Our manuscript describing the Genes & Health study is published in the International Journal of Epidemiology (Sept 2019) https://doi.org/10.1093/ije/dyz174 , it is fully open access.
Inevitably, however, it is already slightly out of date. Current sample numbers are available on the home page of this website. Current phenotypes and phenotype counts are available on the Research page. In 2021 or so we plan to update the Cohort Profile.