Department of General Practice, Erasmus MC, Rotterdam, the Netherlands.
Lisa Jongbloed and Daniëlle van Twist are equal contributors
All correspondence and requests for reprints should be addressed to: Nynke Swart, Msc, PhD, Department of General Practice, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.