How Leeds heart surgery data was analysed
5 April 2013 Last updated at 15:54 BST
Children's heart surgery is set to restart at Leeds General Infirmary, a week after it was claimed data showed higher-than-usual death rates there.
Operations are due to resume early next week after a meeting between NHS bosses and other partners on Thursday night.
Data suggested death rates there were double that of other centres, but experts have questioned their accuracy.
Professor Brian Jarman from the Doctor Foster Unit at Imperial College, London, explains how the data about Leeds General Infirmary was analysed.