Table 2

Comorbidities associated with C. difficile colitis

	All patients		C. difficile infection				Unadjusted association			Adjusted association*
			Absent		Present		95% CI			95% CI
	Count	Per cent	N	Per cent	N	Per cent	RR	Lower	Upper	RR	Lower	Upper
HIV	3481	0.83	3143	90.29	338	9.71	2.31	2.08	2.56	2.68	2.40	2.99
≥65 years	210,405	50.11	198,324	94.26	12,081	5.74	2.08	2.02	2.15	1.76	1.70	1.82
Bacteremia	80,305	19.13	73,192	91.14	7113	8.86	2.80	2.72	2.88	1.74	1.68	1.80
Diabetes	168,129	40.04	157,420	93.63	10,709	6.37	2.24	2.18	2.31	1.54	1.49	1.59
UTI	41,234	9.82	37,346	90.57	3888	9.43	2.54	2.45	2.63	1.44	1.38	1.49
GI bleeding	26,495	6.31	24,066	90.83	2429	9.17	2.34	2.24	2.44	1.42	1.35	1.48
Osteomyelitis	10,838	2.58	9838	90.77	1000	9.23	2.24	2.11	2.38	1.35	1.27	1.44
Laparotomy	1992	0.47	1830	91.87	162	8.13	1.92	1.65	2.22	1.33	1.14	1.55
Diverticulitis	9690	2.31	8783	90.64	907	9.36	2.27	2.13	2.41	1.32	1.23	1.41
Duodenal ulcer	4540	1.08	4135	91.08	405	8.92	2.12	1.93	2.33	1.30	1.18	1.43
HCV	9594	2.28	8942	93.20	652	6.80	1.62	1.50	1.75	1.27	1.17	1.39
Rheumatoid arthritis	3412	0.81	3157	92.53	255	7.47	1.77	1.57	1.99	1.25	1.11	1.41
Pneumonia	50,131	11.94	45,967	91.69	4164	8.31	2.24	2.17	2.32	1.25	1.20	1.29
Hispanic	57,027	13.58	55,150	13.72	1877	10.51	0.76	0.72	0.79	0.76	0.72	0.79
Black race	122,035	29.06	117,743	29.29	4292	24.04	0.75	0.73	0.78	0.75	0.73	0.78

*These variables were statistically significant in the final model and the RR is adjusted for all other variables in the final model. The full model also included: cirrhosis, colostomy, endocarditis, esophageal reflux, esophagitis, gastric ulcer, hemodialysis, hepatitis B viral infection, incident date of dialysis, incision of chest wall or pleural cavity, kidney transplant, leucopenia, pancytopenia, peritoneal dialysis, and urosepsis.
GI, gastrointestinal; HCV, hepatitis C virus; UTI, urinary tract infection.