Table 1.
Outcomes during the extension study by sex and inter-donation groups
|
Men |
Women |
|||||||
|---|---|---|---|---|---|---|---|---|
| 8 weeks | 10 weeks | 12 weeks | p value* | 12 weeks | 14 weeks | 16 weeks | p value* | |
| Participants† | 3554 (33%) | 3695 (34%) | 3594 (33%) | ·· | 3369 (34%) | 3309 (33%) | 3236 (33%) | ·· |
| Follow-up time, years (median, IQR) | 1·2 (0·8–1·3) | 1·2 (0·8–1·3) | 1·1 (0·7–1·3) | ·· | 1·1 (0·6–1·3) | 1·1 (0·6–1·3) | 1·0 (0·6–1·2) | ·· |
| Whole blood donation rate (times per year) | 3·90 (3·83–3·96) | 3·44 (3·38–3·49) | 2·97 (2·93–3·02) | <0·0001 | 2·57 (2·53–2·62) | 2·29 (2·25–2·33) | 2·02 (1·99–2·06) | <0·0001 |
| Deferral for low haemoglobin‡ | 5·94% (5·56–6·33) | 4·43% (4·07–4·79) | 3·04% (2·71–3·38) | <0·0001 | 6·22% (5·70–6·74) | 5·19% (4·68–5·70) | 4·42% (3·92–4·93) | <0·0001 |
| Deferral for other reasons‡ | 3·32% (3·04–3·60) | 3·71% (3·39–4·04) | 3·76% (3·40–4·12) | 0·064 | 4·25% (3·84–4·67) | 5·18% (4·68–5·68) | 5·20% (4·66–5·75) | 0·003 |
| Fainting at donation session‡ | 0·15% (0·09–0·21) | 0·18% (0·11–0·26) | 0·17% (0·09–0·24) | 0·61 | 0·52% (0·37–0·67) | 0·45% (0·30–0·60) | 0·48% (0·30–0·66) | 0·68 |
| SF-36 physical wellbeing score | 56·5 (56·3–56·7) | 56·6 (56·4–56·7) | 56·4 (56·3–56·6) | 0·94 | 56·6 (56·4–56·8) | 56·4 (56·2–56·7) | 56·3 (56·1–56·5) | 0·11 |
| SF-36 mental wellbeing score | 54·3 (54·0–54·5) | 54·2 (54·0–54·4) | 54·1 (53·8–54·3) | 0·63 | 53·3 (53·0–53·6) | 53·2 (52·9–53·5) | 53·0 (52·7–53·2) | 0·077 |
| Haemoglobin (g/L) | 140·8 (140·3–141·2) | 142·7 (142·3–143·1) | 144·2 (143·8–144·6) | <0·0001 | 130·0 (129·6–130·4) | 130·8 (130·4–131·2) | 131·8 (131·4–132·2) | <0·0001 |
| Haemoglobin <135 g/L (men) or <125 g/L (women)§ | 22·29% (20·38–24·19) | 16·26% (14·72–17·81) | 14·01% (12·58–15·43) | <0·0001 | 21·80% (19·87–23·73) | 18·81% (17·00–20·62) | 16·81% (15·14–18·49) | <0·0001 |
| Ferritin (μg/L)¶ | 26·3 (25·5–27·2) | 30·3 (29·4–31·3) | 34·5 (33·5–35·6) | <0·0001 | 22·6 (21·8–23·4) | 25·5 (24·7–26·4) | 28·2 (27·2–29·1) | <0·0001 |
| Ferritin <15 μg/L§ | 21·19% (19·20–23·18) | 16·41% (14·75–18·08) | 11·87% (10·46–13·28) | <0·0001 | 25·00% (22·85–27·15) | 20·04% (18·07–22·01) | 18·46% (16·62–20·30) | <0·0001 |
| Serious adverse events‖ | 2·35% (1·83–2·88) | 2·75% (2·19–3·31) | 2·88% (2·30–3·45) | 0·25 | 2·73% (2·15–3·32) | 3·48% (2·82–4·15) | 3·21% (2·57–3·86) | 0·30 |
Data are mean or percentage (95% CI) unless otherwise stated. SF-36=36-item short-form health survey.
p values are for linear trend across groups, from analyses adjusted for baseline characteristics (centre, age, weight, new donor status) and value of the outcome at baseline (when available).
Additional missing data during the extension study were: <0·2% for blood donation, deferrals, or fainting; 21·0% for SF-36 Physical/Mental wellbeing scores, 25·0% for haemoglobin, 34·1% for ferritin. Higher SF-36 scores indicate better physical or mental wellbeing (0–100 scale range).
Deferral or fainting rate per donation session attended during the extension study.
Among individuals donating blood at end of the extension study.
Values are geometric means.
Percentage of participants reporting any serious adverse events during the extension study, in any of the 6-monthly questionnaires, including doctor-confirmed heart failure, heart attack, angina, stroke, or transient ischaemic attack; and hospital visit for falls or transport accidents.