1. Nivel (Netherlands Institute for Health Services Research), 3513CR Utrecht, The Netherlands
2. Department of Behavioral and Social Sciences, University of Groningen, 9712TS Groningen, The Netherlands
3. GGD GHOR Nederland (Overarching Organization of the Municipal Health Services), 3524JS Utrecht, The Netherlands
4. ARQ National Psychotrauma Centre, 1110AE Diemen, The Netherlands
5. RIVM (National Institute for Public Health and the Environment), 3720BA Utrecht, The Netherlands