Biomarkers in SHARE: Documentation of Implementation, Collection, and Analysis of Dried Blood Spot (DBS) Samples 2015 – 2023

SHARE, the “Survey of Health, Ageing and Retirement in Europe”, is a large population-based panel survey among people aged 50 and over with data from 28 European countries and Israel. It investigates individual, economic, health-related, and social life-course circumstances in order to shed light on the challenges of population aging for individuals and society as a whole. Understanding aging per se, and how we age differently over the life course given our individual backgrounds, current health, and socio-economic factors, are the aims of SHARE. In order to maintain intertemporal, international and intercultural comparability, SHARE has adopted collection of objective data in the health domain. SHARE measures physical performance, such as grip strength, peak expiratory flow, walking speed, chair stand, word recall, and Euro-D depression among others in the physical, cognitive and mental health modules. In 2015, SHARE collected dried blood spot (DBS) samples as an additional objective measure of health. Eleven European countries and Israel participated in the DBS collection. The collection was harmonized in terms of designing documents, gaining consent, procuring blood-collection material, and training interviewers how to collect DBS samples while observing the national ethic and administrative regulations in all countries. Altogether, approximately 27,200 respondents consented, resulting in an overall participation rate of 67% with considerable differences between countries and interviewers. This report describes the carefully monitored processes of gaining consent for DBS collection and for the implementation, collection and evaluation of the to-date largest DBS-based study of a representative adult population in Europe. We also describe the choice of blood biomarkers, the assays employed to determine the blood biomarker concentrations in DBS collected in the home of survey respondents and the validation and adjustment of the laboratory results for the impact of sample collection in a non-medical environment. Finally, we present the data obtained for seven out of 17 blood biomarkers. The data for the remaining ten biomarkers analyzed at the Statens Serum Institut will follow in a separate release.