Table 2.
Voided volume range; void trial pass and fail rates; and sensitivity, specificity, PPV, and NPV for chance of successful void trial
| Voided vol, mL | Subjects with voided vol at or above threshold (N = 255) | Void trial result | Successful void trial outcome | ||||
|---|---|---|---|---|---|---|---|
| Pass | Fail | Sensitivity | Specificity | PPV | NPV | ||
| ≥ 50 | 213 | 176 (82.6) | 37 (17.4) | 100 (97.9–100) | 53.2 (41.6–64.5) | 82.6 (76.9–87.5) | 100 (91.5–100) |
| ≥ 75 | 200 | 174 (87.0) | 26 (13.0) | 98.9 (96.0–99.8) | 67.1 (55.6–77.3) | 87.0 (81.5–91.3) | 96.4 (87.5–99.5) |
| ≥ 100 | 194 | 174 (89.7) | 20 (10.3) | 98.9 (96.0–99.8) | 74.7 (63.6–83.8) | 89.7 (84.5–93.6) | 96.7 (88.6–99.5) |
| ≥ 125 | 181 | 168 (92.8) | 13 (7.2) | 95.5 (91.2–98.0) | 83.5 (73.5–90.9) | 92.8 (88.0–96.1) | 89.2 (79.8–95.2) |
| ≥ 150 | 179 | 168 (93.9) | 11 (6.1) | 95.5 (91.2–98.0) | 86.1 (76.5–92.8) | 93.9 (89.3–96.9) | 89.5 (80.3–95.3) |
| ≥ 175 | 171 | 164 (95.9) | 7 (4.1) | 93.2 (88.4–96.4) | 91.1 (82.6–96.4) | 95.9 (91.7–98.3) | 85.7 (76.4–92.4) |
| ≥ 200 | 155 | 151 (97.4) | 4 (2.6) | 85.8 (79.8–90.6) | 94.9 (87.5–98.6) | 97.4 (93.5–99.3) | 75.0 (65.3–83.1) |
| ≥ 225 | 118 | 116 (98.3) | 2 (1.7) | 65.9 (58.4–72.9) | 97.5 (91.1–99.6) | 98.3 (94.0–99.8) | 56.2 (47.5–64.7) |
Pass and fail results are shown as N (percentage), with percentages calculated from the total N for that row (ie, total number of patients who voided at or above the specified voided volume). Sensitivity, specificity, PPV, and NPV are calculated for the ability of voided volume to predict a successful void trial (ie, passing result) and are shown as % (95% confidence interval). NPV, negative predictive value; PPV, positive predictive value.