Demographic and clinical characteristics
A total of 104 women and 76 men were included in this study. There was no significant gender difference in age, body mass index and marital status. Women had longer cough duration than men did (32.6 days vs. 29.3 days, P = 0.035). Previous postinfectious cough history, medication use for previous cough attack, daytime and nighttime cough symptom score, cough VAS and CQLQ total score were not significantly different between women and men. The detailed demographics and clinical characteristics between women and men were shown in Table 1.
Table 1. Characteristics of women and men with postinfectious cough
Variables
|
Overall
(n = 180)
|
Women
(n = 104)
|
Men
(n = 76)
|
P value
|
Age (years), mean ± SD
|
44.3 ± 12.6
|
45.0 ± 12.1
|
43.3 ± 13.2
|
0.385
|
Body mass index (kg/m2), mean ± SD
|
23.4 ± 3.1
|
23.1 ± 3.0
|
23.8 ± 3.2
|
0.131
|
Married, n (%)
|
157 (87.2)
|
91 (87.5)
|
66 (86.8)
|
0.896
|
Medication use for previous PIC, n (%)
|
27 (15)
|
20 (19.2)
|
7 (9.2)
|
0.063
|
Ever previously diagnosed with PIC, n (%)
|
29 (16.1)
|
17 (16.3)
|
12 (15.8)
|
0.920
|
Cough duration (days), mean ± SD
|
31.2 ± 9.0
|
32.6 ± 9.7
|
29.3 ± 7.5
|
0.035
|
Cough symptom score, median (IQR)
Daytime
Nighttime
|
2 (2, 2)
2 (1, 2)
|
2 (2, 2)
2 (1, 2)
|
2 (2, 2)
2 (1, 2)
|
0.379
0.220
|
Cough VAS, median (IQR)
|
6 (5, 7)
|
6 (5, 7)
|
6 (5, 7)
|
0.060
|
CQLQ, mean ± SD
Total
Physical complaints
Psychosocial issues
Functional abilities
Emotional well-being
Extreme physical complaints
Personal safety fears
|
64.5 ± 7.9
21.5 ± 3.0
12.8 ± 2.1
11.1 ± 2.0
7.2 ± 1.6
8.6 ± 1.5
6.9 ± 1.7
|
65.4 ± 7.4
21.8 ± 2.8
12.9 ± 2.0
11.2 ± 1.9
7.3 ± 1.6
9.0 ± 1.5
7.0 ± 1.7
|
63.3 ± 8.3
21.1 ± 3.2
12.8 ± 2.3
11.0 ± 2.2
7.0 ± 1.7
8.1 ± 1.3
6.8 ± 1.7
|
0.077
0.160
0.723
0.527
0.218
<0.001
0.562
|
Note: CQLQ, cough specific QoL questionnaire; IQR, interquartile range; PIC, postinfectious cough; VAS, visual analogue scale.
Gender difference in QoL
A higher mean score of extreme physical complaints was reported in women (9.0 vs. 8.1, P < 0.001). The difference between women and men was not significant in the score of total CQLQ and other five subscales in unadjusted analyses (Table 1). Women had a mean 2.20-point higher CQLQ total score than men (95% confidence interval (CI), 0.11 to 4.30; P = 0.039), after adjusting for age, cough duration, cough VAS, and clinical center (R2 = 0.297). Female sex was significantly associated with a 0.88-point increase in extreme physical complaints score compared to men in the adjusted analysis (95% CI, 0.47 to 1.28; P < 0.001). No significant difference between women and men was found in the other subscales analyses. Detailed differences in women versus men in the score of total CQLQ and six subscales in unadjusted and adjusted analyses were shown in Table 2.
Table 2. Gender differences in QoL in unadjusted and adjusted analyses
Variables
|
Unadjusted
|
|
Adjusted
|
Coefficient
|
95% CI
|
|
Coefficient
|
95% CI
|
Total CQLQ
|
2.10
|
−0.23
|
4.42
|
|
2.20*
|
0.11
|
4.30
|
Physical complaints
|
0.63
|
−0.25
|
1.51
|
|
0.63
|
−0.13
|
1.38
|
Functional abilities
|
0.19
|
−0.41
|
0.80
|
|
0.36
|
−0.22
|
0.95
|
Psychosocial issues
|
0.11
|
−0.51
|
0.73
|
|
0.24
|
−0.34
|
0.81
|
Emotional well-being
|
0.31
|
−0.18
|
0.80
|
|
0.38
|
−0.11
|
0.88
|
Extreme physical complaints
|
0.91*
|
0.50
|
1.33
|
|
0.88*
|
0.47
|
1.28
|
Personal safety fears
|
0.15
|
−0.36
|
0.65
|
|
−0.09
|
−0.54
|
0.37
|
Note: *P < 0.05
Gender difference in the association between cough severity and QoL
The association between cough VAS and CQLQ total score was marginally significantly different between women and men in unadjusted analysis (coefficient 1.67, 95% CI, −0.02 to 3.36; P = 0.053). After adjusting for age, cough duration, and study center, gender significantly modified the association between cough VAS and CQLQ total score (coefficient 1.80, 95% CI, 0.29 to 3.30; P = 0.020) (Table 3). An increase of 1-point in cough severity assessed by VAS was associated with a 2.55-point (95% CI, 1.16 to 3.95) increase in CQLQ total score in women versus a 1.26-point (95% CI, 0.20 to 2.31) increase in men (P = 0.020). Women had a higher mean CQLQ total score than men with a similar degree of cough severity (Fig.1).
Gender difference was significant in the association between VAS and physical complaints (coefficient 0.67, 95% CI, 0.04 to 1.30; P = 0.038), and psychosocial issues (coefficient 0.48, 95% CI, 0.03 to 0.93; P = 0.037). After adjusting for age, cough duration, and study center, gender difference was significant in the associations between VAS and physical complaints (coefficient 0.76, 95% CI, 0.21 to 1.30; P = 0.006), psychosocial issues (coefficient 0.42, 95% CI, 0.01 to 0.84; P = 0.045), and personal safety fears (coefficient 0.36, 95% CI, 0.03 to 0.69; P = 0.034) (Table 3).
Table 3. Gender differences in association between VAS and QoL
Variables
|
Women
|
Men
|
Interaction
|
P value
|
Total CQLQ
|
|
unadjusted
|
2.40 (1.04, 3.76)
|
0.73 (−0.32, 1.78)
|
1.67 (−0.02, 3.36)
|
0.053
|
adjusted
|
2.55 (1.16, 3.95)
|
1.26 (0.20, 2.31)
|
1.80 (0.29, 3.30)
|
0.020
|
Physical complaints
|
|
unadjusted
|
0.99 (0.48, 1.50)
|
0.32 (−0.07, 0.71)
|
0.67 (0.04, 1.30)
|
0.038
|
adjusted
|
1.12 (0.58, 1.66)
|
0.58 (0.21, 0.94)
|
0.76 (0.21, 1.30)
|
0.006
|
Functional abilities
|
|
unadjusted
|
0.59 (0.23, 0.96)
|
0.37 (0.11, 0.63)
|
0.23 (−0.20, 0.66)
|
0.301
|
adjusted
|
0.37 (−0.04, 0.77)
|
0.34 (0.05, 0.63)
|
0.17 (−0.26, 0.59)
|
0.445
|
Psychosocial issues
|
|
unadjusted
|
0.66 (0.29, 1.03)
|
0.18 (−0.10, 0.46)
|
0.48 (0.03, 0.93)
|
0.037
|
adjusted
|
0.73 (0.35, 1.11)
|
0.23 (−0.06, 0.52)
|
0.42 (0.01, 0.84)
|
0.045
|
Emotional well-being
|
|
unadjusted
|
−0.02 (−0.32, 0.28)
|
0.02 (−0.21, 0.25)
|
−0.04 (−0.41, 0.33)
|
0.839
|
adjusted
|
−0.12 (−0.47, 0.23)
|
0.04 (−0.21, 0.29)
|
−0.00 (−0.37, 0.36)
|
0.985
|
Extreme physical complaints
|
|
unadjusted
|
0.19 (−0.04, 0.42)
|
0.03 (−0.18, 0.24)
|
0.16 (−0.16, 0.47)
|
0.322
|
adjusted
|
0.24 (−0.01, 0.50)
|
0.14 (−0.08, 0.36)
|
0.20 (−0.10, 0.50)
|
0.185
|
Personal safety fears
|
|
unadjusted
|
0.02 (−0.28, 0.32)
|
−0.23 (−0.47, 0.01)
|
0.25 (−0.12, 0.63)
|
0.185
|
adjusted
|
0.18 (−0.14, 0.50)
|
−0.12 (−0.35, 0.11)
|
0.36 (0.03, 0.69)
|
0.034
|