30.7 (21.7–39.7) | 100 | |
| 6 | 13.0 (2.2–23.8) | 37 | 24.9 (14.8–35.0) | 71 | 28.4 (18.6–38.2) | 81 | 33.7 (24.2–43.2) | 96 | |
| 7 | 11.0 (0.0–22.8) | 27 | 24.9 (14.0–35.7) | 61 | 27.8 (17.2–38.4) | 68 | 36.3 (26.3–46.2) | 89 | |
| 8 | 11.0 (0.0–24.1) | 23 | 22.3 (10.2–34.3) | 46 | 25.7 (13.9–37.5) | 53 | 40.8 (30.2–51.3) | 83 | |
CI, confidence interval; COWS, Clinical Opiate Withdrawal Scale; SOWS, Subjective Opiate Withdrawal Scale; VAS, Visual Analog Scale.