Baseline characteristics of participants
| Characteristic . | Low intensity, n = 337 . | Conventional intensity, n = 324 . | Total, N = 661 . |
|---|---|---|---|
| Mean age, y (SD) | 57 (15) | 57 (15) | 57 (15) |
| Female sex, n (%) | 140 (42) | 149 (46) | 289 (44) |
| Previous episodes of VTE, n (%) | |||
| 1 | 90 (27) | 86 (27) | 176 (27) |
| 2 | 172 (51) | 165 (51) | 337 (51) |
| 3 | 49 (15) | 57 (18) | 106 (16) |
| 4 or more | 26 (8) | 15 (5) | 41 (6) |
| Treated for 3-4 months before enrollment, n (%) | 133 (39) | 130 (40) | 263 (40) |
| Months of warfarin (INR 2.0-3.0) before enrollment, mean (SD) | 12.0 (16.5) | 12.8 (18.3) | 12.4 (17.4) |
| Most recent type of VTE, n (%) | |||
| Deep vein thrombosis only | 231 (69) | 207 (64) | 438 (66) |
| Pulmonary embolism | 106 (31) | 117 (36) | 223 (34) |
| Factor V Leiden, n/N (%) | 91/328 (27.7) | 80/318 (25.2) | 171/646 (26.5) |
| Heterozygous | 84 (25.6) | 77 (24.2) | 161 (24.9) |
| Homozygous | 7 (2.1) | 3 (1.0) | 10 (1.6) |
| Prothrombin gene mutation, n/N (%) | 32/327 (9.8) | 28/317 (8.8) | 60/644 (9.3) |
| Heterozygous | 32 (9.8) | 26 (8.2) | 58 (9.0) |
| Homozygous | 0 (0) | 2 (0.6) | 2 (0.3) |
| Antiphospholipid antibody, n/N (%) | 28/337 (8.3) | 26/324 (8.0) | 54/661 (8.2) |
| Anticardiolipin antibody | 20 (5.9) | 20 (6.2) | 40 (6.1) |
| Lupus anticoagulant | 9 (2.7) | 10 (3.1) | 19 (2.9) |
| Antithrombin deficiency, n/N (%) | 15/329 (4.6) | 8/316 (2.5) | 23/645 (3.6) |
| Elevated factor VIII, n/N (%) | 26/335 (7.8) | 41/324 (12.7) | 67/659 (10.2) |
| Elevated factor XI, n/N (%) | 28/331 (8.5) | 38/316 (12.0) | 66/647 (10.2) |
| Elevated homocysteine, n/N (%) | 27/325 (8.3) | 37/313 (11.8) | 64/638 (10.0) |
| No. of abnormalities, n (%) | |||
| None | 147 (43.6) | 133 (41.0) | 280 (42.4) |
| 1 | 137 (40.6) | 133 (41.0) | 270 (40.8) |
| 2 | 44 (13.1) | 47 (14.6) | 91 (13.8) |
| 3 | 7 (2.1) | 8 (2.5) | 15 (2.3) |
| 4 | 2 (0.6) | 3 (0.9) | 5 (0.8) |
| Characteristic . | Low intensity, n = 337 . | Conventional intensity, n = 324 . | Total, N = 661 . |
|---|---|---|---|
| Mean age, y (SD) | 57 (15) | 57 (15) | 57 (15) |
| Female sex, n (%) | 140 (42) | 149 (46) | 289 (44) |
| Previous episodes of VTE, n (%) | |||
| 1 | 90 (27) | 86 (27) | 176 (27) |
| 2 | 172 (51) | 165 (51) | 337 (51) |
| 3 | 49 (15) | 57 (18) | 106 (16) |
| 4 or more | 26 (8) | 15 (5) | 41 (6) |
| Treated for 3-4 months before enrollment, n (%) | 133 (39) | 130 (40) | 263 (40) |
| Months of warfarin (INR 2.0-3.0) before enrollment, mean (SD) | 12.0 (16.5) | 12.8 (18.3) | 12.4 (17.4) |
| Most recent type of VTE, n (%) | |||
| Deep vein thrombosis only | 231 (69) | 207 (64) | 438 (66) |
| Pulmonary embolism | 106 (31) | 117 (36) | 223 (34) |
| Factor V Leiden, n/N (%) | 91/328 (27.7) | 80/318 (25.2) | 171/646 (26.5) |
| Heterozygous | 84 (25.6) | 77 (24.2) | 161 (24.9) |
| Homozygous | 7 (2.1) | 3 (1.0) | 10 (1.6) |
| Prothrombin gene mutation, n/N (%) | 32/327 (9.8) | 28/317 (8.8) | 60/644 (9.3) |
| Heterozygous | 32 (9.8) | 26 (8.2) | 58 (9.0) |
| Homozygous | 0 (0) | 2 (0.6) | 2 (0.3) |
| Antiphospholipid antibody, n/N (%) | 28/337 (8.3) | 26/324 (8.0) | 54/661 (8.2) |
| Anticardiolipin antibody | 20 (5.9) | 20 (6.2) | 40 (6.1) |
| Lupus anticoagulant | 9 (2.7) | 10 (3.1) | 19 (2.9) |
| Antithrombin deficiency, n/N (%) | 15/329 (4.6) | 8/316 (2.5) | 23/645 (3.6) |
| Elevated factor VIII, n/N (%) | 26/335 (7.8) | 41/324 (12.7) | 67/659 (10.2) |
| Elevated factor XI, n/N (%) | 28/331 (8.5) | 38/316 (12.0) | 66/647 (10.2) |
| Elevated homocysteine, n/N (%) | 27/325 (8.3) | 37/313 (11.8) | 64/638 (10.0) |
| No. of abnormalities, n (%) | |||
| None | 147 (43.6) | 133 (41.0) | 280 (42.4) |
| 1 | 137 (40.6) | 133 (41.0) | 270 (40.8) |
| 2 | 44 (13.1) | 47 (14.6) | 91 (13.8) |
| 3 | 7 (2.1) | 8 (2.5) | 15 (2.3) |
| 4 | 2 (0.6) | 3 (0.9) | 5 (0.8) |