1 Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, Utrecht, the Netherlands.
2 Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, the Netherlands.
3 Department of General Practice and Elderly Care, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, the Netherlands.
4 National Institute for Public Health and the Environment, Bilthoven, the Netherlands.
5 Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, the Netherlands.
6 KLM Health Services, Schiphol, the Netherlands.
7 Imperial College, Department of Epidemiology and Public Health, London, United Kingdom.