Entire group (n=501)

COPD (n=133)

Non-COPD (n=388)

P*

Age, mean yr (SD)

61 (10.6)

63 (10.3)

61 (10.7)

0.037

Male

345 (68.9)

98 (86.7)

247  (63.7)

<0.001

Ethnicity

       

Malay

161 (32.1)

34 (30.1)

127 (32.7)

-

Chinese

240 (47.9)

56 (49.6)

184 (47.4)

-

Indian

93 (18.6)

23 (20.4)

70 (18.0)

0.464

Education level

       

No primary

80 (16.0)

16 (14.2)

64 (16.5)

-

Primary only

80 (16.0)

23 (20.4)

57 (14.7)

-

Secondary only

258 (51.5)

60 (53.1)

198 (51.0)

-

Diploma or university

80 (16.0)

14 (12.4)

66 (17.0)

-

Postgraduate

2 (0.4)

0 (0)

2 (0.5)

0.525

Occupation

       

Professional

43 (8.6)

9 (8.0)

34 (8.8)

-

Non-professional

458 (91.4)

104 (92.0)

354 (91.2)

0.790

Total family income per month**

       

<RM1000

344 (68.7)

84 (74.3)

260 (67.0)

-

RM1000-3000

148 (29.5)

29 (25.7)

119 (30.7)

-

RM3001-5000

7 (1.4)

0 (0)

7 (1.8)

-

>RM5000

2 (0.4)

0 (0)

2 (0.5)

0.256

Body Mass Index, mean (SD)

26 (4.0)

27 (16.1)

26 (4.4)

0.412

Abdominal girth in cm, mean (SD)

94 (11.8)

94 (14.8)

94 (13.0)

0.892

Cigarette smoking status

       

Ever

255 (50.9)

94 (83.2)

161 (41.5)

<0.001

Current

71 (14.2)

24 (21.2)

47 (12.1)

0.014

Passive

158 (31.5)

52 (46.0)

106 (27.3)

<0.001

Pack yrs, mean (CI)

14 (12-15)

25 (21-28)

10 (8-12)

<0.001

Occupation exposure

       

Dust

118 (23.6)

27 (23.9)

91 (23.5)

0.923

Yrs exposed to dust, mean (SD)

24 (9.9)

29 (10.3)

25 (9.5)

0.139

Chemical or gas

43 (8.6)

8 (7.1)

35 (9.0)

0.517

Yrs exposed to chemical/gas, mean (SD)

23 (10.5)

27 (12.3)

23 (10.8)

0.419


Values are numbers with percentages in parenthesis, unless otherwise stated
(SD= standard deviation; CI=95% confidence level).
*p between COPD and non-COPD subjects
** RM= Malaysian Ringgit (Malaysian currency)
Table 1: Socio-demographic characteristics of subjects.