Table 1.
Baseline Patient Characteristics, Stratified by History of Stroke or Transient Ischemic Attack, by Treatment Group
| No History of Stroke or TIA | |||||
|---|---|---|---|---|---|
| Variable | Apixaban (n=1864) | Dabigatran (n=1168) | Rivaroxaban (n=4035) | Warfarin (n=9271) | P-Value |
| Follow-up(days) | 187±140 | 300±192 | 256±181 | 277±187 | <0.001 |
| Age(year) | 76.7±8.5 | 74.2±8.6 | 75.7±8.5 | 75.4±10.3 | <0.001 |
| <65 | 79(4.2%) | 73(6.3%) | 214(5.3%) | 959(10.3%) | |
| 65–74 | 716(38.4%) | 582(49.8%) | 1730(42.9%) | 3346(36.1%) | |
| ≥ 75 | 1069(57.4%) | 513(43.9%) | 2091(51.8%) | 4966(53.6%) | |
| Men | 829(44.5%) | 557(47.7%) | 1833(45.4%) | 4115(44.4%) | 0.153 |
| White | 1636(87.8%) | 1014(86.8%) | 3549(88.0%) | 7829(84.5%) | <0.001 |
| Black | 89(4.8%) | 56(4.8%) | 188(4.7%) | 746(8.0%) | <0.001 |
| Hispanic | 66(3.5%) | 43(3.7%) | 166(4.1%) | 414(4.5%) | 0.216 |
| Other races | 73(3.9%) | 55(4.7%) | 132(3.3%) | 282(3.0%) | 0.010 |
| Medicaid eligibility | 341(18.3%) | 273(23.4%) | 781(19.4%) | 2616(28.2%) | <0.001 |
| Low dose* | 446(23.9%) | 207(17.7%) | 1191(29.5%) | 0(0%) | <0.001 |
| CHA2DS2-VASc score† | 4.12±1.35 | 3.77±1.40 | 3.96±1.38 | 4.14±1.44 | <0.001 |
| HAS-BLED score‡ | 3.43±0.74 | 3.24±0.76 | 3.36±0.78 | 3.38±0.83 | <0.001 |
| Chronic Kidney Disease§ | 573(30.7%) | 267(22.9%) | 1118(27.7%) | 3645(39.3%) | <0.001 |
| Hypertension § | 1730(92.8%) | 1022(87.5%) | 3647(90.4%) | 8212(88.6%) | <0.001 |
| Acute Myocardial Infraction§ | 12, 6.8%) | 55(4.7%) | 246(6.1%) | 792(8.5%) | <0.001 |
| Diabetes § | 811(43.5%) | 472(40.4%) | 1618(40.1%) | 4289(46.3%) | <0.001 |
| Congest Heart Failure§ | 824(44.2%) | 458(39.2%) | 1694(42.0%) | 4920(53.1%) | <0.001 |
| No. of other Center for Medicare and Medicaid Service priority comorbidities‖ | 5.42±2.47 | 4.56±2.62 | 5.29±2.57 | 5.31 ±2.73 | <0.001 |
| Liver disease# | 23(1.2%) | 10(0.9%) | 54(1.3%) | 113(1.2%) | 0.627 |
| Vascular disease** | 427(22.9%) | 234(20.03%) | 902(22.4%) | 2545(27.5%) | <0.001 |
| Alcohol or drug use†† | 25(1.34%) | 15(1.28%) | 57(1.41%) | 125(1.35%) | 0.986 |
| History of bleeding‡‡ | 263(14.1%) | 139(11.9%) | 573(14.2%) | 1513(16.3%) | <0.001 |
| Use of antiplatelet agents§§ | 191(10.3%) | 92(7.9%) | 370(9.2%) | 810(8.7%) | 0.100 |
| Use of Nonsteroidal Anti-inflammatory Drug‖‖ | 216(11.6%) | 138(11.8%) | 515(12.8%) | 896(9.7%) | <0.001 |
| History of Stroke or TIA | |||||
| Variable | Apixaban (n=494) | Dabigatran (n=247) | Rivaroxaban (n=1104) | Warfarin (n=3082) | P-Value |
| Follow-up(days) | 178±139 | 271±192 | 256±178 | 267±183 | <0.001 |
| Age(year) | 80.3±8.3 | 78.3±8.4 | 78.8±8.6 | 77.9±10.0 | <0.001 |
| <65 | 13(2.6%) | 8(3.2%) | 57(5.2%) | 274(8.9%) | |
| 65–74 | 110(22.3%) | 75(30.4%) | 283(25.6%) | 785(25.5%) | |
| ≥ 75 | 371(75.1%) | 164(66.4%) | 764(69.2%) | 2023(65.6%) | |
| Men | 173(35.0%) | 108(43.7%) | 412(37.3%) | 1211(39.3%) | 0.079 |
| White | 430(00.7%) | 201(81.4%) | 904(81.9%) | 2467(80.1%) | <0.001 |
| Black | 23(4.7%) | 18(7.3%) | 90(8.2%) | 371(12.0%) | <0.001 |
| Hispanic | 16(3.2%) | 14(5.7%) | 67(6.1%) | 144(4.7%) | 0.078 |
| Other races | 17(3.4%) | 14(5.7%) | 43(3.9%) | 100(3.24%) | 0.213 |
| Medicaid eligibility | 122(24.7%) | 70(28.3%) | 301(27.3%) | 1129(36.6%) | <0.001 |
| Low dose* | 179(36.2%) | 66(26.7%) | 446(40.4%) | 0(0%) | <0.001 |
| CHA2DS2-VASc score† | 6.81±1.26 | 6.56±1.26 | 6.73±1.31 | 6.79±1.34 | 0.013 |
| HAS-BLED score‡ | 4.76±0.79 | 4.64±0.75 | 4.68±0.79 | 4.70±0.80 | 0.136 |
| Chronic Kidney Disease § | 230(46.6%) | 93(37.7%) | 444(40.2%) | 1601(52.0%) | <0.001 |
| Hypertension § | 476(93.4%) | 236(95.6%) | 1069(96.8%) | 2977(96.6%) | 0.782 |
| Acute Myocardial Infraction§ | 47(9.5%) | 24(9.7%) | 126(11.4%) | 422(13.7%) | 0.012 |
| Diabetes § | 244(49.4%) | 125(50.6%) | 558(50.5%) | 1696(55.0%) | 0.013 |
| Congestive Heart Failure § | 259(52.4%) | 135(54.7%) | 596(54.0%) | 1924(62.4%) | <0.001 |
| No. of other Center for Medicare and Medicaid Service priority comorbidities‖ | 6.62±2.45 | 6.31±2.56 | 6.80±2.53 | 6.76±2.58 | 0.017 |
| Liver disease# | 5(1.0%) | 1(0.4%) | 11(1.0%) | 35(1.1%) | 0.864 |
| Vascular disease** | 225(45.6%) | 91(36.8%) | 502(45.5%) | 1460(47.4%) | 0.013 |
| Alcohol or drug use†† | 2(0.4%) | 1(0.4 %) | 13(1.2%) | 42(1.4%) | 0.221 |
| History of bleeding‡‡ | 95(19.2%) | 48(19.4%) | 196(17.8%) | 701(22.7%) | 0.003 |
| Use of antiplatelet agents§§ | 126(25.5%) | 60(24.3%) | 270(24.5%) | 624(20.3%) | 0.003 |
| Use of Nonsteroidal Anti-inflammatory Drug‖‖ | 57(11.5%) | 29(11.7%) | 137(12.4%) | 297(9.6%) | 0.054 |
Abbreviations: TIA=Transient Ischemic Attack.
Continuous variables are expressed as mean and standard deviation (square brackets). Categorical variables are expressed as frequency and percentage (square brackets). P-value were calculated by Kruskal-Wallis test for continuous variables and Chi-square test for categorical variables.
Low-dose was defined as initiating apixaban 2.5mg, dabigatran 75mg, rivaroxaban 15mg or 10mg. Low-dose was only defined for DOAC users because warfarin dosing is based on international normalized ratio (INR) monitoring.
CHADS2-VASc score is a prediction measure of the risk of stroke in patients with atrial fibrillation. In the calculation of CHASDs-VASc score, age of 65–74 years, CHF, hypertension, diabetes mellitus, vascular disease, and sex category (i.e. female sex) are assigned one point, and age of ≥75 years, a history of stroke or TIA are assigned two points; CHASD2-VAS score is calculated as the sum of all points.
HAS-BLED score is a prediction measure of the risk of bleeding. It was calculated as the sum of the following factors: age of > 65 years, hypertension, renal disease, liver disease, using antiplatelet agents or NSAIDs, a history of stroke, major bleeding and alcohol or drug use, and labile INR. Because INR levels are not included in claims data, HAS-BLED score was calculated as the sum of all factors except for labile INR.
Center for Medicare and Medicaid Service (CMS) priority comorbidities were calculated using the CMS Chronic Condition Warehouse definitions.
Other CMS priority conditions included Alzheimer’s disease, related disorders or senile dementia, anemia, asthma, benign prostatic hyperplasia, cataract, chronic obstructive pulmonary disease, depression, ischemic heart disease, hip or pelvic fracture, glaucoma, hyperlipidemia, osteoporosis, rheumatoid arthritis or osteoarthritis, breast cancer, colorectal cancer, prostate cancer, lung cancer and endometrial cancer.
Liver disease was defined as having at least one inpatient or outpatient claim with primary or secondary ICD-9 code 571.xx in the year before index date.
Vascular disease was defined as having one inpatient or outpatient claim with primary or secondary ICD-9 codes 440.0x, 440.2x, 440.9x, 441.3x, 441.4x, 441.5x, 441.9x, 443.9x, 444.22, 444.81, 447.1x, 443.81, 250.70, 433.10, 433.11, 433.30 in the year before the index date.
Alcohol and drug use were defined as having at least one inpatient or outpatient claim with primary or secondary ICD-9 codes 303.xx, 304.xx, 305.xx in the year before the index date.
A history of bleeding was defined as having a claim with ICD-9 codes for any bleeding event in the year before the index date.
Antiplatelet drug use was defined as filling at least one prescription for aspirin, clopidogrel, prasugrel, dipyridamole, ticlopidine or ticagrelor in the six months before the index date.
Nonsteroidal Anti-inflammatory Drug use was defined as filling at least one prescription for diclofenac, ibuprofen, naproxen, ketoprofen, fenoprofen, flurbiprofen, piroxicam, meloxicam, mefenamic acid or indomethacin in the six months before the index date.