Table 1.
Distribution of predictors at the intended visit
| Predictor | Swiss validation data |
Dutch development data |
||
|---|---|---|---|---|
| men (n = 32,484) |
women (n = 21,288) |
men (n = 112,491) |
women (n = 108,455) |
|
| Age, years | 46 ± 12 | 43 ± 13 | 49 ± 12 | 44 ± 13 |
| Seasonality, n (%) | ||||
| Winter | 6,148 (18.9) | 3,972 (18.7) | 22,789 (20.3) | 20,487 (18.9) |
| Spring | 8,384 (25.8) | 5,686 (26.7) | 29,040 (25.8) | 28,089 (25.9) |
| Summer | 8,769 (27.0) | 5,953 (28.0) | 31,315 (27.8) | 31,645 (29.2) |
| Fall | 9,183 (28.3) | 5,677 (26.7) | 29,347 (26.1) | 28,234 (26.0) |
| Previous Hb level, mmol/l | 9.5 ± 0.7 | 8.5 ± 0.6 | 9.4 ± 0.7 | 8.5 ± 0.6 |
| Median ΔHb, mmol/l (25th–75th percentile) | 0 (–0.4 to 0.4) | 0 (–0.4 to 0.4) | 0 (–0.4 to 0.4) | 0 (–0.4 to 0.4) |
| Median time since previous visit, days (25th–75th percentile) | 177 (119–315) | 204 (134–364) | 112 (77–210) | 154 (120–259) |
| Deferral at previous visit, n (%) | ||||
| Due to low Hb (based on mmol/l) | 884 (2.7) | 1,762 (8.3) | 3,607 (3.2) | 6,658 (6.1) |
| Due to other reason than low Hb | 1,189 (3.7) | 884 (4.2) | 3,675 (3.3) | 4,311 (4.0) |
| Median number of whole blood donations in the past 2 years (25th–75th percentile) | 3 (2–4) | 2 (2–3) | 4 (2–6) | 3 (2–4) |
| Hb intended visit, mmol/l | 9.5 ± 0.7 | 8.5 ± 0.6 | 9.3 ± 0.7 | 8.4 ± 0.6 |
| Median Hb deferral, based on mmol/1† (25th–75th percentile) | 1,065 (3.3) | 2,063 (9.7) | 4,568 (4.1) | 8,297 (7.7) |
†
Hb < 8.4 mmol/l (= 135 g/l) for men and < 7.8 mmol/l (= 125 g/l) for women.