Epilepsy is associated with higher subsequent mortality risk in patients after stroke: a population-based cohort study in Taiwan

Figures & data

Table 1 Distribution of age, sex, and comorbidities between stroke and comparison cohorts

	Total stroke N=13,603		Poststroke non-epilepsy N=11,952		Poststroke epilepsy N=1,651		Comparison cohort N=27,207
	n	%	n	%	n	%	n	%	P-value^
Age, years									0.05
40–64	4,475	32.9	3,893	32.6	582	35.3	9,278	34.1
65–74	4,064	29.9	3,612	30.2	452	27.4	8,033	29.5
≥75	5,064	37.2	4,447	37.2	617	37.4	9,896	36.4
Mean (SD)^§	69.7	11.8	69.8	11.7	69.0	12.6	69.3	11.5	<0.001
Sex									0.86
Female	12,052	44.3	5,353	44.8	685	41.5	6,038	44.4
Male	15,155	55.7	6,599	55.2	966	58.5	7,565	55.6
Comorbidity
Alcohol-related illness	633	4.65	548	4.59	85	5.15	1,351	4.97	0.17
Anxiety disorders	4,146	30.5	3,695	30.9	451	27.3	8,250	30.3	0.75
Mental disorders	7,663	56.3	6,708	56.1	955	57.8	15,152	55.7	0.22
Insomnia	9,741	71.6	8,448	70.7	1,293	78.3	19,456	71.5	0.84
Depression	1,373	10.1	1,186	9.92	187	11.4	2,797	10.3	0.56
Head injury	483	3.55	376	3.15	107	6.48	1,228	4.51	0.001
COPD	4,081	30.0	3,448	28.9	633	38.3	7,998	29.4	0.21
Coronary artery disease	6,441	47.4	5,719	47.9	722	43.7	12,632	46.4	0.08
Diabetes	3,545	26.1	3,127	26.2	418	25.3	6,875	25.3	0.08
Hypertension	11,953	87.9	10,483	87.7	1470	89.0	23,845	87.6	0.51
Hyperlipidemia	6,024	44.3	5,413	45.3	611	37.0	11,902	43.8	0.30
Asthma	1,994	14.7	1,712	14.3	282	17.1	4,098	15.1	0.28
Cancer (including brain tumor)	775	5.70	682	5.71	93	5.63	1,589	5.84	0.56

Notes: Chi-square test; ^§t-test; ^total stroke vs comparison cohort.

Figure 1 Comparison of cumulative incidence of mortality among the patients with poststroke epilepsy, patients with stroke without epilepsy, and comparisons from normal population.

Table 2 Incidence and HR for mortality and associated risk factors

	Event (N)	Person-years	Rate	Crude HR (95% CI)	Adjusted HR (95% CI)^*
Stroke
Comparison cohort	6,120	156,160	39.2	1.00	1.00
Poststroke non-epilepsy	4,199	58,806	71.4	1.82 (1.75, 1.89)	1.90 (1.83, 1.98)
Poststroke epilepsy	965	6,722	143.6	3.65 (3.41, 3.91)	4.18 (3.91, 4.48)
Total stroke	5,164	65,528	78.8	2.01 (1.93, 2.08)	2.12 (2.04, 2.20)
Age, year
40–64	1,534	84,946	18.1	1.00	1.00
65–74	3,065	69,777	43.9	2.44 (2.29, 3.59)	2.29 (2.15, 2.43)
≥75	6,685	66,965	99.8	5.62 (5.31, 5.94)	5.07 (4.78, 5.38)
Sex
Female	4,658	99,949	46.6	1.00	1.00
Male	6,626	121,740	54.4	1.17 (1.13, 1.21)	1.18 (1.13, 1.23)
Comorbidity
Alcohol-related illness
No	10,928	212,580	51.4	1.00	1.00
Yes	356	9,109	39.1	0.76 (0.68,0 0.84)	1.30 (1.17, 1.45)
Anxiety disorders
No	8,564	155,907	54.9	1.00	1.00
Yes	2,720	65,782	41.4	0.75 (0.72, 0.78)	0.75 (0.71, 0.79)
Mental disorders
No	4,968	99,244	50.1	1.00	1.00
Yes	6,316	122,445	51.6	1.03 (0.99, 1.07)
Insomnia
No	3,475	69,595	49.9	1.00	1.00
Yes	7,809	152,093	51.3	1.02 (0.98, 1.06)
Depression
No	10,383	199,901	51.9	1.00	1.00
Yes	901	21,788	41.4	0.79 (0.74, 0.85)	1.06 (0.99, 1.15)
Head injury
No	10,982	212,362	51.7	1.00	1.00
Yes	302	9,327	32.4	0.63 (0.56, 0.70)	0.91 (0.81, 1.02)
COPD
No	6,722	161,528	41.6	1.00	1.00
Yes	4,562	60,160	75.8	1.82 (1.75, 1.89)	1.28 (1.23, 1.33)
Coronary artery disease
No	5,303	120,403	44.0	1.00	1.00
Yes	5,981	101,285	59.1	1.34 (1.29, 1.39)	1.10 (1.05, 1.14)
Diabetes
No	7,767	167,602	46.3	1.00	1.00
Yes	3,517	54,087	65.0	1.40 (1.35, 1.46)	1.64 (1.57, 1.71)
Hypertension
No	1,068	27,513	38.8	1.00	1.00
Yes	10,216	194,176	52.6	1.35 (1.27, 1.44)	1.10 (1.03, 1.17)
Hyperlipidemia
No	7,622	126,993	60.0	1.00	1.00
Yes	3,662	94,696	38.7	0.64 (0.62, 0.67)	0.64 (0.62, 0.67)
Asthma
No	9,232	191,801	48.1	1.00	1.00
Yes	2,052	29,887	68.7	1.42 (1.36, 1.49)	1.11 (1.05, 1.16)
Cancer (including brain tumor)
No	10,333	212,448	48.6	1.00	1.00
Yes	951	9,240	102.9	2.11 (1.97, 2.25)	1.69 (1.58, 1.81)

Notes: Rate, per 1,000 person-years; *variables found to be statistically significant in the univariable model were further included in the multivariable model.

Table 3 Comparison of incidence and HR for mortality stratified by age, sex, and comorbidity between poststroke and comparison cohorts

	Comparison cohort N=27,207		Poststroke
			Total stroke (N=13,603)			Poststroke non-epilepsy (N=11,952)			Poststroke epilepsy (N=1,651)
	Event (N)	Rate	Event (N)	Rate	Adjusted HR (95% CI)^*	Event (N)	Rate	Adjusted HR (95% CI)^*	Event (N)	Rate	Adjusted HR (95% CI)^*
Age, years
40–64	717	12.2	817	31.2	2.72 (2.46, 3.01)	604	26.2	2.32 (2.08, 2.58)	213	66.4	5.38 (4.61, 6.28)
65–74	1,526	31.1	1,539	74.6	2.50 (2.33, 2.69)	1,257	66.7	2.24 (2.08, 2.41)	282	157.4	5.28 (4.65, 6.00)
≥75	3,877	80.3	2,808	150.4	1.94 (1.85, 2.04)	2,338	138.0	1.79 (1.70, 1.88)	470	272.6	3.38 (3.07, 3.72)
P for interaction					<0.001			<0.001
Sex
Female	2,515	35.8	2,143	72.2	2.12 (2.00, 2.24)	1,751	65.3	1.91 (1.80, 2.04)	392	137.8	3.99 (3.59, 4.45)
Male	3,605	42.0	3,021	84.3	2.12 (2.02, 2.23)	2,448	76.6	1.90 (1.80, 2.00)	573	147.8	4.28 (3.91, 4.67)
P for interaction					0.90			0.40
Comorbidity
None	70	29.2	49	47.7	1.88 (1.31, 2.72)	43	43.0	1.69 (1.16, 2.47)	6	226.4	16.1 (6.79, 38.4)
With any one	6,050	39.4	5,115	79.3	2.08 (2.00, 2.16)	4,156	71.9	1.86 (1.79, 1.94)	959	143.2	4.20 (3.92, 4.49)
P for interaction					0.26			0.84

Notes: Rate, per 1,000 person-years; *variables found to be statistically significant in the univariable model were further included in the multivariable model.

Table 4 Comparison of incidence and hazard ratio for mortality stratified by age, sex, and comorbidities between poststroke patients with and without epilepsy

	Poststroke non-epilepsy N=11,952	Poststroke epilepsy N=1,651
	Adjusted HR^* (95% CI)	Adjusted HR^* (95% CI)
All	1.00	2.13 (1.98, 2.29)
Age, years
40–64	1.00	2.26 (1.93, 2.66)
65–74	1.00	2.33 (2.04, 2.65)
≥75	1.00	1.86 (1.68, 2.06)
Sex
Female	1.00	2.06 (1.85, 2.31)
Male	1.00	2.16 (1.97, 2.36)
Comorbidity
None	1.00	8.57 (3.49, 21.1)
With any one	1.00	2.21 (2.06, 2.37)

Notes: *Variables found to be statistically significant in the univariable model were further included in the multivariable model.

Data availability statement

The dataset used in this study is held by the Taiwan Ministry of Health and Welfare (MOHW). Any researcher interested in accessing this dataset can submit an application form to the MOWH requesting access. Please contact the staff of MOHW (Email: [email protected]) for further assistance. Taiwan MOHW address: No. 488, Sec. 6, Zhongxiao E. Road, Nangang District, Taipei City 115, Taiwan. Phone: [phone].