1. Pfizer R&D UK Ltd, Sandwich, Kent, CT13 9NJ, UK
2. Optum, Eden Prairie, MN 55344, USA
3. Author for correspondence: Tel.: ;
4. Marilou Terpenning MD, LTD, Eagle, ID 83616, USA
5. Global Medical Affairs, Pfizer Inc, Kirkland QC, H9J 2M5, Canada
6. Pfizer Inc, Collegeville, PA 19426, USA