1. Department of Pulmonology; Franciscus Gasthuis; Rotterdam The Netherlands
2. Department of Physiotherapy; Franciscus Gasthuis; Rotterdam The Netherlands
3. Department of Internal Medicine; Franciscus Gasthuis; Rotterdam The Netherlands
4. Department of Public Health and Primary Care; Leiden University Medical Centre; Leiden The Netherlands
5. Department of Pulmonology; Leiden University Medical Centre; Leiden The Netherlands
6. Department of Research and Education; Horn The Netherlands