Table 3. Results of multivariable analysis of risk factors for COPD for all subjects and stratified by gender.

	All subjects		Men		Women
	OR (95% CI)	P value	OR (95% CI)	P value	OR (95% CI)	P value
Age (years)	1.01 (0.99–1.02)	0.485	1.01 (0.98–1.04)	0.559	1.00 (0.98–1.03)	0.886
Gender
Women	1 (reference)
Men	0.74 (0.44–1.26)	0.269
Unmarried
No	1 (reference)		1 (reference)
Yes	1.66 (0.93–2.95)	0.087	3.09 (1.25–7.61)	0.015
Biomass fuel for heating
No	1 (reference)		1 (reference)
Yes	1.76 (1.03–3.00)	0.038	2.15 (1.02–4.54)	0.045
Smoking
Never	1 (reference)		1 (reference)		1 (reference)
Active	1.57 (0.84–2.92)	0.156	1.53 (0.68–3.45)	0.310	1.27 (0.40–4.04)	0.692
Former	1.87 (0.97–3.60)	0.063	1.51 (0.61–3.72)	0.375	3.35 (1.22–9.22)	0.019
Ethnicity
Bantu	1 (reference)		1 (reference)
non-Bantu	1.73 (1.06–2.82)	0.030	1.94 (0.94–4.03)	0.075

Abbreviations: CI, confidence interval; OR, odds ratio.