Table 1.

Gender and age distribution before and after stratified sampling.

Characteristics		Positive cases (N=8,827), n (%)	Negative cases (N=42,088), n (%)	Negative cases after sampling N=11,126), n (%)
Gender, male		5251 (59.49)	25990 (61.75)	6174 (55.49)
Age, years
	30-40	414 (4.69)	5843 (13.88)	522 (4.69)
	40-50	1746 (19.78)	17342 (41.20)	2204 (19.81)
	50-60	2104 (23.84)	10415 (24.75)	2656 (23.87)
	60-70	2462 (27.89)	5448 (12.94)	3108 (27.93)
	70-85	2088 (23.65)	2636 (6.26)	2636 (23.69)