1. Institute of Respiratory MedicineRoyal Prince Alfred HospitalCamperdownNSW2050
2. Allen and Hanburys Epidemiology UnitRoyal Prince Alfred HospitalCamperdownNSW2050
3. Department of Community MedicineUniversity of New South WalesPO Box 1KensingtonNSW2033
4. Department of MedicineUniversity of SydneyNSW2006