Papachristofi O, et al. - This study is planned to assess the relative contributions of patient risk profile, local and individual clinical practice on length of hospital stay after cardiac surgery. Authors identify patient risk profile as the primary determinant of variation in Length of stay (LOS), and as a result, current initiatives to reduce hospital stay by modifying consultant performance may have no substantial impact. Therefore, hospital stay reduction requires shifting away from a one-size-fits-all approach to cardiac surgery, and seeking alternative treatment options personalised to high-risk patients.