Table 1. Patient-years at risk and incidence rates for ICH by drug exposure group.

Antithrombotic treatment	Patients, No.	Patient-years at risk	Events, No.	Crude Rate, Events per 100 Person-Years (95% CI)	Age and sex adjusted incidence rate, Events per 100 Person-Years (95% CI)
None	3108394	18498589.5	14056	0.076 (0.075–0.077)	0.093 (0.091–0.094)
Aspirin	594761	1998423.3	4701	0.24 (0.23–0.24)	0.12 (0.11–0.14)
Warfarin	151966	306658.9	1678	0.55 (0.52–0.57)	0.28 (0.24–0.31)
Aspirin plus Clopidogrel	83593	72635.1	264	0.36 (0.32–0.41)	0.20 (0.15–0.24)
Aspirin-Dipyridamole	59698	131792.9	650	0.49 (0.46–0.53)	0.30 (0.19–0.40)
Warfarin plus Aspirin	54152	35035.2	263	0.75 (0.66–0.85)	0.34 (0.26–0.43)
Clopidogrel	44771	43010.8	162	0.38 (0.32–0.44)	0.25 (0.16–0.34)
Rivaroxaban	23532	17873.3	91	0.51 (0.41–0.63)	0.26 (0.18–0.34)
Dipyridamole	22329	10868.0	49	0.45 (0.33–0.60)	0.15 (0.098–0.21)
Dabigatran	18541	16176.3	40	0.25 (0.18–0.34)	0.010 (0.057–0.13)
Ticagrelor plus Aspirin	11896	8829.8	25	0.28 (0.18–0.42)	0.20 (0.098–0.31)
Apixaban	8202	2688.0	12	0.45 (0.23–0.78)	0.17 (0.065–0.27)
Warfarin plus Aspirin and Clopidogrel	7682	2008.7	17	0.85 (0.49–1.36)	0.33 (0.073–0.60)
Dabigatran plus Aspirin	6929	2487.3	10	0.40 (0.19–0.74)	0.24 (0.028–0.45)
Rivaroxaban plus Aspirin	6740	2211.9	20	0.90 (0.55–1.40)	0.36 (0.16–0.56)
Aspirin-Dipyridamole plus Clopidogrel	5835	1072.6	14	1.31 (0.71–2.19)	0.44 (0.19–0.69)
Other antithrombotic medication	24734	9986.2	59	0.59 (0.45–0.76)	0.25 (0.18–0.32)

Patients could have multiple treatment courses with one drug or with different drugs.