Table 3.

Cryptosporidiosis incidence rates and rate ratios from negative binomial regression models, by age group and year group, excluding outbreak-associated cases, United States, 1995–2012

Age group (years)	Year group	Rate/100 000 population per year	RR (95% CI) (vs. 1995–2004)	RR (95% CI) (vs. 2005–2008)
All ages	1995–2004	0·94	1·00
	2005–2008	2·28	2·42 (1·78–3·30)	1·00
	2009–2012	2·68	2·84 (2·08–3·87)	1·17 (0·81–1·70)
0–14	1995–2004	1·74	1·00
	2005–2008	4·62	2·66 (2·11–3·35)	1·00
	2009–2012	3·54	2·04 (1·62–2·57)	0·77 (0·58–1·01)
15–44	1995–2004	1·05	1·00
	2005–2008	2·12	2·03 (1·73–2·39)	1·00
	2009–2012	2·50	2·39 (2·04–2·81)	1·18 (0·97–1·43)
45–64	1995–2004	0·57	1·00
	2005–2008	1·16	2·02 (1·65–2·46)	1·00
	2009–2012	1·87	3·26 (2·67–3·97)	1·62 (1·28–2·05)
⩾65	1995–2004	0·42	1·00
	2005–2008	1·24	2·96 (2·05–4·28)	1·00
	2009–2012	2·82	6·73 (4·67–9·70)	2·27 (1·47–3·50)

RR, Rate ratio; CI, confidence interval.