Table 1.
Suppression of urinary 11-dehydro-thromboxane B2 (U-TXM) at follow-up with allocation to daily low-dose aspirin
| Percentage achieving effective suppression* by treatment allocation | Geometric mean U-TXM (95% CI) by treatment allocation | Reduction in U-TXM with aspirin (95% CI) | ||||
|---|---|---|---|---|---|---|
| Group | N | Aspirin | Placebo | Aspirin | Placebo | |
| Random sample | ||||||
| All | 150 | 62/76 (82%) | 5/74 (7%)† | 979 (854 − 1122) | 3322 (2874 − 3839) | 71% (64 to 76%)† |
| Non-adherent | 16 | 3/7 (43%) | 4/9 (44%)‡ | 1712 (845 − 3468) | 1686 (860 − 3305) | − 2% (− 82 to 43%)‡ |
| Adherent | 132 | 59/69 (86%) | 1/63 (2%) | 925 (814 − 1050) | 3655 (3221 − 4147) | 75% (69 to 79%) |
| Time of ingestion relative to sample | ||||||
| ≤ 12 h before | 100 | 45/52 (87%) | 1/48 (2%) | 896 (768 − 1044) | 3517 (3039 − 4070) | 75% (69 to 79%) |
| > 12 h before | 28 | 12/14 (86%) | 0/14 (0%) | 1015 (801 − 1285) | 4104 (3139 − 5365) | 75% (63 to 83%) |
| Unknown | 4 | 2/3 (67%) | 0/1 (0%) | 1042 (536 − 2024) | 4563 | 77% (14 to 94%) |
| Adherent sample | ||||||
| Adherent | 198 | 66/93 (71%) | 4/105 (4%) | 1366 (1233 − 1513) | 4511 (4114 − 4947) | 70% (65 to 74%) |
| Time of ingestion relative to sample | ||||||
| ≤ 12 h before | 100 | 38/50 (76%) | 2/50 (4%) | 1390 (1220 − 1584) | 4286 (3781 − 4860) | 68% (61 to 73%) |
| > 12 h before | 98 | 28/43 (65%) | 2/55 (4%) | 1338 (1137 − 1576) | 4726 (4134 − 5403) | 72% (66 to 77%) |
| Either sample | ||||||
| Adherent | 330 | 125/162 (77%) | 5/168 (3%) | 1157 (1062 − 1260) | 4169 (3864 − 4498) | 72% (69 to 75%) |
| Time of ingestion relative to sample | ||||||
| ≤ 12 h before | 200 | 83/102 (81%) | 3/98 (3%)§ | 1111 (996 − 1239) | 3891 (3529 − 4289) | 71% (67 to 75%)§ |
| > 12 h before | 126 | 40/57 (70%) | 2/69 (3%) | 1250 (1088 − 1436) | 4593 (4075 − 5176) | 72% (67 to 77%) |
| Unknown | 4 | 2/3 (67%) | 0/1 (0%) | 1042 (536 − 2024) | 4563 | 77% (14 to 94%) |
CI confidence interval, U-TXM urinary 11-dehydro-thromboxane B2 (pg/mg creatinine). *Effective suppression = U-TXM < 1500 pg/mg creatinine
†P < 0.0001 for difference by aspirin vs placebo
‡P < 0.0001 for heterogeneity in the difference by adherence to randomized treatment
§P > 0.5 for heterogeneity in the difference by ≤ 12 versus > 12 h from ingestion to urine sample in those adherent to randomized treatment