1. Department of General Practice and Primary Health Care, University of Auckland, Auckland, New Zealand
2. Unitec Institute of Technology, Auckland, New Zealand
3. Department of Psychological Medicine, University of Auckland, Auckland, New Zealand
4. Interior Health Authority, British Columbia, Canada
5. Auckland City Hospital, Auckland, New Zealand
6. Christchurch PsychMed, St Albans, Christchurch, New Zealand
7. Department of Statistics, University of Auckland, Auckland, New Zealand