Table 8. Comparing mortality predicted by POSSUM scoring to actual mortality.

POSSUM, Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity.

POSSUM predicted mortality	Number of patients	Predicted number of deaths	Observed number of deaths	Observed:Expected
0.00-0.10	9	1	0	0
0.11-0.20	36	5	1	0.2
0.21-0.30	23	3	0	0
0.31-0.40	33	5	2	0.4
0.41-0.50	32	5	9	1.8
0.51-0.60	8	1	5	5
0.61-0.70	7	1	2	2
0.71-0.80	1	1	1	1
0.81-0.90	1	1	1	1
0.91-1.00	0	0	0	0
0.00-1.00	150	23	21	0.91