Table 4. The ratio between observed and expected 30-day and 1-year mortality for the EuroSCORE II and STS.

Statistical analysis	EuroSCORE II	STS
30-day mortality O/E ratio	1.03	1.42
P	0.37	0.56
1-year mortality O/E ratio	1.93	2.66
P	0.86	0.64

O/E ratio, observed to expected; STS, Society of Thoracic Surgeons.