Table 10.
Sensitivity, specificity, PPV, and NPV for tested cases aged more than 5 years
| Case definition | Sensitivity % (95% CI) | Specificity % (95% CI) | PPV % (95% CI) | NPV % (95% CI) |
|---|---|---|---|---|
| World Health Organization epidemic cholera definition | 92.7 (91.2–94.0) | 8.1 (7.1–9.3) | 36.1 (34.5–37.7) | 66.6 (60.9–71.9) |
| Watery stool and dehydration | 92.1 (90.5–93.6) | 17.3 (15.8–18.9) | 38.2 (36.5–40.0) | 79.9 (76.1–83.3) |
| Watery stool and vomiting | 88.8 (86.9–90.5) | 21.0 (19.3–22.7) | 38.3 (36.5–40.1) | 77.2 (73.7–80.4) |
| Watery stool and ≤ 9 stools in last 24 hours | 51.2 (48.3–54.1) | 46.5 (44.4–48.7) | 34.5 (32.3–36.8) | 63.4 (61.0–65.8) |
| Watery stool and (10–25) stools in last 24 hours | 47.0 (44.1–49.9) | 57.3 (55.2–59.4) | 37.7 (35.2–40.2) | 66.3 (64.1–68.4) |
| Watery stool and dry mucous membranes | 72.2 (69.5–74.8) | 34.1 (32.0–36.2) | 37.2 (35.2–39.3) | 69.4 (66.4–72.2) |
| Watery stool and dehydration and vomiting | 84.9 (82.8–86.8) | 26.6 (24.8–28.5) | 39.3 (37.4–41.1) | 75.9 (72.7–78.9) |
| Watery stool and dehydration and ≤ 9 stools in last 24 hours | 46.7 (43.8–49.6) | 58.5 (56.3–60.6) | 38.7 (36.1–41.3) | 66.2 (64.0–68.3) |
| Watery stool and dehydration and (10–25) stools in last 24 hours | 46.7 (43.8–49.6) | 58.3 (56.2–60.4) | 37.9 (35.4–40.5) | 66.7 (64.5–68.9) |
| Watery stool and (dehydration or vomiting) | 96.7 (95.6–97.6) | 10.7 (9.4–12.1) | 37.7 (36.0–39.4) | 85.3 (80.6–89.2) |
| Watery stool and (dehydration or rice water stools) | 95.9 (94.7–96.9) | 14.6 (13.1–16.1) | 38.6 (36.9–40.4) | 86.4 (82.5–89.7) |
| Watery stool and (dehydration or rice water stools or vomiting) | 97.2 (96.1–98.0) | 10.0 (8.8–11.3) | 37.8 (36.1–39.6) | 86.2 (81.4–90.2) |
| Watery stool and vomiting and dry mucous membranes | 68.6 (65.8–71.3) | 40.1 (38.0–42.3) | 38.3 (36.2–40.5) | 70.2 (67.5–72.8) |
| Rice water stools | 74.8 (72.4–77.0) | 36.6 (34.7–38.6) | 40.1 (38.2–42.0) | 71.9 (69.3–74.4) |
| Rice water stools and dehydration | 75.6 (73.1–77.9) | 36.1 (34.2–38.2) | 39.8 (37.8–41.8) | 72.6 (69.9–75.2) |
| Rice water stools and vomiting | 73.4 (70.9–75.8) | 41.2 (39.2–43.3) | 41.1 (39.1–43.2) | 73.5 (70.9–75.9) |
| Rice water stools and ≤ 9 stools in last 24 hours | 40.2 (37.4–43.1) | 70.2 (68.2–72.1) | 42.7 (39.8–45.7) | 68.0 (66.0–69.9) |
| Rice water stools and (10–25) stools in last 24 hours | 40.3 (37.5–43.2) | 62.9 (60.8–65.0) | 37.5 (34.9–40.3) | 65.6 (63.5–67.6) |
| Rice water stools and dry mucous membranes | 60.9 (58.0–63.8) | 46.0 (43.9–48.2) | 38.1 (35.8–40.4) | 68.4 (65.9–70.9) |
| Rice water stools and dehydration and vomiting | 70.8 (68.2–73.4) | 42.5 (40.4–44.6) | 40.9 (38.8–43.0) | 72.2 (69.7–74.6) |
| Rice water stools and dehydration and ≤ 9 stools in last 24 hours | 38.5 (35.6–41.4) | 69.4 (67.2–71.5) | 43.0 (40.0–46.2) | 65.2 (63.1–67.3) |
| Rice water stools and dehydration and (10–25) stools in last 24 hours | 39.0 (36.2–41.9) | 66.0 (64.0–68.0) | 37.3 (34.6–40.1) | 67.6 (65.6–69.5) |
| Rice water stools and vomiting and dry mucous membranes | 58.1 (55.2–61.1) | 51.1 (48.9–53.3) | 39.3 (37.0–41.8) | 69.1 (66.7–71.4) |
CI = confidence interval; NPV = negative predictive value; PPV = positive predictive value.