Acknowledgments
We thank D. van der Laan and M. Pistorius, of the hospital pharmacy department of the Amsterdam Academic Medical Center, for analyzing the included blood samples and providing us the data to investigate our research question. Also, we thank the participants of the B-PROOF study for their enthusiasm and cooperation. Furthermore, we thank the dedicated team that conducted the study. Especially, A.C.Ham, A.W.Enneman, R.Dhonukshe-Rutten, P Lips and J.van Wijngaarden.