Table 2

Rates of hospitalisation for acute respiratory disease, Sydney children under 18 years of age, 1994–2001, by age and study period, using Method 2 with summer baseline*

Age group	Population at risk†	Number of hospitalisations		Mean weekly rate			Annual rate attributable to influenza (95% CI)‡
		Number of hospitalisations		Rate/100 000 population‡
		Influenza predominant period	Baseline period	Influenza predominant period	Baseline period	Excess attributable to influenza
*As per previous study.²
†Australian Bureau of Statistics mid-year estimate for 1998.
‡Rates and CIs rounded to whole numbers.
<1 y	55972	3015	1059	206	61	145	489 (473 to 504)
1 to <2 y	54566	2538	1046	171	60	112	377 (363 to 391)
2 to <5 y	161989	4427	2430	102	47	55	184 (165 to 203)
5 to <10 y	268358	3197	2419	45	28	16	54 (37 to 72)
10 to <18 y	417458	2840	2651	25	20	5	18 (1 to 35)