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.