Table 8. Comparison of prevalence of obesity and odds ratio for obesity in male smokers stratified by duration of smoking.

				Cochran-Mantel-Haenszel trend test		Multiple logistic regression
Smoking status	Duration(year)	n	BMI	Prevalence of obesity (%)	P value†	Odds ratio*	95% CI	P value
Current	< 10	593	22.1±3.6	16.9	0.16	0.95	0.72–1.23	0.67
	10–19	980	23.2±3.5	24.6		0.82	0.68–0.99	0.04
	20–34	1432	23.5±3.3	28.1		0.91	0.78–1.05	0.2
	35≤	1696	22.7±3.0	20.4		0.68	0.59–0.79	< 0.001
Past	< 10	383	23.2±3.0	23	0.49	0.82	0.63–1.05	0.12
	10–19	592	23.7±3.1	28.6		0.99	0.82–1.20	0.94
	20–34	868	23.7±3.1	29.3		1.07	0.90–1.26	0.44
	35≤	741	22.9±3.0	24.2		0.93	0.76–1.12	0.44

*Prevalence of obesity of never smokers was used as the reference value.

BMI, body mass index

^†Each P value was calculated by Cochran-Mantel-Haenszel trend test among groups stratified by duration of smoking in current or past smokers