He served as President of the British Medical Association (BMA) in 2010-2011, and as President of the World Medical Association in 2015.
Gwasanaethodd fel Llywydd Cymdeithas Feddygol Prydain (BMA) yn 2010-2011, ac fel Llywydd Cymdeithas Feddygol y Byd (World Medical Association) yn 2015.