Demographics | INTERVAL cohort | |||
---|---|---|---|---|
n (%) or mean (SD) | INTERVAL cohort | NHSBT general donor population | Randomised in INTERVAL trial | Not randomised |
All donors | 48,692 (100.0 %)a | 1,330,506 (100.0 %) | 45,235 (100.0 %)a | 3457 (100.0 %) |
Sex | ||||
Male | 24,212 (49.7 %) | 586,372 (44.1 %) | 22,456 (49.6 %) | 1756 (50.8 %) |
Female | 24,480 (50.3 %) | 744,134 (55.9 %) | 22,779 (50.4 %) | 1701 (49.2 %) |
Age at baseline (years) | 43.1 (14.3) | 42.3 (15.0) | 43.3 (14.2) | 39.9 (14.7) |
Age at baseline | ||||
17–24 | 6424 (13.2 %) | 234,367 (17.6 %) | 5679 (12.6 %) | 745 (21.6 %) |
25–34 | 10,236 (21.0 %) | 235,238 (17.7 %) | 9468 (20.9 %) | 768 (22.2 %) |
35–44 | 9095 (18.7 %) | 246,225 (18.5 %) | 8500 (18.8 %) | 595 (17.2 %) |
45–-54 | 11,158 (22.9 %) | 304,927 (22.9 %) | 10,456 (23.1 %) | 702 (20.3 %) |
55–-64 | 8822 (18.1 %) | 221,143 (16.6 %) | 8362 (18.5 %) | 460 (13.3 %) |
65+ | 2957 (6.1 %) | 88,606 (6.7 %) | 2770 (6.1 %) | 187 (5.4 %) |
Ethnicity | ||||
White | 44,192 (90.8 %) | 1,207,593 (90.8 %) | 41,259 (91.2 %) | 2933 (84.8 %) |
Asian | 1127 (2.3 %) | 31,829 (2.4 %) | 941 (2.1 %) | 186 (5.4 %) |
Black African | 118 (0.2 %) | 3852 (0.3 %) | 105 (0.2 %) | 13 (0.4 %) |
Black Caribbean | 307 (0.6 %) | 4971 (0.4 %) | 271 (0.6 %) | 36 (1.0 %) |
Black other | 31 (0.1 %) | 743 (0.1 %) | 29 (0.1 %) | 2 (0.1 %) |
Chinese | 164 (0.3 %) | 3831 (0.3 %) | 141 (0.3 %) | 23 (0.7 %) |
Mixed | 679 (1.4 %) | 14,838 (1.1 %) | 606 (1.3 %) | 73 (2.1 %) |
Other | 138 (0.3 %) | 3558 (0.3 %) | 122 (0.3 %) | 16 (0.5 %) |
Unknown | 1936 (4.0 %) | 59,291 (4.5 %) | 1761 (3.9 %) | 175 (5.1 %) |
Blood group | ||||
A RhD positive (A+) | 14,737 (30.3 %) | 397,277 (29.9 %) | 13,768 (30.4 %) | 969 (28.0 %) |
A RhD negative (A-) | 3744 (7.7 %) | 97,450 (7.3 %) | 3489 (7.7 %) | 255 (7.4 %) |
B RhD positive (B+) | 4244 (8.7 %) | 102,650 (7.7 %) | 3877 (8.6 %) | 367 (10.6 %) |
B RhD negative (B-) | 1070 (2.2 %) | 27,317 (2.1 %) | 993 (2.2 %) | 77 (2.2 %) |
O RhD positive (O+) | 17,642 (36.2 %) | 460,501 (34.6 %) | 16,398 (36.3 %) | 1244 (36.0 %) |
O RhD negative (O-) | 5542 (11.4 %) | 138,349 (10.4 %) | 5138 (11.4 %) | 404 (11.7 %) |
AB RhD positive (AB+) | 1293 (2.7 %) | 33,817 (2.5 %) | 1199 (2.7 %) | 94 (2.7 %) |
AB RhD negative (AB-) | 402 (0.8 %) | 9550 (0.7 %) | 368 (0.8 %) | 34 (1.0 %) |
Unknown | 18 (0.0 %) | 63,595 (4.8 %) | 5 (0.0 %) | 13 (0.4 %) |
Distance to nearest static donor centre (miles)b | ||||
0–4 | 30,405 (62.4 %) | 252,068 (18.9 %) | 27,971 (61.8 %) | 2434 (70.4 %) |
5–9 | 9801 (20.1 %) | 245,652 (18.5 %) | 9236 (20.4 %) | 565 (16.3 %) |
10–29 | 7203 (14.8 %) | 584,850 (44.0 %) | 6832 (15.1 %) | 371 (10.7 %) |
30–59 | 775 (1.6 %) | 220,388 (16.6 %) | 730 (1.6 %) | 45 (1.3 %) |
60+ | 98 (0.2 %) | 18,045 (1.4 %) | 93 (0.2 %) | 5 (0.1 %) |
Unknown | 410 (0.8 %) | 9503 (0.7 %) | 373 (0.8 %) | 37 (1.1 %) |
Donor status at baselinec | ||||
New | 1392 (2.9 %) | 288,653 (21.7 %) | 1147 (2.5 %) | 245 (7.1 %) |
Occasional | 7912 (16.2 %) | 226,507 (17.0 %) | 7053 (15.6 %) | 859 (24.8 %) |
More frequent | 39,388 (80.9 %) | 815,346 (61.3 %) | 37,035 (81.9 %) | 2353 (68.1 %) |
Donations (over last 2 years prior to baseline)d | ||||
All donations | 3.28 (2.00) | 2.24 (2.37) | 3.33 (2.00) | 2.61 (1.92) |
Whole-blood donations | 3.19 (1.81) | 2.08 (1.87) | 3.23 (1.80) | 2.55 (1.80) |
Other donations | 0.10 (1.05) | 0.16 (1.64) | 0.10 (1.07) | 0.06 (0.79) |
Deferrals (during the 2 years prior to baseline)e | ||||
Deferral for low haemoglobin | 3308 (6.8 %) | 63,071 (4.7 %) | 3094 (6.8 %) | 214 (6.2 %) |
Any other deferral | 14,628 (30.0 %) | 327,747 (24.6 %) | 13,632 (30.1 %) | 996 (28.8 %) |
Length of NHSBT donation history at baseline (years)f | 10.7 (8.4) | 8.58 (8.44) | 10.9 (8.4) | 8.47 (8.02) |
Venue type attended at baselineg | ||||
Static centre | 48,692 (100.0 %) | 99,724 (7.5 %) | 45,235 (100.0 %) | 3457 (100.0 %) |
Mobile | 0 (0.0 %) | 1,230,782 (92.5 %) | 0 (0.0 %) | 0 (0.0 %) |