Prediction of laparoscopically diagnosed PID: sensitivity and specificity of signs and symptoms, likelihood ratios and post-test probabilities (pretest probability = 79%)
| Signs and symptoms | Sensitivity (%) | Specificity (%) | Laparoscopically diagnosed PID | Likelihood ratio* (positive) | Post-test probability | |
|---|---|---|---|---|---|---|
| (95% CI) | (95% CI) | Present (n = 494) | Absent (n = 129) | |||
| No (%) | No (%) | |||||
| *Likelihood ratio interpretation: >10 and <0.1 (large difference between pretest and post-test probability), 5–10 and 0.1–0.2 (moderate), 2–5 and 0.5–0.2 (small), 1–2 and 0.05–1 (small and rarely important).14 | ||||||
| Vaginal discharge | 74 (69.99 to 77.90) | 24 (16.95 to 32.34) | 366 (74) | 98 (76) | 0.98 | 0.79 |
| Fever | 47 (42.49 to 51.47) | 64 (55.43 to 72.58) | 234 (47) | 47 (36) | 1.30 | 0.83 |
| Vomiting | 14 (11.03 to 17.34) | 88 (81.55 to 93.34) | 68 (14) | 16 (12) | 1.11 | 0.81 |
| Menstrual irregularity | 45 (40.49 to 49.45) | 57 (48.36 to 66.03) | 223 (45) | 56 (43) | 1.04 | 0.80 |
| Ongoing bleeding | 25 (21.34 to 29.17) | 77 (68.49 to 83.73) | 124 (25) | 29 (22) | 1.12 | 0.81 |
| Urinary symptoms | 35 (30.81 to 39.41) | 64 (55.43 to 72.58) | 173 (35) | 46 (36) | 0.98 | 0.79 |
| Proctitis symptoms | 10 (7.43 to 12.90) | 92 (86.21 to 96.22) | 50 (10) | 10 (8) | 1.31 | 0.83 |
| Tenderness of pelvic organs on bimanual examination | 99 (97.65 to 99.67) | 0.007 (<0.001 to 2.84) | 489 (99) | 128 (99) | 1.00 | 0.79 |
| Palpable adnexal mass or swelling | 52 (47.52 to 56.51) | 70 (61.06 to 77.54) | 258 (52) | 39 (30) | 1.73 | 0.84 |
| Erythrocyte sedimentation rate ⩾15 mm in 1st hour | 81 (77.23 to 84.34) | 33 (25.28 to 42.17) | 402 (81) | 86 (66) | 1.22 | 0.82 |