Prof CHOO was Chief Executive Officer at Tan Tock Seng Hospital (TTSH) and concurrently Deputy Group CEO, National Healthcare Group (Regional Health) from 2011 to 2014; and Chairman Medical Board TTSH from 2003 to 2011.

Prof Choo leads NHG in the transformation of care, as NHG evolves in its continuing journey as the Regional Health System (RHS) for central Singapore. This is to prepare the healthcare system for the ageing population by providing the right care for all segments of the population, from the well to the moderately ill to the frail elderly.

Prof Choo is well recognised as a Geriatrician with more than 20 years of experience. With his high professional standards, he was awarded TTSH Doctor of the Year in 1996.

Prof Choo was awarded the National Day Public Service Star Award in 2003 and the Public Administration Medal (Silver) in 2011. He sits on various Boards and Committees and has been invited to speak at Regional and International Conferences as well as invited Guest Speaker at other organisations.