Bronchiectasis and increased risk of ischemic stroke: a nationwide population-based cohort study

Figures & data

Table 1 Demographic characteristics and comorbidity in patients with and without bronchiectasis

Variable	Bronchiectasis		P-value
	No	Yes
	N=6,475	N=1,295
Sex, n (%)			1
Female	3,550 (54.8)	710 (54.8)
Male	2,925 (45.2)	585 (45.2)
Age, mean (SD)a	62.0 (15.3)	62.0 (15.3)	1
Age stratification, n (%)			1
<50 years	1,445 (22.3)	289 (22.3)
50–64 years	2,075 (32.0)	415 (32.0)
≥65 years	2,955 (45.6)	591 (45.6)
Comorbidity, n (%)
Hypertension	2,399 (37.1)	476 (36.8)	0.842
Diabetes	1,018 (15.7)	208 (16.1)	0.759
Hyperlipidemia	986 (15.2)	171 (13.2)	0.62
CAD	849 (13.1)	217 (16.8)	0.001
CHF	181 (2.8)	103 (8.0)	<0.001
COPD	553 (8.5)	632 (48.8)	<0.001
AF	73 (1.1)	25 (1.9)	0.018
Without any comorbidity	3,151 (48.7)	374 (28.9)	<0.001

Notes: χ² test;

a Student’s two sample t-test.

Abbreviations: SD, standard deviation; CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; AF, atrial fibrillation.

Table 2 Comparison of incidence and hazard ratio of ischemic stroke stratified by sex, age, and comorbidity between patients with and without bronchiectasis

Variables	Bronchiectasis						Crude HRb (95% CI)	aHRc (95% CI)
	No			Yes
	Event	PYs	Ratea	Event	PYs	Ratea
All	163	34,958.00	4.66	58	6,312.70	9.18	1.93 (1.43–2.61)***	1.74 (1.28–2.35)***
Sex
Female	73	19,220.60	3.80	26	3,559.90	7.30	1.89 (1.21–2.96)*	1
Male	90	15,737.40	5.72	32	2,752.80	11.62	1.98 (1.32–2.97)**	1.31 (0.99–1.70)
Age stratification, years
<50	4	8,040.40	0.50	1	1,548.20	0.65	1.29 (0.14–11.57)	1
50–64	34	11,290.80	3.01	9	2,098.10	4.29	1.42 (0.68–2.96)	4.79 (1.88–12.17)**
≥65	125	15,626.80	7.99	48	2,666.40	18.0	2.18 (1.56–3.04)***	11.76 (4.76–29.07)***
Comorbidityd
No	34	17,260.50	1.97	4	1,970.30	2.03	1.02 (0.36–2.88)	1
Yes	129	17,697.50	7.29	54	4,342.40	12.43	1.66 (1.21–2.28)**	2.66 (1.85–3.84)***

Notes:

a Incidence rate per 1,000 PYs;

b relative hazard ratio;

c multivariable analysis including age, sex, and comorbidities;

d only have one of the comorbidities: hypertension, diabetes, hyperlipidemia, CAD, CHF, COPD, and AF.

* P<0.05,

** P<0.01, and

*** P<0.001.

Abbreviations: HR, hazard ratio; aHR, adjusted HR; CI, confidence interval; PYs, person-years; CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; AF, atrial fibrillation.

Table 3 Comparison of incidence and HR of ischemic stroke between patients with and without bronchiectasis by considering individual comorbidities

Variables	Bronchiectasis						Crude HRb (95% CI)	aHRc (95% CI)
	No			Yes
	Event	PYs	Ratea	Event	PYs	Ratea
Hypertension
No	63	22,409.60	2.81	18	4,179.70	4.31	1.52 (0.90–2.57)	1
Yes	100	12,548.40	7.97	40	2,133.00	18.75	2.27 (1.57–3.27)***	1.62 (1.21–2.17)**
Diabetes
No	107	29,613.70	3.61	38	5,331.50	7.12	1.94 (1.34–2.81)***	1
Yes	56	5,344.30	10.47	20	981.20	21.02	1.90 (1.14–3.17)*	1.97 (1.47–2.65)***
Hyperlipidemia
No	132	29,857.40	4.42	46	5,545.20	8.29	1.84 (1.31–2.57)***	1
Yes	31	5,100.60	6.07	12	767.50	15.63	2.55 (1.31–4.98)***	0.88 (0.62–1.62)
CAD
No	120	30,369.50	3.95	38	5,337.50	7.12	1.77 (1.23–2.56)*	1
Yes	43	4,588.50	9.37	20	975.20	22.55	2.08 (1.22–3.55)***	1.34 (0.98–1.83)
CHF
No	152	33,980.90	4.47	49	5,888.30	8.32	1.83 (1.32–2.52)***	1
Yes	11	977.10	11.25	9	424.40	21.22	1.79 (0.73–4.34)	1.17 (0.72–1.91)
COPD
No	136	31,793.20	4.27	24	3,278.70	7.31	1.68 (1.09–2.60)**	1
Yes	27	3,164.80	8.53	34	3,034.0	11.20	1.23 (0.74–2.05)	1.14 (0.81–1.59)
AF
No	158	34,589.70	4.56	52	6,202.10	8.38	1.80 (1.31–2.46)***	1
Yes	5	368.30	13.57	6	110.60	54.24	3.84 (1.17–12.62)*	1.92 (1.02–3.61)*

Notes:

a Incidence rate per 1,000 person-years;

b relative hazard ratio;

c multivariable analysis including age, sex, hypertension, diabetes, hyperlipidemia, CAD, COPD, AF, and bronchiectasis.

* P<0.05,

** P<0.01, and

*** P<0.001.

Abbreviations: HR, hazard ratio; aHR, adjusted HR; CI, confidence interval; PYs, person-years; CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; AF, atrial fibrillation.

Table 4 Cox proportional hazard regression analysis for the risk of ischemic stroke associated with the joint effect of bronchiectasis and individual comorbidity

Variables		N	Event n	aHRa (95% CI)
Bronchiectasis	Diabetes
No	No	5,457	107	1
Yes	No	1,087	38	2.00 (1.38–2.90)***
No	Yes	1,018	56	2.20 (1.59–3.05)***
Yes	Yes	208	20	4.42 (2.74–7.14)***
Bronchiectasis	AF
No	No	6,402	158	1
Yes	No	1,270	52	1.88 (1.37–2.57)***
No	Yes	73	5	1.89 (0.77–4.61)
Yes	Yes	25	6	7.02 (3.10–15.9)***
Bronchiectasis	Hypertension
No	No	4,076	63	1
Yes	No	819	18	1.61 (0.95–2.72)
No	Yes	2,399	100	1.79 (1.30–2.47)***
Yes	Yes	476	40	4.02 (2.69–6.02)***

Notes:

a Multivariable analysis including age and sex;

*** P<0.001.

Abbreviations: aHR, adjusted hazard ratio; CI, confidence interval; AF, atrial fibrillation.

Table 5 Odds ratios of ischemic stroke associated with bronchiectasis and covariates

Variable	Crude odds ratio (95% CI)	Adjusted odds ratioa (95% CI)
Bronchiectasis
No	1	1
Yes	1.82 (1.34–2.47)***	1.62 (1.19–2.22)**
Sex
Female	1	1
Male	1.51 (1.16–1.98)**	1.3 (0.99–1.71)
Age stratification, years
<50	1	1
50–64	6.08 (2.40–12.70)***	4.75 (1.86–12.09)**
≥65	17.74 (7.28–43.23)***	11.5 (4.63–28.5)***
Comorbidityb
No	1	1
Yes	4.13 (2.91–5.88)***	2.29 (1.59–3.31)***

Notes:

a Multivariable analysis including bronchiectasis, age, sex, and comorbidities;

b only have one of the comorbidities: hypertension, diabetes, hyperlipidemia, CAD, CHF, COPD, and AF.

** P<0.01 and

*** P<0.001.

Abbreviations: CI, confidence interval; CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; AF, atrial fibrillation.

Table 6 Comparison of ischemic stroke risk between bronchiectasis and comparison cohorts by annual number of emergency room visits and hospitalization due to acute respiratory infection

		Ischemic stroke	HR (95% CI)
		n/N	Crude	Adjusteda
Non-bronchiectasis		163/6,475	1 (Reference)	1 (Reference)
Bronchiectasis
<1		39/1,128	1.44 (1.01–2.04)	1.37 (0.96–1.95)
1–3		15/136	6.45 (3.80–11.0)***	4.31 (2.53–7.35)***
>3		4/31	8.13 (3.01–22.0)***	6.24 (2.30–16.89)***
	P for trend		<0.001	<0.001

Notes:

a Multivariable analysis including age, sex, and comorbidities.

*** P<0.001.

Abbreviations: HR, hazard ratio; CI, confidence interval.

Figure 1 Nelson–Aalen analysis comparing the cumulative probabilities of ischemic stroke between patients with and without bronchiectasis.