Table 3.

Relative risk ratio of stroke between observation periods.

Observation periods	N of stroke	Risk ratio (95% CI)	P value
−90 to −61 days prior to index	130	REF
1–30 days after index	206	1.58 (1.30, 1.93)	<0.001
31–60 days after index	172	1.32 (1.08, 1.62)	0.007
61–90 days after index	158	1.22 (0.99, 1.49)	0.06
151–180 days after index	165	1.27 (1.03, 1.56)	0.02
331–360 days after index	173	1.33 (1.07, 1.65)	0.009
−120 to −91 days prior to index	122	REF	<0.001
1–30 days after index	206	1.69 (1.38, 2.07)
−150 to −121 days prior to index	107	REF	<0.001
1–30 days after index	206	1.93 (1.55, 2.39)