Blood donation from 2006 to 2015 in Zhejiang Province, China: annual consecutive cross-sectional studies

OBJECTIVES: To describe the basic demographical characteristics of whole blood donors in Zhejiang Province, China, from 2006 to 2015 and to examine the trends in individual characteristics associated with blood donation and the relationship between weight and donation. DESIGN: Cross-sectional study comparing characteristics of blood donors and annual donations for the period 2006 to 2015. SETTING: Urban and rural communities in Zhejiang, China (11 cities, 89 districts or counties and 1379 townships). PARTICIPANTS: 3 226 571 volunteer blood donors. OUTCOME MEASURES: Volume of each whole blood donation and donation frequency. All data were collected by trained staff and entered into a standardised electronic information system. RESULTS: The number of blood donations generally trended up in Zhejiang Province from 2006 to 2015. Donors were predominately males aged 18 to 25 years, but this major donor age group shifted to the 26 to 45 year range by 2015. The rate of repeated blood donation was 30.8 per cent. The blood volume per donation concentrated in 200 mL and 400 mL categories has been gradually shifted to 300 mL and 400 mL. Approximately one-third of donors had a college education. The average weight of donors increased over time for both men and women. Both the blood volume of each donation and donation frequency were proportional to weight. CONCLUSIONS: The trend of voluntary non-remunerated blood donation in Zhejiang province is positive. However, given the expected growth in demand for whole blood, more research is needed to increase both the donor pool and the rate of repeated donation. The relationship between body weight and blood donation warrants further study because while improving nutritional status is associated with higher average donation volume and more frequent donations, overnutrition may lead to poorer quality of donated blood. Blood donation may present a unique opportunity for health education and body weight management to monitor and improve population health.