TABLE 1.
Characteristics of participants in the Singapore Chinese Health Study by respiratory symptom status
| No Symptoms n = 45104 | Non-Chronic Cough or Phlegm#n = 2652 | Chronic Phlegm n = 1475 | Chronic Dry Cough n = 364 | Chronic Bronchitis n = 417 | Adult- Onset Asthma§ n =1426 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. | % | No. | % | No. | % | No. | % | No. | % | No. | % | |
| Age, mean yr (SD) | ||||||||||||
| Baseline* | 55.7 (7.7) | 57.1 (7.9) | 55.8 (8.1) | 55.9 | (7.4) | 57.5 (8.2) | 57.4 (8.0) | |||||
| Sex, Male | 18319 | 41 | 1528 | 58 | 921 | 62 | 215 | 59 | 282 | 68 | 626 | 44 |
| Dialect | ||||||||||||
| Cantonese | 21659 | 48 | 1526 | 58 | 773 | 52 | 144 | 40 | 168 | 40 | 652 | 46 |
| Hokkien | 23445 | 52 | 1126 | 42 | 702 | 48 | 220 | 60 | 249 | 60 | 774 | 54 |
| Education | ||||||||||||
| ≤ grade 6 | 11989 | 27 | 519 | 20 | 244 | 17 | 85 | 23 | 87 | 21 | 386 | 27 |
| grade 7–10 | 19972 | 44 | 1290 | 49 | 702 | 48 | 169 | 46 | 214 | 51 | 651 | 46 |
| ≥ grade 11 | 13143 | 29 | 843 | 32 | 529 | 36 | 110 | 30 | 116 | 28 | 389 | 27 |
| Smoking | ||||||||||||
| never | 33335 | 74 | 1440 | 54 | 780 | 53 | 212 | 58 | 170 | 41 | 962 | 67 |
| past | 4591 | 10 | 323 | 12 | 202 | 14 | 36 | 10 | 54 | 13 | 175 | 12 |
| current | 7178 | 16 | 889 | 34 | 493 | 33 | 116 | 32 | 193 | 46 | 289 | 20 |
| Age started smoking‡ | ||||||||||||
| ≤ 14 yr | 1264 | 18 | 173 | 19 | 94 | 19 | 34 | 29 | 53 | 27 | 70 | 24 |
| 15–19 | 2598 | 36 | 343 | 39 | 214 | 43 | 42 | 36 | 68 | 35 | 105 | 36 |
| ≥ 20 yr | 3316 | 46 | 373 | 42 | 185 | 38 | 40 | 34 | 72 | 37 | 114 | 39 |
| Cigarettes smoked per day‡ | ||||||||||||
| ≤ 12 | 3105 | 43 | 308 | 35 | 163 | 33 | 36 | 31 | 55 | 28 | 120 | 42 |
| 13–22 | 2897 | 40 | 402 | 45 | 219 | 44 | 51 | 44 | 103 | 53 | 108 | 37 |
| ≥ 23 | 1176 | 16 | 179 | 20 | 111 | 23 | 29 | 25 | 35 | 18 | 61 | 21 |
| ETS | ||||||||||||
| Child < 18 yr | 31327 | 69 | 2035 | 77 | 1176 | 80 | 303 | 83 | 343 | 82 | 1050 | 74 |
| Adult ≥ 18 yr | 36476 | 81 | 2333 | 88 | 1326 | 90 | 324 | 89 | 388 | 93 | 1232 | 86 |
| Atopy† | 3493 | 8 | 337 | 13 | 232 | 16 | 63 | 17 | 63 | 15 | 260 | 18 |
Definition of abbreviation: SD = standard deviation, ETS = environmental tobacco smoke
*
Baseline questionnaire administered 1993–1998
†
Atopy as self-reported hay fever, allergic rhinitis, sinusitis or eczema.
‡
Percent of current smokers
§
878 subjects with childhood-onset asthma were not reported
#
Answered yes to at least one of the following questions: Do you usually cough when you get up in the morning? Do you usually cough at all during the rest of the day or at night? Do you usually bring up phlegm from your chest when you get up in the morning? Do you usually bring up phlegm from your chest during the rest of the day or at night?