Table 5.

Independent contribution of confounding factors in the multivariate analyses of biomedical indices

	Smoking		Age		BMI
	Prevalence*	Incidence†	Prevalence*	Incidence†	Prevalence*
	OR (95% CI)‡	OR (95% CI)‡	OR (95%Cis)‡	OR (95% CI)‡	OR (95% CI)‡
Cough #1 (7A)§	1.68 (1.12 to 2.51)
Cough #2 (7B)§	1.62 (1.03 to 2.54)
Chronic cough (7E)§	3.34 (1.49 to 7.48)		1.63 (1.08 to 2.45)
Phlegm #1 (8A)§	2.38 (1.63 to 3.47)
Phlegm #2 (8B)§	2.62 (1.60 to 4.29)		1.38 (1.05 to 1.82)
Chronic phlegm (8C)§	3.69 (1.85 to 7.35)	1.80 (1.10 to 2.96)	1.53 (1.08 to 2.16)
Breathlessness #1 (13A)§			1.59 (1.17 to 2.16)
Breathlessness #2†(13B)§			2.64 (1.36 to 5.12)
Breathlessness #3†(13C)§			5.62 (1.51 to 20.85)
CRP abnormality					1.32 (1.17 to 1.49)
SPD abnormality		4.10 (1.15 to 14.58)
Reduced FVC		3.13 (1.09 to 8.97)
Reduced FEV1		3.82 (1.38 to 10.58)
Reduced FEV1/FVC			3.92 (1.20 to 12.87)	2.11 (1.27 to 3.52)
Non-specific X-ray				1.59 (1.06 to 2.38)
Findings

Values are presented as the OR (95% CI) estimated using the logistic regression models shown in tables 3 and 4. Only statistically significant results are shown.

*An analysis of the prevalence at baseline.

†An analysis of the new incidence during the follow-up observation.

‡OR and its 95% CI of the exposed group to the control group, regarding the prevalence and incidence of biomedical indices.

§The ATS-DLD-78A questionnaire code is shown in the parentheses.

#Grade of the severity of the symptom.

ATS, American Thoracic Society; CRP, C reactive protein; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; SPD, surfactant protein D.