1. Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
2. NIHR School for Primary Care Research, Department of Primary Health Care, and
3. Bodleian Health Care Libraries, Knowledge Centre, Oxford, UK
4. Centre for Research in Evidence-Based Practice, Bond University, Gold Coast, Queensland, Australia
5. Department of Clinical Biochemistry, University of Oxford, Oxford, UK