Number of clotting defects and exposure-response relationship of common clotting abnormalities*
| Prevalence in cases (n=194) (%) | Prevalence in controls (n=250) (%) | OR† (95% CI) | OR‡ (95% CI) | |
|---|---|---|---|---|
| Number of clotting defects§ | ||||
| 0 | 41 (21.1) | 134 (53.6) | 1.00 | 1.00 |
| 1 | 116 (59.8) | 99 (39.6) | 3.53 (2.25 to 5.57) | 3.84 (2.31 to 6.40) |
| 2 or greater | 37 (19.1) | 17 (6.8) | 6.31 (3.16 to 12.60) p for trend <0.0001 | 5.74 (2.67 to 12.34) p for trend <0.0001 |
| Factor VIII level (IU/dL) | ||||
| ≤165 | 82 (38.9) | 211 (82.4) | 1.00 | 1.00 |
| 166–250 | 107 (50.7) | 41 (16.0) | 6.54 (4.14 to 10.31) | 6.75(4.04 to 11.27) |
| ≥251 | 22 (10.4) | 4 (1.6) | 14.21 (4.65 to 43.40) p for trend<0.001 | 9.43 (2.82 to 31.52) p for trend<0.001 |
| Free protein S (IU/dL) | ||||
| ≥66 | 186 (95.8) | 243 (97.2) | 1.00 | 1.00 |
| 56–65 | 5 (2.6) | 4 (1.6) | 1.55 (0.39 to 6.19) | 1.18 (0.24 to 5.80) |
| ≤55 | 3 (1.6) | 3 (1.2) | 1.16 (0.21 to 6.49) p for trend=0.662 | 1.26 (0.21 to 7.56) p for trend=0.701 |
| D-dimer | ||||
| ≤180 | 80 (41.2) | 151 (60.4) | 1.00 | 1.00 |
| 181–1000 | 101 (52.1) | 89 (35.6) | 1.91 (1.26 to 2.90) | 1.77 (1.11 to 2.81) |
| ≥1001 | 13 (6.7) | 10 (4.0) | 2.51 (1.02 to 6.19) p for trend=0.003 | 3.70 (1.33 to 10.33) p for trend=0.003 |
| Clot lysis time (min) | ||||
| ≤240 | 46 (23.7) | 85 (34.0) | 1.00 | 1.00 |
| 241–340 | 106 (54.6) | 152 (60.8) | 1.40 (0.89 to 2.21) | 1.17 (0.70 to 1.96) |
| ≥341 | 42 (21.7) | 13 (5.2) | 6.80 (3.20 to 14.44) p for trend<0.001 | 5.64 (2.48 to 12.85) p for trend<0.001 |
*Analyses performed after exclusion of individuals currently on warfarin.
†ORs adjusted for age category and sex.
‡ORs adjusted for age category, sex, smoking status and highly sensitive C reactive protein category.
§Sum of the number of individual clotting defects found on laboratory testing.