Table 3.

Hospital Operative Volume Threshold Analysis

Operation	Average risk- adjusted mortality, %	Mortality rate, lowest volume hospitals, %	Mortality rate, highest volume hospitals	Hospital volume threshold with 95% chance of being better than average mortality*	Total no. of hospitals	Hospitals not achieving volume threshold, %	Total operative volume	No. of operations performed at hospitals below volume threshold	Operations at hospitals below volume threshold, %
Appendectomy	5.5	22.0	0.7	11	267	35	4,857	609	13
Cholecystectomy	3.9	18.2	0.7	28	298	30	17,427	1,187	7
Colectomy	17.9	36.4	11.5	38	274	76	6,727	3264	49
Inguinal and femoral hernia repair	9.8	23.3	2.9	8	222	48	1,978	490	25
Lysis of Adhesions	11.5	31.4	4.1	12	252	49	3,910	800	20
Necrotizing soft tissue infection excision	20.7	37.0	10.9	7	131	77	666	403	61
Repair of perforated peptic ulcer disease	25.5	40.8	14.4	8	156	81	871	560	64
Small bowel resection	17.3	37.6	7.2	19	256	68	4,008	1,574	39
Umbilical hernia repair	13.5	24.3	7.3	5	62	65	268	137	51
Ventral hernia repair	11.2	19.2	4.0	6	170	49	1,148	320	28

^*Hospital operative volume that optimizes probability of survival for a given operation, defined as the 2-year volume above which 95% of hospitals have better than average risk-adjusted mortality.