1. I-Biostat, UHasselt, Hasselt, Belgium
2. Department of Statistics, Jimma University, Jimma, Ethiopia
3. I-Biostat, KU Leuven, Leuven, Belgium
4. Faculty of Science, Technology, Engineering and Mathematics, Open University, Milton Keynes, UK
5. Department of Biostatistics, Erasmus University Medical Center, Rotterdam, the Netherlands
6. Department of Epidemiology, Erasmus University Medical Center, Rotterdam, the Netherlands