TABLE V.

Univariable analysis and multivariable model for physical components of general health—related QoL (SF-8 PC) in all subjects

Characteristics	Univariable associations		Final multivariable model
	Median (IQR)	P value	Unstandardized β coefficient (95% CI)	P value
Sex*		<.001
Female	52.9 (46.4–56.4)		−1.6 (−2.6 to −0.6)	.001
Male	54.5 (49.4–57.1)		Reference
Age (y)*		<.001	−0.1 (−0.1 to −0.05)	<.001
<35	55.4 (50.8–57.7)
35–45	54.2 (48.8–56.7)
≥45	52.9 (50.8–57.8)
Smoking habit*		.064
Never smoked	54.2 (48.5–56.7)
Ex-smoker	52.7 (46.4–56.5)
Current smoker	54.3 (48.7–56.9)
Body mass index (kg/m2)*		<.001
<25	54.8 (49.9–57.3)		Reference
≥25	52.9 (46.3–56.3)		−1.7 (−2.7 to −0.7)	.001
Education level*		.573
>12 y	54.2 (48.4–56.7)
≤12 y	54.1 (48.1–56.7)
Current job duration*		<.001
<5 y	54.9 (50.1–57.5)
≥5 y	53.6 (46.8–56.4)
Asthma preexisting to current job
Yes	49.8 (43.5–55.6)	.978
No	51.7 (44.4–54.2)
Asthma control		<.001
ACT score > 19	51.7 (45.8–56.2)
ACT score ≤ 19	41.2 (37.0–48.4)
Asthma*		<.001
Absent	54.4 (49.9–56.7)		Reference
Non-WRA	51.8 (46.4–56.2)		−2.3 (−3.7 to −0.9)	.002
WRA†	46.4 (38.6–51.5)		−6.9 (−8.7 to −5.3)	<.001
Depression, physician-based		.001
Absent	54.3 (48.7–56.7)
Present	51.3 (44.1–55.7)
Nonrespiratory, nondepression comorbidity		<.001
Absent	54.7 (49.9–57.2)		Reference
Present	52.8 (44.6–56.2)		−2.3 (−3.4 to −1.3)	<.001

IQR, Interquartile range.

Multivariable analysis was done on 822 subjects and incorporated well-known confounders such as age, sex, smoking habits, body mass index, academic level, and current job duration (marked with asterisks) and other covariates with a P value of <.1 in univariable analyses. Asthma control was not included because the information was available only among asthmatic subjects.

^*Well-known confounders included in the multivariable analysis.

^†WRA is defined as current asthma associated with ≥2 WRA symptoms.