Donor characteristics and donor deferrals

Project leaders: Femke Atsma PhD, Paul van Noord MD PhD, Wim de Kort PhD

Donor characteristics and donor deferrals

Donor characteristics and health effects related to blood donation are the main issues within this research line. Furthermore, there is a strong focus on donor deferral. Donor InSight is a large study, which started in 2007. The primary aim of Donor InSight is to gain insight into donor characteristics. In total, 50,000 whole blood and plasma donors were invited to fill in an extensive questionnaire on many topics, like demography, lifestyle, health and disease, donor motivation, and donor satisfaction. Mid 2009 data collection was completed; 50,000 donors received the questionnaire of which 63% returned the questionnaire.

Furthermore, the research in this field focuses on health and disease within donors. The donor population is said to reflect a relatively healthy subset of individuals. In order to gain insight into the health status of donors, a description of the donor pool in terms of demographic characteristics and cardiovascular risk factors has been made, using Donor InSight data and data from the general population as reference. Additionally, a PhD project on donation frequency and cardiovascular disease has started at the end of 2009. First, the occurrence of cardiovascular disease will be explored by linking donation data with morbidity and mortality data from Statistics Netherlands. Second, the effect of donation frequency on cardiovascular disease will be investigated by comparing number of donations between medically deferred donors and non-medically deferred donors. Furthermore, the effect of number of donations on metabolic factors, such as blood pressure, lipid levels, and insulin sensitivity, will be investigated within active and newly registered donors.

Donor deferral

Low hemoglobin level (Hb) is an important reason for donor deferral. In the Netherlands, in total, about 10% of the donors visiting a collection center, is deferred. Within the deferred group, from 2-3 % of male donors up to 5-7 % of female donors are being deferred for low Hb. Since deferral is a proven reason of donor lapse, reducing this percentage is paramount. Hb is known to be related to several factors, including: gender, physical condition, iron status, Body Mass Index, nutrition, but also environmental conditions, such as environmental temperature and donation history. To disentangle these complex relations we recently started an extensive statistical modeling study on prognostic factors of Hb. In 2010 the first modeling results have been published. In a pilot study among donors, substantial iron depletion – measured as Zinc Protoporphyrin (ZPP) levels – was observed. ZPP is an anticipated predictor of iron depleted Hb production.

Key publications