Table 3. Number of persons by number of illness episodes in the end-of-follow-up questionnaire and number of event-driven surveillance reports during the entire 2007/2008 season.

		Event-driven surveillance reports of illness, No.
		0	1	2	3	4	≥5
	0	727	81	7	0	0	0
	1	425	292	28	0	0	0
End-of-follow-up questionnaire illness episodes, No.	2	225	200	105	15	3	0
	3	84	77	49	14	2	0
	4	18	31	24	13	8	2
	≥5	22	16	15	6	12	9

Wilcoxon matched pairs signed rank sum test p<0.0001.