Table 1:

Baseline characteristics of patients with nonvalvular atrial fibrillation by stroke risk and oral anticoagulant use

CharacteristicNo. (%) of patients*
Entire cohort
n = 64 093
High stroke risk
n = 36 199
Moderate stroke risk
n = 14 411
Oral anticoagulant
n = 20 180
No oral anticoagulant
n = 16 019
Oral anticoagulant
n = 6448
No oral anticoagulant
n = 7963
Age, mean ± SD, yr69.0 ± 15.976.9 ± 10.377.0 ± 12.364.9 ± 8.461.3 ± 11.0
Age group, yr
 18–6422 720 (35.4)2694 (13.3)2671 (16.7)2464 (38.2)3997 (50.2)
 65–7414 983 (23.4)3874 (19.2)2618 (16.3)3984 (61.8)3966 (49.8)
 ≥ 7526 390 (41.2)13 612 (67.4)10 730 (67.0)0 (0.0)0 (0.0)
Sex
 Female29 074 (45.4)9710 (48.1)8024 (50.1)2414 (37.4)3406 (42.8)
 Male35 019 (54.6)10 470 (51.9)7995 (49.9)4034 (62.6)4557 (57.2)
Health care zone
 Calgary21 391 (33.4)6824 (33.8)4695 (29.3)2150 (33.3)2568 (32.2)
 Central9424 (14.7)3116 (15.4)2591 (16.2)1035 (16.0)1047 (13.1)
 Edmonton21 076 (32.9)6268 (31.1)5675 (35.4)2027 (31.4)2830 (35.5)
 North6806 (10.6)1851 (9.2)1756 (11.0)682 (10.6)976 (12.3)
 South5396 (8.4)2121 (10.5)1302 (8.1)554 (8.6)542 (6.8)
Residence
 Urban54 707 (85.4)17 247 (85.5)13 648 (85.2)5356 (83.1)6754 (84.8)
 Rural9272 (14.5)2906 (14.4)2345 (14.6)1077 (16.7)1186 (14.9)
 Missing114 (0.2)27 (0.1)26 (0.2)15 (0.2)23 (0.3)
Pampalon deprivation index score
Material deprivation
 5 (most deprived)13 100 (20.4)4142 (20.5)3409 (21.3)1390 (21.6)1659 (20.8)
 413 434 (21.0)4328 (21.4)3283 (20.5)1378 (21.4)1653 (20.8)
 311 354 (17.7)3492 (17.3)2591 (16.2)1190 (18.5)1490 (18.7)
 210 054 (15.7)3094 (15.3)2368 (14.8)1031 (16.0)1305 (16.4)
 1 (least deprived)10 631 (16.6)3116 (15.4)2458 (15.3)1109 (17.2)1432 (18.0)
 Not defined5520 (8.6)2008 (10.0)1910 (11.9)350 (5.4)424 (5.3)
Social deprivation
 5 (most deprived)17 147 (26.8)5594 (27.7)4492 (28.0)1390 (21.6)1659 (20.8)
 414 473 (22.6)4740 (23.5)3582 (22.4)1378 (21.4)1653 (20.8)
 310 851 (16.9)3332 (16.5)2573 (16.1)1190 (18.5)1490 (18.7)
 27384 (11.5)2189 (10.9)1588 (9.9)1031 (16.0)1305 (16.4)
 1 (least deprived)8718 (13.6)2317 (11.5)1874 (11.7)1109 (17.2)1432 (18.0)
 Not defined5520 (8.6)2008 (10.0)1910 (11.9)350 (5.4)424 (5.3)
Location of initial atrial fibrillation diagnosis
 Outpatient52 969 (82.6)16 886 (83.7)11 460 (71.5)5979 (92.7)6786 (85.2)
 Inpatient11 124 (17.4)3294 (16.3)4559 (28.5)469 (7.3)1177 (14.8)
No. of comorbidities
 09088 (14.2)746 (3.7)616 (3.8)771 (12.0)846 (10.6)
 112 628 (19.7)2447 (12.1)1786 (11.1)2402 (37.2)2974 (37.3)
 213 407 (20.9)4600 (22.8)3333 (20.8)1819 (28.2)2132 (26.8)
 ≥ 328 970 (45.2)12 387 (61.4)10 284 (64.2)1456 (22.6)2011 (25.2)
Comorbidities
 Heart failure12 219 (19.1)6470 (32.1)4803 (30.0)526 (8.2)420 (5.3)
 Hypertension40 849 (63.7)17 453 (86.5)13 536 (84.5)4305 (66.8)5555 (69.8)
 Diabetes14 718 (23.0)7682 (38.1)6070 (37.9)415 (6.4)551 (6.9)
 Ischemic stroke or TIA11 334 (17.7)6307 (31.2)5027 (31.4)0 (0.0)0 (0.0)
 Chronic kidney disease30 843 (48.1)13 062 (64.7)10 118 (63.2)2124 (32.9)2224 (27.9)
 Pulmonary disease15 861 (24.7)6014 (29.8)5098 (31.8)1174 (18.2)1464 (18.4)
 Acute myocardial infarction4593 (7.2)1872 (9.3)1631 (10.2)341 (5.3)352 (4.4)
 Cancer5066 (7.9)1715 (8.5)1513 (9.4)376 (5.8)602 (7.6)
 Peripheral artery disease2702 (4.2)1126 (5.6)926 (5.8)146 (2.3)165 (2.1)
 Thyroid disease9667 (15.1)3672 (18.2)3075 (19.2)722 (11.2)960 (12.1)
 Cirrhosis348 (0.5)53 (0.3)117 (0.7)25 (0.4)58 (0.7)
CHADS2 score
 013 959 (21.8)0 (0.0)0 (0.0)1454 (22.5)1867 (23.4)
 115 155 (23.6)168 (0.8)162 (1.0)4994 (77.4)6096 (76.6)
 215 831 (24.7)10 024 (49.7)8304 (51.8)0 (0.0)0 (0.0)
 39381 (14.6)4932 (24.4)3745 (23.4)0 (0.0)0 (0.0)
 46044 (9.4)3259 (16.1)2300 (14.4)0 (0.0)0 (0.0)
 52888 (4.5)1403 (7.0)1179 (7.4)0 (0.0)0 (0.0)
 6835 (1.3)394 (2.0)329 (2.0)0 (0.0)0 (0.0)
CHADS2 score, median (IQR)2 (1–3)2 (2–4)2 (2–3)1 (1–1)1 (1–1)
  • Note: IQR = interquartile range, SD = standard deviation, TIA = transient ischemic attack.

  • * Except where noted otherwise.

  • Excludes patients who died within 90 days of nonvalvular atrial fibrillation diagnosis.

  • A score of 0 = low risk of stroke, a score of 1 or 0 and age 65–74 years = moderate risk of stroke, and any score above 1 = high risk of stroke.