Published on in Vol 6 , No 12 (2018) :December
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/11271, first published
.

1 Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, CH
2 Institute for Social Medicine, Epidemiology and Health Economics, Charité – Universitätsmedizin Berlin, Berlin, DE
3 Center for Integrative Medicine, University of Maryland School of Medicine, Baltimore, MD, US