Table 1. Patient characteristics between severe and non-severe hospitalized influenza patients, before and after matching on age, sex, and year of the epidemic season
|
Before matching (n=11,090)
|
After matching (n=5,476)
|
Variables
|
Cases:
Severe hospitalized influenza patients
(n=1,369)
|
Controls
Non-severe hospitalized influenza patients
(n=9,721)
|
Standardized differencea, %
|
Cases:
Severe hospitalized influenza cases
(n=1,369)
|
Matched controls:
Non-severe hospitalized influenza patients
(n=4,107)
|
Standardized differencea, %
|
Year of the epidemic cycle, n (%)
|
|
|
|
|
|
|
May 2009 to April 2010
|
302 (22.1)
|
1,395 (14.4)
|
20.03
|
302 (22.1)
|
906 (22.1)
|
0.00
|
May 2010 to April 2011
|
595 (43.5)
|
4,140 (42.6)
|
1.82
|
595 (43.5)
|
1,785 (43.5)
|
0.00
|
May 2011 to April 2012
|
472 (34.5)
|
4,186 (43.1)
|
-17.72
|
472 (34.5)
|
1,416 (34.5)
|
0.00
|
|
|
|
|
|
|
|
Demographic, n (%)
|
|
|
|
|
|
|
Ageb, years
|
|
|
|
|
|
|
Mean (SD)
|
68.4 (14.3)
|
66.3 (14.9)
|
0.98
|
68.4 (14.3)
|
68.3 (14.4)
|
0.05
|
20-39
|
48 (3.5)
|
500 (5.1)
|
-7.89
|
48 (3.5)
|
144 (3.5)
|
0.00
|
40-59
|
326 (23.8)
|
2,677 (27.5)
|
-8.48
|
326 (23.8)
|
978 (23.8)
|
0.00
|
60-69
|
270 (19.7)
|
1,979 (20.4)
|
-1.75
|
270 (19.7)
|
810 (19.7)
|
0.00
|
70-79
|
378 (27.6)
|
2,533 (26.1)
|
3.39
|
378 (27.6)
|
1,134 (27.6)
|
0.00
|
>80
|
347 (25.3)
|
2,032 (20.9)
|
10.45
|
347 (25.3)
|
1,041 (25.3)
|
0.00
|
Male
|
798 (58.3)
|
5,056 (52.0)
|
12.69
|
798 (58.3)
|
2,394 (58.3)
|
0.00
|
Socioeconomic status, monthly income in NTD
|
<=17,280
|
447 (32.7)
|
2,850 (29.3)
|
7.36
|
447 (32.7)
|
1,233 (30.0)
|
5.82
|
17,281-22,800
|
602 (44.0)
|
4,290 (44.1)
|
-0.20
|
602 (44.0)
|
1,856 (45.2)
|
-2.41
|
22,801-28,800
|
75 (5.5)
|
553 (5.7)
|
-0.87
|
75 (5.5)
|
223 (5.4)
|
0.44
|
28,801-36,300
|
81 (5.9)
|
643 (6.6)
|
-2.89
|
81 (5.9)
|
232 (5.6)
|
1.29
|
36,301-45,800
|
91 (6.6)
|
716 (7.4)
|
-3.14
|
91 (6.6)
|
286 (7.0)
|
-1.59
|
>45,800
|
73 (5.3)
|
669 (6.9)
|
-6.69
|
73 (5.3)
|
277 (6.7)
|
-5.90
|
|
|
|
|
|
|
|
Comedicationc, n (%)
|
|
|
|
|
|
|
Oseltamivir
|
67 (4.9)
|
435 (4.5)
|
1.89
|
67 (4.9)
|
202 (4.9)
|
0.00
|
Glucocorticoids
|
146 (10.7)
|
780 (8)
|
9.28
|
146 (10.7)
|
324 (7.9)
|
9.65
|
|
|
|
|
|
|
|
Comorbiditiesd, n (%)
|
|
|
|
|
|
|
Cardiovascular disease
|
466 (34.0)
|
2764 (28.4)
|
12.11
|
466 (34.0)
|
1,239 (30.2)
|
8.15
|
Ischemic heart disease
|
316 (23.1)
|
2,050 (21.1)
|
4.82
|
316 (23.1)
|
918 (22.4)
|
1.67
|
Myocardial infarction
|
96 (7.0)
|
402 (4.1)
|
12.69
|
96 (7.0)
|
164 (4.0)
|
13.19
|
Heart failure
|
204 (14.9)
|
872 (9.0)
|
18.26
|
204 (14.9)
|
397 (9.7)
|
15.88
|
Atrial fibrillation
|
98 (7.2)
|
375 (3.9)
|
14.45
|
98 (7.2)
|
181 (4.4)
|
12.00
|
Diabetes mellitus
|
584 (42.7)
|
3,352 (34.5)
|
16.9
|
584 (42.7)
|
1,407 (34.3)
|
17.33
|
Neurological disease
|
398 (29.1)
|
2,100 (21.6)
|
17.31
|
398 (29.1)
|
1,010 (24.6)
|
10.17
|
Cerebrovascular disease
|
325 (23.7)
|
1,782 (18.3)
|
13.29
|
325 (23.7)
|
852 (20.7)
|
7.22
|
Stroke
|
47 (3.4)
|
174 (1.8)
|
10.07
|
47 (3.4)
|
79 (1.9)
|
9.35
|
Dementia
|
115 (8.4)
|
540 (5.6)
|
10.99
|
115 (8.4)
|
271 (6.6)
|
6.84
|
Pulmonary disease
|
523 (38.2)
|
2,712 (27.9)
|
22.03
|
523 (38.2)
|
1,227 (29.9)
|
17.58
|
Chronic lung disease
|
337 (24.6)
|
1,764 (18.1)
|
15.91
|
337 (24.6)
|
849 (20.7)
|
9.33
|
Asthma
|
180 (13.1)
|
1,181 (12.1)
|
3.01
|
180 (13.1)
|
505 (12.3)
|
2.40
|
Other lung disease
|
236 (17.2)
|
701 (7.2)
|
30.92
|
236 (17.2)
|
316 (7.7)
|
29.08
|
Chronic kidney disease
|
209 (15.3)
|
841 (8.7)
|
20.42
|
209 (15.3)
|
360 (8.8)
|
20.07
|
Rheumatoid arthritis/collagen vascular diseases
|
55 (4)
|
417 (4.3)
|
-1.50
|
55 (4.0)
|
157 (3.8)
|
1.03
|
Malignancy
|
109 (8)
|
703 (7.2)
|
3.02
|
109 (8.0)
|
295 (7.2)
|
3.02
|
Charlson comorbidity score, mean (SD)
|
2.5 (2.1)
|
2.0 (2.0)
|
11.89
|
2.5 (2.1)
|
2.0 (2.0)
|
11.89
|
|
|
|
|
|
|
|
Annual medical cost in NTDd
|
|
|
|
|
|
|
<=24,999
|
275 (20.1)
|
2,827 (29.1)
|
-21.01
|
275 (20.1)
|
1,167 (28.4)
|
-19.52
|
25,000-50,000
|
222 (16.2)
|
2,121 (21.8)
|
-14.31
|
222 (16.2)
|
891 (21.7)
|
-14.01
|
50,001-100,000
|
295 (21.6)
|
2,006 (20.6)
|
2.45
|
295 (21.6)
|
845 (20.6)
|
2.39
|
>100,000
|
577 (42.1)
|
2,767 (28.5)
|
28.75
|
577 (42.1)
|
1,204 (29.3)
|
27.02
|
NTD, National Taiwan Dollar. One US dollar is approximately 30 New Taiwan Dollars.
aThe values of greater than 10% indicated substantial differences in patient characteristics between severe and non-severe patients.
bAge on admission.
cMeasured within 30 days before hospitalization.
dMeasured within 365 days before hospitalization.
Table 2. Association between the use of anti-hypertensive medicationsa and the occurrence of severe influenza disease
|
Cases:
Severe hospitalized influenza patients
(n=1,369)
|
Matched controls:
Non-severe hospitalized influenza patients
(n=4,107)
|
Adjusted OR (95% CI)b
|
Model 1c: any use of anti-hypertensive medication class, n (%)
|
ACEIs
|
139 (10.2)
|
362 (8.8)
|
1.15 (0.93-1.42)
|
ARBs
|
410 (29.9)
|
1,217 (29.6)
|
0.97 (0.84-1.12)
|
CCBs
|
596 (43.5)
|
1,797 (43.8)
|
0.95 (0.84-1.09)
|
|
|
|
|
Model 2d monotherapy of anti-hypertensive medication class, n (%)
|
ACEIs
|
32 (2.3)
|
67 (1.6)
|
1.47 (0.95-2.29)
|
ARBs
|
42 (3.1)
|
157 (3.8)
|
0.76 (0.53-1.10)
|
CCBs
|
121 (8.8)
|
498 (12.1)
|
0.70 (0.55-0.88)
|
No current anti-hypertensive treatmente
|
434 (31.7)
|
1,294 (31.5)
|
Ref
|
|
|
|
|
Model 3f: Combination therapy of anti-hypertensive regimen, n (%)
|
ACEIs and CCBs in combination
|
22 (1.6)
|
57 (1.4)
|
1.57 (0.91-2.70)
|
ARBs and CCBs in combination
|
156 (11.4)
|
503 (12.3)
|
1.23 (0.93-1.62)
|
CCBs
|
121 (8.8)
|
498 (12.1)
|
Ref
|
ACEIs, angiotensin converting enzyme inhibitors; ARBs, angiotensin receptor blockers; CCBs, Calcium channel blockers.
aMeasured within 30 days before hospitalization.
bMatched on age, sex, and year of the epidemic cycle and adjusted for demographics, use of oseltamivir and glucocorticosteroids within 30 days before hospitalization, individual comorbitities and Charlson comorbidity score within 365 days before hospitalization, and medical cost within 365 days before hospitalization.
cIncluding any use of ACEIs, ARBs, and CCBs and patient characteristics which served as potential confounders.
dData for other anti-hypertensive regimens (740 cases and 2,091 controls) were not presented in the table but were considered in the regression model for proper estimation of odds ratios of exposure of interest versus no current anti-hypertensive treatment.
ePatients may not use any anti-hypertensive medications or used anti-hypertensive medications equal to or less than 14 days within 30 days before hospitalization.
fData for ACEIs monotherapy (32 cases and 67 controls), ARBs monotherapy (42 cases and 157 controls), other anti-hypertensive regimens (562 cases and 1,531 controls), and no current anti-hypertensive medications (434 cases and 1,294 controls) were not presented in the table but were considered in the regression model for proper estimation of odds ratios of exposure of interest versus no current anti-hypertensive treatment.
Table 3. Association between the use of anti-hypertensive medicationsa and the occurrence of severe influenza disease, restricting to patients without cardiovascular comorbidities
|
Cases:
Severe hospitalized influenza patients
(n=903)
|
Matched controls:
Non-severe hospitalized influenza patients
(n=2,709)
|
Adjusted OR (95% CI)b
|
Model 1c: any use of anti-hypertensive medication class, n (%)
|
ACEIs
|
84 (9.3)
|
217 (8.0)
|
1.14 (0.86-1.50)
|
ARBs
|
236 (26.1)
|
721 (26.6)
|
0.94 (0.78-1.12)
|
CCBs
|
372 (41.2)
|
1,166 (43.0)
|
0.88 (0.75-1.04)
|
|
|
|
|
Model 2d monotherapy of anti-hypertensive medication class, n (%)
|
ACEIs
|
24 (2.7)
|
47 (1.7)
|
1.52 (0.91-2.54)
|
ARBs
|
31 (3.4)
|
110 (4.1)
|
0.78 (0.51-1.19)
|
CCBs
|
88 (9.7)
|
370 (13.7)
|
0.66 (0.50-0.87)
|
No current anti-hypertensive treatmente
|
328 (36.3)
|
959 (35.4)
|
Ref
|
|
|
|
|
Model 3f: Combination therapy of anti-hypertensive regimen, n (%)
|
ACEIs and CCBs in combination
|
15 (1.7)
|
34 (1.3)
|
1.76 (0.90-3.44)
|
ARBs and CCBs in combination
|
83 (9.2)
|
315 (11.6)
|
1.06 (0.75-1.50)
|
CCBs
|
88 (9.7)
|
370 (13.7)
|
Ref
|
ACEIs, angiotensin converting enzyme inhibitors; ARBs, angiotensin receptor blockers; CCBs, Calcium channel blockers.
aMeasured within 30 days before hospitalization.
bMatched on age, sex, and year of the epidemic cycle and adjusted for demographics, use of oseltamivir and glucocorticosteroids within 30 days before hospitalization, individual comorbitities and Charlson comorbidity score within 365 days before hospitalization, and medical cost within 365 days before hospitalization.
cIncluding any use of ACEs, ARBs, and CCBs and patient characteristics which served as potential confounders.
dData for other anti-hypertensive regimens (432 cases and 723 controls) were not presented in the table but were considered in the regression model for proper estimation of odds ratios of exposure of interest versus no current anti-hypertensive treatment.
ePatients may not use any anti-hypertensive medications or used anti-hypertensive medications equal to or less than 14 days within 30 days before hospitalization.
fData for ACEIs monotherapy (24 cases and 47 controls), ARBs monotherapy (31 cases and 110 controls), other anti-hypertensive regimens (334 cases and 874 controls), and no current anti-hypertensive medications (328 cases and 959 controls) were not presented in the table but were considered in the regression model for proper estimation of odds ratios of exposure of interest versus no current anti-hypertensive treatment.