Table 1.
Descriptive clinical (nongenetic) and demographic characteristics of the study population of warfarin-treated patients from the Veterans Affairs Caribbean Healthcare System, San Juan (PR, USA; derivation cohort) and the independent sample of warfarin-treated Puerto Ricans from the Brownstone Clinic in Hartford (CT, USA; validation cohort).
| Characteristics | Derivation cohort (n = 163) | Validation cohort (n = 55) | ||
|---|---|---|---|---|
| Total (n = 163; 100%) | Noncarriers (n = 49; 30.1%) | Carriers (n = 114; 69.9%) | ||
| Stable warfarin dose (mg/day) | ||||
| Mean (± SD) | 4.5 (1.71) | 5.5 (1.83) | 4.1 (1.48) | 5.0 (2) |
| Range | 1.4–11.0 | 1.6–11.0 | 1.4–10.0 | 1.5–10.0 |
| Age (years) | ||||
| Mean (± SD) | 67.9 (9.0) | 69.0 (7.4) | 67.0 (9.5) | 60.7 (14.4) |
| Range | 31–90 | 55–85 | 31–90 | 23–90 |
| Weight (lbs) | ||||
| Mean (± SD) | 186.0 (33.9) | 185.0 (31.1) | 187.0 (35.2) | 179.0 (41.9) |
| Range | 112–350 | 132–298 | 112–350 | 114.8–277 |
| Height (cm) | ||||
| Mean (± SD) | 67.4 (2.5) | 67.2 (2.5) | 67.5 (2.6) | 62.7 (3.6) |
| Range | 62–76 | 63–73 | 62–76 | 53–69 |
| Indications | ||||
| Atrial fibrillation†/flutter, n (%) | 120 (73.6) | 35 (71.4) | 85 (74.5) | 33 (60) |
| Pulmonary embolism, n (%) | 9 (5.5) | 4 (8.2) | 5 (4.4) | 8 (14.5) |
| Other indication, n (%) | 34 (21) | 10 (20) | 24 (21) | 14 (25.5) |
| Smoker, n (%) | 12 (7.4) | 2 (4.1) | 10 (8.8) | NA |
| Comedications | ||||
| Amiodarone users, n (%) | 16 (9.8) | 5 (10.2) | 11 (9.7) | 2 (3.6) |
| Azoles users, n (%) | 33 (20.2) | 10 (20.4) | 23 (20.2) | NA |
| Statins users, n (%) | 87 (53.4) | 24 (48.9) | 63 (55.3) | NA |
| Race | ||||
| Whites, n (%) | 146 (89.6) | 43 (87.8) | 103 (90.4) | 51 (92.7) |
| Blacks, n (%) | 17 (10.4) | 6 (12.2) | 11 (9.6) | 4 (7.3) |
| INR/dose at day 3 | ||||
| Mean (± SD) | 0.64 (0.39) | 0.56 (0.39) | 0.68 (0.39) | 0.65 (0.53) |
| Range | 0.17–2.27 | 0.17–2.23 | 0.24–2.27 | 0.14–2.47 |
| Target INR | ||||
| Mean (± SD) | 2.5 (0.5) | 2.5 (0.5) | 2.5 (0.5) | 2.5 (0.5) |
| Range | 2–3.5 | 2–3.5 | 2–3.5 | 2–3.5 |
| Gender | ||||
| Male, n (%) | 162 (99.4) | 49 (100) | 113 (99.1) | 20 (36) |
| Females, n (%) | 1 (0.6) | 0 (0) | 1 (0.9) | 35 (64) |
Mean refers to arithmetic mean. All comparisons of the mean values (or percentages) between carriers and noncarriers were not significant, except for the stable warfarin dose variable (p = 0.022). p-values for the difference between the carriers and noncarriers were calculated with the use of the two-tailed Mann–Whitney U/Wilcoxon’s rank-sum test (for warfarin dose, age, height, weight, target INR, INR/dose at third day) and χ2 or Fisher’s exact test (for comedications, smoking status, race, gender and comorbidities). Comedications (brand name in parenthesis when used): amiodarone; statins: simvastatin, rosuvastatin (Crestor®; AstraZeneca, DE, USA), fluvastatin (Lescol®; Novartis Pharmaceuticals Co., NJ, USA) and pravastatin; azoles: fluconazole (Diflucan®; Pfizer Inc., NY, USA), itraconazole and ketoconazole.
Chronic, paroxysmal or postoperative included.
INR: International Normalized Ratio; NA: Information not available; SD: Standard deviation.