Table II. Cumulative Event Rates during the MSH Trial and Follow-Up by Cumulative Hydroxyurea Exposure.

(A) The first column shows death and events by total enrollment in the MSH trial, column 2 shows death and events by patients randomized to hydroxyurea (HU) during the MSH trial, and column 3 shows death and events by patients randomized to placebo (PL) during the MSH trial. The remaining columns consider the ‘a priori’ defined cumulative hydroxyurea exposure categories. (B) Event Rates per 100 Person-years (Exact 95% confidence limits for events; n per 100 person-years)

	Years on HU in MSH Trial, Follow Up, and Extension I
Event	TOTAL	HU	PL	Never	yr<5	5<=yr<10	10<=yr<15	yr>=15
	299	152	147	44	140	55	40	20
Total years from MSH enrollment to death or last live Follow-Up	2909	1536	1373	321	1152	593	506	337
Death	129	60	69	16	78	26	9	0
n / N (%)	43.1	39.5	46.9	36.4	55.7	47.3	22.5	0.0
n / 100 person-years	4.4	3.9	5.0	5.0	6.8	4.4	1.8	0.0
Stroke	18	11	7	0	12	3	0	3
n / N (%)	6.0	7.2	4.8	0.0	8.6	5.5	0.0	15.0
n / 100 person-years	0.6	0.7	0.5	0.0	1.0	0.5	0.0	0.9
Renal Disease	52	29	23	9	27	10	5	1
n / N (%)	17.4	19.1	15.6	20.5	19.3	18.2	12.5	5.0
n / 100 person-years	1.8	1.9	1.7	2.8	2.3	1.7	1.0	0.3
Hepatic Disease	18	7	11	5	9	3	1	0
n / N (%)	6.0	4.6	7.5	11.4	6.4	5.5	2.5	0.0
n / 100 person-years	0.6	0.5	0.8	1.6	0.8	0.5	0.2	0.0
Malignancy	3	2	1	0	1	2	0	0
n / N (%)	1.0	1.3	0.7	0.0	0.7	3.6	0.0	0.0
n / 100 person-years	0.1	0.1	0.1	0.0	0.1	0.3	0.0	0.0
Sepsis / Infection	55	28	27	3	27	15	10	0
n / N (%)	18.4	18.4	18.4	6.8	19.3	27.3	25.0	0.0
n / 100 person-years	1.9	1.8	2.0	0.9	2.3	2.5	2.0	0.0

Stroke: 14 patients with 18 episodes

Renal Disease: 16 patients with 52 episodes

Hepatic Disease: 7 patients with 18 episodes

Malignancy: 3 patients with 3 episodes

Sepsis/Infection: 23 patients with 55 episodes