1. Department of Research and Development, Netherlands Comprehensive Cancer Organisation, Utrecht, the Netherlands
2. Department of Respiratory Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands
3. Department of Anesthesiology, Pain and Palliative Care, Radboud University Medical Centre, Nijmegen, the Netherlands
4. Centre of Expertise in Palliative Care, Leiden University Medical Centre, Leiden, the Netherlands