Table 2. Prevalence of airflow limitation in study population standardized by Mongolian population.

Characteristic	Study subject		Mongolian population (40–79 years old)				Prevalence of airflow limitation (%)
			Male		Female		Crude						Standardized
Age group	N	%	N (× 103)	%	N (× 103)	%	Male		Female		Overall		(by sex)
							N	%	N	%	N	%	%
40–49	267	35.8	178	50.6	186	47.5	6	6.3	8	4.7	14	5.2	5.5
50–59	264	35.4	106	30.1	121	31.0	15	17.2	15	8.5	30	11.4	12.6
60–69	146	19.6	46	13.1	54	13.8	12	27.9	12	11.7	24	16.4	19.1
70–79	69	9.2	22	6.3	30	7.7	8	25.0	10	27.0	18	26.1	26.2
Total	746	100.0	352	100.0	392	100.0							12.4
Sex													(by age)
Female	488	65.4	-	-	392	52.7	-	-	45	9.2	86	11.5	8.5
Male	258	34.6	352	47.3	-	-	41	15.9	-	-			13.6
							Age- and sex-standardized prevalence						10.9