Table 2. Adjusted U.S. National Estimates of Burden and Incidence of CDI, 2011.

Demographic Characteristic	Community-Associated CDI*		Health Care–Associated CDI†		All CDI
	Estimated No. of Cases	Incidence per 100,000 Persons	Estimated No. of Cases	Incidence per 100,000 Persons	Estimated No. of Cases	Incidence per 100,000 Persons
All cases	159,700 (132,900–186,000)	51.9 (43.2–60.5)	293,300 (264,200–322,500)	95.3 (85.9–104.8)	453,000 (397,100–508,500)	147.2 (129.1–165.3)
Sex
Male	64,300 (52,800–75,300)	42.5 (34.8–49.8)	132,700 (118,700–146,700)	87.7 (78.5–97.0)	197,000 (171,500–222,000)	130.2 (113.3–146.8)
Female	95,400 (80,100–110,700)	61.0 (51.2–70.8)	160,600 (145,500–175,800)	102.7 (93.1–112.5)	256,000 (225,600–286,500)	163.8 (144.3–183.3)
Age group
1–17 yr	12,500 (10,000–15,000)	17.9 (14.1–21.4)	4400 (3200–5800)	6.3 (4.6–8.3)	16,900 (13,200–20,800)	24.2 (18.7–29.7)
18–44 yr	35,600 (26,000–39,200)	28.7 (22.9–34.5)	20,800 (16,700–24,800)	18.3 (14.7–21.9)	53,400 (42,700–64,000)	47.0 (37.6–56.4)
45–64 yr	54,100 (45,600–62,600)	65.4 (55.1–75.6)	68,800 (61,000–76,600)	83.1 (73.7–92.5)	122,900 (106,600–139,200)	148.5 (128.8–168.1)
≥65 yr	60,500 (51,300–69,200)	146.2 (124.0–167.2)	193,300 (183,300–215,300)	481.5 (442.8–520.1)	259,800 (234,600–284,500)	627.7 (566.8–687.3)
Race‡
White	138,100 (118,500–157,700)	57.4 (49.2–65.5)	259,900 (230,100–273,800)	104.7 (95.6–113.8)	390,000 (348,600–431,500)	162.1 (144.8–179.3)
Nonwhite	21,600 (14,400–28,300)	32.2 (21.5–42.2)	41,400 (34,100–48,700)	61.8 (50.9–72.7)	63,000 (48,500–77,000)	94.0 (72.4–114.9)

^*Data for community-associated Clostridium difficile infection (CDI) were adjusted for age, sex, race, and a rate of use of nucleic acid amplification test (NAAT) of 52%. Ranges in parentheses are 95% confidence intervals.

^†Data for health care–associated CDI were adjusted for age, inpatient days, and a rate of use of NAAT of 52%.

^‡Race was imputed for 18.7% of the observed cases of C. difficile infection.