Pooling birth cohorts in allergy and asthma: European Union-funded initiatives - a MeDALL, CHICOS, ENRIECO, and GA²LEN joint paper.

Long-term birth cohort studies are essential to understanding the life course and childhood predictors of allergy and the complex interplay between genes and the environment (including lifestyle and socioeconomic determinants). Over 100 cohorts focusing on asthma and allergy have been initiated in the world over the past 30 years. Since 2004, several research initiatives funded under the EU Framework Program for Research and Technological Development FP6-FP7 have attempted to identify, compare, and evaluate pooling data from existing European birth cohorts (GA(2)LEN: Global Allergy and European Network, FP6; ENRIECO: Environmental Health Risks in European Birth Cohorts, FP7; CHICOS: Developing a Child Cohort Research Strategy for Europe, FP7; MeDALL: Mechanisms of the Development of ALLergy, FP7). However, there is a general lack of knowledge about these initiatives and their potentials. The aim of this paper is to review current and past EU-funded projects in order to make a summary of their goals and achievements and to suggest future research needs of these European birth cohort networks.