Table 2.

Non-return rates according to characteristics of volunteer donors

		Non-return rates (% )(a)
Variable	n(b)	180 days	360 days	720 days	3240 days
Total	115,553	77.1	59.8	46.5	31.8
Gender
Female	45,143	78.1	60.1	47.1	33.5
Male	70,409	76.5	59.6	46.2	30.9
Skin color						(c)
Asian	652	85.0	71.4	60.1	42.1
White	87,610	77.5	60.2	46.8	32.2
Black	26,660	75.5	57.6	44.7	29.6
Age group(d)						(c)
18 and 19 years old	18,115	75.0	59.0	45.3	30.8
20 to 29 years old	43,990	78.0	61.8	48.9	33.2
30 to 39 years old	28,275	77.3	58.6	45.0	30.2
40 to 49 years old	17,634	77.3	58.2	44.7	30.9
50 to 59 years old	7088	75.7	57.1	44.9	33.7
60 to 65 years old	408	82.0	70.6	61.4	55.6
Marital status(d)						(c)
Single	54,187	78.1	61.9	49.2	36.,4
Widow	1358	74.8	55.2	42.9	33.0
Married	51,323	76.6	58.2	44.3	27.7
Divorced	5524	74.0	54.8	41.6	27.3
Others	2152	72.6	54.5	41.0	25.0
Blood type
A	43,299	77.8	60.4	47.1	32.5
B	12,909	76.8	59.0	45.7	31.8
AB	4253	74.9	57.6	44.1	31.4
O	54,549	76.7	59.3	46.1	31.0
Rh factor
Positive	100,402	77.5	60.4	47.0	32.3
Negative	14,559	74.1	55.2	41.8	27.3
Blood collection unit (d)
External collection	58,156	80.1	61.5	47.4	32.3
Small units	7311	65.5	49.6	38.6	27.9
Large units	50,086	75.3	59.3	46.7	32.1

(a) Estimates by Kaplan-Meier method

(b) Sums do not always equal to the total of 115,553 donors due to missing data

(c) Significant differences according to long-duration models

(d) At the moment of first donation