Table 2. Association of long-term warfarin use and risk of hip, spine, and wrist fractures in propensity-score (PS) matched cohorts of older adults with atrial fibrillation.
| Warfarin use | Cases | Crude incidence rate (per 1000 person-years) | PS-matched hazard ratio (95 % CI) | Adjusted hazard ratioa (95 % CI) |
|---|---|---|---|---|
| Hip fracture | ||||
| ≥1 year of use | ||||
| No (nonuse) | 151 | 4.91 | 1.0 (referent) | 1.0 (referent) |
| Yes | 170 | 5.29 | 1.08 (0.87,1.35) | 1.05 (0.84,1.31) |
| ≥3 years of use | ||||
| No (nonuse) | 87 | 5.51 | 1.0 (referent) | 1.0 (referent) |
| Yes | 101 | 6.20 | 1.13 (0.84,1.5) | 1.15 (0.86,1.53) |
| Spine fracture | ||||
| ≥1 year of use= | ||||
| No (nonuse) | 24 | 0.77 | 1.0 (referent) | 1.0 (referent) |
| Yes | 31 | 0.95 | 1.23 (0.72,2.09) | 1.19 (0.70,2.03) |
| ≥3 years of use | ||||
| No (nonuse) | 14 | 0.86 | 1.0 (referent) | 1.0 (referent) |
| Yes | 14 | 0.84 | 0.98 (0.47,2.05) | 0.95 (0.45,2.02) |
| Wrist fracture | ||||
| ≥ 1 year of use | ||||
| No (nonuse) | 75 | 2.48 | 1.0 (referent) | 1.0 (referent) |
| Yes | 72 | 2.24 | 0.91 (0.66,1.26) | 0.88 (0.64,1.22) |
| ≥3 years of use | ||||
| No (nonuse) | 37 | 2.31 | 1.0 (referent) | 1.0 (referent) |
| Yes | 38 | 2.35 | 1.01 (0.64,1.59) | 1.02 (0.64,1.60) |
| Hip, spine, and wrist fracture | ||||
| ≥1 year of use | ||||
| No (nonuse) | 252 | 8.48 | 1.0 (referent) | 1.0 (referent) |
| Yes | 244 | 7.86 | 0.92 (0.77,1.10) | 0.90 (0.75,1.07) |
| ≥3 years of use | ||||
| No (nonuse) | 123 | 7.95 | 1.0 (referent) | 1.0 (referent) |
| Yes | 143 | 9.06 | 1.12 (0.88,1.43) | 1.09 (0.85,1.38) |
a
Additionally adjusted for the covariates used to calculate propensity score [age, sex, body mass index (BMI), history of multiple falls, deep venous thrombosis, pulmonary embolism, heart failure, neuropsychiatric impairment, hyperthyroidism, estrogen use, beta blockers, corticosteroids, diuretics, bisphosphonates, statins, smoking, and alcoholism]