Table 1. Participant profile, by influenza case status and current vaccination status, Navarre, Spain, pooled analysis of 2011/12–2018/19 seasons (n = 10,356).

	Laboratory-confirmed cases		Negative controls		p value	Vaccinated in current season		Unvaccinated in current season		p value
	n	%	n	%	p value	n	%	n	%	p value
Total	4,941	100	5,415	100	NA	3,952	100	6,404	100	NA
Age groups (years)
9–44	1,798	36	1,279	24	< 0.001	265	7	2,812	44	< 0.001
45–64	1,328	27	1,194	22		516	13	2,006	31
65–84	1,342	27	2,076	38		2,189	55	1,229	19
≥ 85	473	10	866	16		982	25	357	6
Sex
Male	2,510	51	2,837	52	0.105	2,089	53	3,258	51	0.050
Female	2,431	49	2,578	48	0.105	1,863	47	3,146	49	0.050
Major chronic conditions
No	2,437	49	1,794	33	< 0.001	636	16	3,595	56	< 0.001
Yes	2,504	51	3,621	67	< 0.001	3,316	84	2,809	44	< 0.001
Healthcare setting
Primary care	2,872	58	1,540	28	< 0.001	693	18	3,719	58	< 0.001
Hospital	2,069	42	3,875	72	< 0.001	3,259	82	2,685	42	< 0.001
Influenza-like illness diagnosis in the immediately preceding season
No	4,806	97	5,248	97	0.288	3,887	98	6,167	96	< 0.001
Yes	135	3	167	3	0.288	65	2	237	4	< 0.001
Vaccination in the current season
No	3,500	71	2,904	54	< 0.001	NA
Yes	1,441	29	2,511	46	< 0.001	NA
Vaccination in the previous season
No	3,561	72	2,974	55	< 0.001	627	16	5,908	92	< 0.001
Yes	1,380	28	2,441	45	< 0.001	3,325	84	496	8	< 0.001
Vaccines in the five previous seasons
0	3,191	65	2,410	45	< 0.001	283	7	5,318	83	< 0.001
1–2	402	8	625	12		454	11	573	9
3–5	1,348	27	2,380	44		3,215	81	513	8
Influenza season
2011/12	351	7	235	4	< 0.001	96	2	490	8	< 0.001
2012/13	315	6	258	5		92	2	481	8
2013/14	527	11	476	9		331	8	672	10
2014/15	573	12	482	9		325	8	730	11
2015/16	734	15	703	13		457	12	980	15
2016/17	662	13	878	16		711	18	829	13
2017/18	1,044	21	1,167	22		1,029	26	1,182	18
2018/19	735	15	1,216	22		911	23	1,040	16

NA: not applicable.