Table 1.

Characteristics of patients receiving warfarin

Variable	Cases	Controls	Standardized differencea
	n = 10,532	n = 40,693
Age
Median (IQR)	80 (75–86)	80 (75–86)	0
Male	5,181 (49.2%)	20,018 (49.2%)	0
Income quintile
1	2,374 (22.5%)	8,294 (20.4%)	0.05
2	2,293 (21.8%)	8,744 (21.5%)	0.01
3	2,099 (19.9%)	8,080 (19.9%)	0
4	1,888 (17.9%)	7,520 (18.5%)	0.01
5	1,841 (17.5%)	7,907 (19.4%)	0.05
Missing	37 (0.4%)	148 (0.4%)	0
Residence in long-term care	1,800 (17.1%)	5,386 (13.2%)	0.11
Number of different drugs used in previous year	13 (9–17)	11 (8–15)	0.3
Comorbid conditions (previous 3 years)
Hemorrhage	395 (3.8%)	1,526 (3.8%)	0
Atrial fibrillation	7,864 (74.7%)	27,796 (68.3%)	0.14
Stroke	1,314 (12.5%)	3,964 (9.7%)	0.09
Hypertension	6,277 (59.6%)	24,072 (59.2%)	0.01
Alcohol-use disorder	455 (4.3%)	1,440 (3.5%)	0.04
Chronic kidney disease	3,362 (31.9%)	8,954 (22.0%)	0.23
Chronic liver disease	367 (3.5%)	948 (2.3%)	0.07
Other medication use within 60 days before index date
Aspirin	320 (3.0%)	1,327 (3.3%)	0.01
Other antiplatelet drugs	228 (2.2%)	841 (2.1%)	0.01
Other NSAIDs	865 (8.2%)	1,927 (4.7%)	0.15
Cyclo-oxygenase-2 inhibitor	281 (2.7%)	852 (2.1%)	0.04
Acetaminophen	2,741 (26.0%)	7,747 (19.0%)	0.17
H2-receptor antagonists	1,227 (11.7%)	3,757 (9.2%)	0.08
Other gastroprotective medications	442 (4.2%)	1,361 (3.3%)	0.05
Proton pump inhibitors	1,668 (15.8%)	5,535 (13.6%)	0.06
SSRI antidepressants	1,481 (14.1%)	3,873 (9.5%)	0.15
Corticosteroids	747 (7.1%)	1,990 (4.9%)	0.1
Other medication use within 14 days before index date
Cotrimoxazole	243 (2.3%)	244 (0.6%)	0.18
Metronidazole	67 (0.6%)	79 (0.2%)	0.08
Other oral antibiotic	1,268 (12.0%)	2,204 (5.4%)	0.27

IQR, interquartile range; NSAID, nonsteroidal anti-inflammatory drug; SSRI, selective serotonin receptor inhibitor.

^aStandardized differences <0.10 are generally not considered meaningful.