Allopurinol and the risk of stroke in older adults receiving medicare

BMC Neurology

Table 2 Crude incidence rate of CVA with allopurinol exposure and allopurinol use duration

	Person-days of follow up	Stroke cases	Crude Stroke Incidence Rate per 1,000,000 person-days
Allopurinol Exposure^a
Yes	12,900,000	1,334	108
No	7,902,385	843	106
Allopurinol use duration
None	7,902,385	843	106
1 to 180 days	5,676,393	728	128
181 days to 2 year	4,876,688	476	98
> 2 years	1,721,507	130	76

^aAllopurinol exposure was defined as up to 30 days after last day of allopurinol prescription fill or refill to capture the biologic effect of allopurinol use

ISSN: 1471-2377