TABLE 2.

Mortality rate, unadjusted and adjusted OR of mortality of diverticulitis patients according to hospital volume quartile

Hospital volume	Mortality rate, % (95% CI)	Unadjusted* OR (95% CI)	Adjusted† OR (95% CI)
1st quartile (lowest)	1.80 (1.74–1.86)	0.94 (0.90–0.99)	1.13 (1.05–1.21)
2nd quartile	1.90 (1.83–1.96)	1.00 (0.95–1.04)	1.12 (1.04–1.20)
3rd quartile	1.89 (1.83–1.95)	0.99 (0.95–1.04)	1.06 (0.98–1.14)
4th quartile (highest)	1.90 (1.83–1.95)	1.00	1.00

^*Unadjusted analysis does not account for the effect of clustering;

^†Adjusted for age, sex, race, comorbidity index score, health insurance, admission type, Hinchey classification, calendar year of admission, colectomy and effect of clustering