1. School of Public Health, National University of Kyiv-Mohyla Academy, Skovorody Street 2, 04655 Kiev, Ukraine
2. Department of Health Services Research, CAPHRI, Maastricht University Medical Center, Faculty of Health, Medicine and Life Sciences, P.O. Box 616, 6200 MD Maastricht, The Netherlands
3. Topinstitute Evidence-Based Education Research (TIER), Maastricht University P.O. Box 616, 6200 MD Maastricht, The Netherlands