. Author manuscript; available in PMC: 2013 Oct 16.

Published in final edited form as: Arch Med Res. 2012 Oct 16;43(7):563–570. doi: 10.1016/j.arcmed.2012.09.005

Table 2.

Age-specific proportions of total laboratory-confirmed A/H1N1 hospitalizations for the 2009 A/H1N1 influenza pandemic compared to the fourth wave of A/H1N1 influenza in Mexico spanning December 1, 2011–March 15, 2012 according to dates of symptom onset

	April 1, 2009–March 31, 2010		December 1, 2011–March 15, 2012
	Total	Proportion of hospitalizations (%)	Total	Proportion of hospitalizations (%)
Total	4420	100%	1115	100%	p^a
0-4	446	10.1%	149	13.4%	0.002
5–14	660	14.9%	95	8.5%	<0.0001
15–	1237	28%	277	24.8%	0.035
29
30–	1010	22.9%	223	20%	0.04
44
45–	798	18.0%	218	19.6%	0.25
59
≥60	269	6.1%	153	13.7%	<0.0001

Note: A significantly different age distribution of A/H1N1 hospitalizations during December 1, 2011–March 15, 2012 compared to that of the 2009 A/H1N1 influenza pandemic spanning April 1, 2009–March 31, 2010 was demonstrated. Wilcoxon test, p <0.0001.

Computed using the χ² test statistic for differences in time periods. Bold type denotes statistical significance.