1. University of Ottawa, Ottawa, Ontario, Canada.
2. Chalmers Research Group, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
3. Canadian Coordinating Office for Health Technology Assessment, Ottawa, Ontario, Canada.
4. Quantitative Sciences, Family Health International, Durham, NC, USA.
5. Centre for Statistics in Medicine, Oxford, UK.
6. Rheumatology Unit, Queen Elizabeth Hospital, Adelaide, SA.