From: Allopurinol and the risk of ventricular arrhythmias in the elderly: a study using US Medicare data
 | All new allopurinol use episodes | Allopurinol new use episodesa associated with versus without ventricular arrhythmias (VA) during the follow-up | P value | |
---|---|---|---|---|
 | VA | No VA |  | |
Total, N (episodes) | 28,755 | 2538 | 26,217 | Â |
Age, mean (SD) | 76.6 (7.4) | 77.2 (7.3) | 76.5 (7.5) | < 0.0001 |
Sex, N (%) | Â | Â | Â | < 0.0001 |
 Male | 14,074 (48.9%) | 1369 (53.9%) | 12,705 (48.5%) |  |
 Female | 14,681 (51.1%) | 1169 (46.1%) | 13,512 (51.5%) |  |
Race/Ethnicity, N (%) | Â | Â | Â | < 0.0001 |
 White | 22,693 (78.9%) | 1976 (77.9%) | 20,717 (79.0%) |  |
 Black | 3510 (12.2%) | 382 (15.1%) | 3128 (11.9%) |  |
 Hispanic | 606 (2.1%) | 49 (1.9%) | 557 (2.1%) |  |
 Asian | 1268 (4.4%) | 89 (3.5%) | 1179 (4.5%) |  |
 Native American | 97 (0.3%) | 7 (0.3%) | 90 (0.3%) |  |
 Other/unknown | 581 (2.0%) | 35 (1.4%) | 546 (2.1%) |  |
Region, N (%) | Â | Â | Â | 0.03 |
 Northeast | 4607 (16.0%) | 460 (18.1%) | 4147 (15.8%) |  |
 Midwest | 7315 (25.4%) | 626 (24.7%) | 6689 (25.5%) |  |
 South | 11,563 (40.2%) | 1003 (39.5%) | 10,560 (40.3%) |  |
 West | 5270 (18.3%) | 449 (8.5%) | 4821 (18.4%) |  |
Charlson–Romano comorbidity score | 3.65 (3.25) | 4.79 (3.40) | 3.54 (3.21) | < 0.0001 |