TABLE 4.
Sensitivity, specificity, positive predictive value, and negative predictive value for screening tools
| Variable | Sensitivitya | Specificitya | Positive predictive valuea | Negative predictive valuea |
|---|---|---|---|---|
| Screening tool | ||||
| Bleeding disorderb | 89 (83–93) | 16 (8–27) | 72 (65–78) | 37 (19–58) |
| Low von Willebrand factor | 73 (39–94) | 12 (8–17) | 4 (2–8) | 89 (71–98) |
| Platelet function defects | 89 (82–94) | 14 (8–23) | 56 (49–63) | 52 (32–71) |
| Screening tool combined with pictorial blood assessment score >185 | ||||
| Bleeding disorderb | 95 (90–98) | 6 (2–15) | 71 (65–77) | 33 (10–65) |
| Low von Willebrand factor | 91 (59–100) | 5 (3–9) | 5 (2–9) | 92 (62–100) |
| Platelet function defects | 94 (88–98) | 5 (2–12) | 55 (48–62) | 42 (15–72) |
| Screening tool combined with ferritin ≤20 ng/mL | ||||
| Bleeding disorderb | 93 (89–97) | 11 (3–19) | 72(66–78) | 39 (16–61) |
| Low von Willebrand factor | 91 (59–100) | 8 (4–12) | 5 (2–8) | 94 (84–100) |
| Platelet function defects | 92 (87–97) | 8 (3–14) | 55 (48–62) | 44 (21–67) |
| Screening tool combined with platelet function analyzer–100 | ||||
| Bleeding disorderb | 89 (84–94) | 16 (7–25) | 72 (66–78) | 37 (19–55) |
| Low von Willebrand factor | 73 (46–99) | 12 (7–16) | 4 (1–7) | 89 (77–100) |
| Platelet function defects | 89 (84–95) | 14 (7–21) | 56 (49–63) | 52 (33–71) |
a
Data are given as percentage (95% confidence interval);
b
Platelet function defects, von Willebrand factor antigen, or von Willebrand factor ristocetin cofactor <50, coagulation defects, or prolonged platelet function analyzer–100 time.