Risk Of Urticaria In Geriatric Stroke Patients Who Received Influenza Vaccination: A Retrospective Cohort Study

Figures & data

Table 1 Characteristics Of Geriatric Stroke Patients With And Without Influenza Vaccination

	No IV (N=9890)		IV (N=9890)		P
	n	(%)	n	(%)
Sex					1.0000
Female	4221	(42.7)	4221	(42.7)
Male	5669	(57.3)	5669	(57.3)
Age, years					1.0000
65–69	2200	(22.2)	2200	(22.2)
70–74	2602	(26.3)	2602	(26.3)
75–79	2426	(24.5)	2426	(24.5)
80–84	1642	(16.6)	1642	(16.6)
≥85	1020	(10.3)	1020	(10.3)
Low income	92	(0.9)	92	(0.9)	1.0000
Medical center	3441	(34.8)	3441	(34.8)	1.0000
Subtypes of stroke					1.0000
Hemorrhage	1156	(11.7)	1156	(11.7)
Occlusion and stenosis	7046	(71.2)	7046	(71.2)
Transient ischemic attack	890	(9.0)	890	(9.0)
Late effects of stroke	791	(8.0)	791	(8.0)
Others	7	(0.1)	7	(0.1)
Stay in intensive care unit	1049	(10.6)	1049	(10.6)	1.0000
Neurosurgery	291	(2.9)	291	(2.9)	1.0000
Coexisting medical condition
Hypertension	4947	(50.0)	4947	(50.0)	1.0000
Diabetes	1820	(18.4)	1820	(18.4)	1.0000
Ischemic heart disease	609	(6.2)	609	(6.2)	1.0000
COPD	595	(6.0)	595	(6.0)	1.0000
Mental disorder	503	(5.1)	503	(5.1)	1.0000
Influenza	291	(2.9)	291	(2.9)	1.0000
Viral hepatitis	173	(1.8)	173	(1.8)	1.0000
Urinary tract infection	167	(1.7)	167	(1.7)	1.0000
Asthma	134	(1.4)	134	(1.4)	1.0000
Cancer	134	(1.4)	134	(1.4)	1.0000
Dementia	124	(1.3)	124	(1.3)	1.0000
Hyperlipidemia	120	(1.2)	120	(1.2)	1.0000
Congestive heart failure	45	(0.5)	45	(0.5)	1.0000
Pneumonia	38	(0.4)	38	(0.4)	1.0000
Allergic rhinitis	36	(0.4)	36	(0.4)	1.0000
Dialysis	8	(0.1)	8	(0.1)	1.0000
Epilepsy	3	(0.0)	3	(0.0)	1.0000
Liver cirrhosis	3	(0.0)	3	(0.0)	1.0000
Length of stay, days					1.0000
1–5	3875	(39.2)	3875	(39.2)
6–10	2966	(30.0)	2966	(30.0)
11–15	880	(8.9)	880	(8.9)
≥16	2169	(21.9)	2169	(21.9)
Mean ± SD	12.18±16.36		12.04±15.62		0.5577
Calendar year					1.0000
2000	1215	(12.3)	1215	(12.3)
2001	991	(10.0)	991	(10.0)
2002	998	(10.1)	998	(10.1)
2003	893	(9.0)	893	(9.0)
2004	1024	(10.4)	1024	(10.4)
2005	980	(9.9)	980	(9.9)
2006	1017	(10.3)	1017	(10.3)
2007	1235	(12.5)	1235	(12.5)
2008	1537	(15.5)	1537	(15.5)

Abbreviation: COPD, chronic obstructive pulmonary disease.

Table 2 Overall And Stratified Analysis For The Risk Of Urticaria Associated With Influenza Vaccination In Geriatric Stroke Patients^†

	No IV (N=9890)		IV (N=9890)			(95% CI)*
	Events	Rate, %	Events	Rate, %	RR
All	135	1.4	244	2.5	1.81	(1.47–2.23)
Sex
Female	61	1.5	100	2.4	1.64	(1.20–2.25)
Male	74	1.3	144	2.5	1.95	(1.47–2.57)
Age, years
65–69	33	1.6	55	2.5	1.57	(1.03–2.39)
70–74	36	1.4	66	2.5	1.83	(1.23–2.74)
75–79	30	1.2	63	2.6	2.10	(1.37–3.23)
80–84	20	1.2	36	2.2	1.80	(1.05–3.09)
≥85	14	1.4	24	2.4	1.71	(0.89–3.29)
Low income
No	133	1.4	240	2.5	1.80	(1.46–2.23)
Yes	2	2.2	4	4.4	2.00	(0.38–10.7)
Medical center
No	91	1.4	162	2.5	1.78	(1.38–2.29)
Yes	44	1.3	82	2.4	1.86	(1.30–2.68)
Subtypes of stroke
Hemorrhage	7	0.6	28	2.4	4.00	(1.76–9.10)
Occlusion and stenosis	96	1.4	171	2.4	1.78	(1.39–2.28)
Transient ischemic attack	20	2.3	23	2.6	1.15	(0.64–2.07)
Late effects of stroke	12	1.5	22	2.8	1.83	(0.91–3.68)
Stay in intensive care unit
No	128	1.5	208	2.4	1.63	(1.31–2.02)
Yes	7	0.7	36	3.4	5.14	(2.32–11.4)
Number of medical conditions
0	34	1.1	78	2.5	2.29	(1.54–3.42)
1	66	1.5	106	2.5	1.61	(1.18–2.18)
≥2	35	1.4	60	2.5	1.71	(1.14–2.59)
Length of stay, days
1–5	68	1.8	88	2.3	1.29	(0.95–1.77)
6–10	28	0.9	83	2.8	2.96	(1.94–4.53)
11–15	18	2.1	23	2.6	1.28	(0.70–2.35)
≥16	21	1.0	50	2.3	2.38	(1.44–3.95)
Calendar year
2000	13	1.1	36	3.0	2.77	(1.49–5.16)
2001	14	1.4	32	3.2	2.29	(1.23–4.24)
2002	16	1.6	14	1.4	0.88	(0.43–1.77)
2003	15	1.7	30	3.4	2.00	(1.09–3.68)
2004	19	1.9	34	3.3	1.79	(1.03–3.10)
2005	14	1.4	27	2.8	1.93	(1.03–3.60)
2006	21	2.1	23	2.3	1.10	(0.61–1.96)
2007	10	0.8	28	2.3	2.80	(1.37–5.73)
2008	13	0.9	20	1.3	1.54	(0.77–3.07)

Notes: *Adjusted all covariates listed in Table 1. ^†The RR of influenza vaccination associated urticaria was 1.90 (95% CI 1.54–2.35) after adjusted for all covariates listed in Table 1 plus urbanization and cardiovascular medications (as shown in Table S2).

Abbreviations: CI, confidence interval; RR, rate ratio; IV, influenza vaccination.

Table 3 Risk Of Urticaria Associated With Influenza Vaccination In Stroke Patients During Time Period Of Follow-Up

Time Period Of Follow-Up	No IV (N=9890)		IV (N=9890)		RR	(95% CI)*
	Events	%	Events	%
1 week	6	0.06	14	0.14	2.44	(0.94–6.34)
1 month	18	0.18	42	0.42	2.42	(1.40–4.21)
2 months	32	0.32	66	0.67	2.13	(1.40–3.25)
3 months	36	0.36	88	0.89	2.52	(1.71–3.71)
4 months	47	0.48	101	1.02	2.21	(1.57–3.12)
5 months	52	0.53	120	1.21	2.37	(1.71–3.27)
6 months	58	0.59	142	1.43	2.50	(1.84–3.39)
7 months	70	0.71	162	1.64	2.35	(1.78–3.11)
8 months	75	0.76	177	1.79	2.39	(1.83–3.13)
9 months	93	0.94	197	1.99	2.14	(1.67–2.73)
10 months	108	1.09	215	2.17	2.00	(1.59–2.52)
11 months	126	1.27	227	2.30	1.81	(1.46–2.24)
12 months	135	1.37	244	2.47	1.81	(1.47–2.23)

Note: *Adjusted all covariates listed in Table 1.

Abbreviations: CI, confidence interval; IV, influenza vaccination; RR, rate ratio.

Table 4 The Sensitivity Analysis For The One-Year Risk Of Urticaria Associated With Influenza Vaccination In Geriatric Stroke Patients

Exclusion Of Urticaria Cases	No IV (N=9890)		IV (N=9890)		RR*	(95% CI)
	Events	%	Events	%
First week after IV	132	1.3	234	2.3	1.77	(1.44–2.19)
First 1 month after IV	126	1.3	215	2.2	1.71	(1.38–2.13)
First 2 months after IV	115	1.2	199	2.0	1.73	(1.38–2.18)
First 3 months after IV	108	1.1	176	1.8	1.64	(1.29–2.08)

Note: *Adjusted all covariates listed in Table 1.

Abbreviations: CI, confidence interval; IV, influenza vaccination; RR, rate ratio.