Table 3.

Event Rates per 100 Person-years [Exact 95% Confidence Limits for Events]., Cause of Death According to Cumulative Hydroxyurea Exposure. (129 deaths)

Event	Never (1) 321 Person-Years	yrs<5 (2) 1152 Person Years	5≤yrs<10 (3) 593 Person-Years	10≤yrs<15 (4) 506 Person-Years	yrs≥15 (5) 337 Person-Years
Death	4.98 [2.85, 8.09]	6.77 [5.35, 8.45]	4.39 [2.87, 6.44]	1.78 [0.81, 3.38]	0 [0, 1.09]
Stroke	0 [0, 1.15]	1.04 [0.54, 1.82]	0.51 [0.10, 1.48]	0 [0, 0.73]	0.89 [0.18, 2.60]
Renal Disease	2.80 [1.28, 5.32]	2.34 [1.54, 3.41]	1.69 [0.81, 3.11]	0.99 [0.32, 2.31]	0.30 [0.01, 1.65]
Hepatic Disease	1.56 [0.52, 3.64]	0.78 [0.36, 1.48]	0.51 [0.10, 1.48]	0.20 [0.01, 1.10]	0 [0, 1.09]
Malignancy	0 [0, 1.15]	0.09 [0, 0.48]	0.34 [0.04, 1.22]	0 [0, 0.73]	0 [0, 1.09]
Sepsis/Infection	0.94 [0.19, 2.73]	2.34 [1.54, 3.41]	2.53 [1.42, 4.18]	1.98 [0.95, 3.63]	0 [0, 1.09]

The exact 95% confidence intervals for a difference between event rates (per 100 person-years) indicated a significant difference between the following cumulative HU exposure groups:

Death: 1 and 4, 1 and 5, 2 and 3, 2 and 4, 2 and 5, 3 and 4, 3 and 5, 4 and 5.

Stroke: 1 and 2, 2 and 4.

Renal Disease: 1 and 5, 2 and 4, 2 and 5, 3 and 5.

Hepatic Disease: 1 and 5, 2 and 5.

Malignancy: None.

Sepsis/Infection: 1 and 2, 2 and 5, 3 and 5, 4 and 5.