Table 4.

 Classification according to 30 days post-discharge standardised mortality ratio (SMR) compared with in-hospital SMR

Classification according to in-hospital SMR	Classification according to 30 days post-discharge SMR
	Worse than expected	Conforms to expected	Better than expected
Worse than expected	6	3	0
Conforms to expected	3	28	3
Better than expected	0	4	13

On the basis of the SMR and its 95% confidence interval, a hospital can be classified in three categories: better than expected, conforms to expected, and worse than expected. If the SMR is significantly above 100 or significantly below 100, the hospital is considered to have performed respectively worse or better than expected. If the SMR does not significantly differ from 100, the hospital’s performance is considered to have conformed to expected. Thirteen out of 60 hospitals were classified differently with the 30 days post-discharge timeframe in comparison with in-hospital mortality.