Table 1.

Monthly All-cause Acute Gastroenteritis Hospitalization Rates and Adjusted Rate Ratios, Restricted to the Rotavirus Season: Prevaccine Period Compared With Postvaccine Period Overall and in Even and Odd Calendar Years^a

Age Group, y	Prevaccine Period		Postvaccine Period		Postvaccine Even Years		Postvaccine Odd Years
	Rateb	Range	Rateb	RRc (95% CI)	Rateb	RRc (95% CI)	Rateb	RRc (95% CI)
0–4	8.04	2.89–14.49	4.19	0.54 (.34–.85)d	3.92	0.50 (.32–.78)d	4.47	0.58 (.35–.95)d
5–19	0.79	0.43–1.84	0.79	0.84 (.68–1.06)	0.75	0.81 (.65–1.01)	0.83	0.88 (.69–1.12)
20–59	1.72	0.78–3.43	2.62	0.93 (.74–1.18)	2.55	0.94 (.75–1.18)	2.69	0.93 (.72–1.20)
≥60	10.24	3.34–24.33	15.74	0.82 (.58–1.17)	15.33	0.83 (.59–1.18)	16.16	0.81 (.55–1.19)

Abbreviations: CI, confidence interval; RR, rate ratio.

^aData from 26 US states from the Healthcare Cost and Utilization Project’s State Inpatient Databases; see Data Sources, in Methods, for the full list of states. Adjusted RRs are from negative binomial regression comparing the prevaccine period (2000–2006) with the postvaccine period (2008–2013) overall and by even and odd calendar years, controlling for time and restricted to the rotavirus season, defined as January–June.

^bUnadjusted rate per 10000 age-specific population.

^cRR for comparison with prevaccine era.

^dSignificant at the α = .05 level.