Table 5.

Adjusted ORs of ICU/HDU admission in 2011/2012 and 2012/2013 by influenza subtype and age group

Influenza subtype	Age group	ORs	95% CI	P value
A/H1N1pdm09	0–4	2·43	0·73–8·09
	5–14	3·27	0·53–20·36
	15–44	5·72	2·11–15·52
	45–64	8·97	3·09–25·99
	65+	5·49	1·13–26·70
A/H3N2	0–4	2·16	0·81–5·80
	5–14	2·00	0·56–7·09
	15–44	1·78	0·66–4·80
	45–64	1·12	0·32–3·85
	65+	4·47	1·73–11·50
A/unknown	0–4	0·85	0·25–2·93
	5–14	0·92	0·10–8·50
	15–44	1·91	0·71–5·15
	45–64	2·93	1·05–8·15
	65+	2·72	1·01–7·38
B	0–4	0·96	0·33–2·85
	5–14	1·89	0·62–5·80
	15–44	1·00		0·03
	45–64	5·94	2·30–15·36
	65+	7·08	2·50–20·01
Season	2011/2012	1·00		0·9
	2012/2013	1·03	0·68–1·58

ICU, intensive care units; HDU, high dependency units; ORs, odds ratios; CI, confidence interval.