Table 1.
Baseline characteristics of study population
|
Characteristics |
Normal |
Restrictive |
Obstructive |
Total |
|---|---|---|---|---|
| |
No. (%) |
No. (%) |
No. (%) |
No. (%) |
| 4,895 (73.5) | 871 (13.1) | 897 (13.4) | 6,663 (100.0) | |
| Age group (yr) |
|
|
|
|
| 40 ~ 49 |
1,923 (39.3) |
171 (19.6) |
86 (9.6) |
2,180 (32.7) |
| 50 ~ 59 |
1,455 (29.7) |
222 (25.5) |
175 (19.5) |
1,852 (27.8) |
| 60 ~ 70 |
1,028 (21.0) |
259 (29.7) |
309 (34.5) |
1,596 (24.0) |
| 70~ |
489 (10.0) |
219 (25.1) |
327 (36.5) |
1,035 (15.5) |
| Sex |
|
|
|
|
| Male |
1,834 (37.5) |
409 (47.0) |
628 (70.0) |
2,871 (43.1) |
| Female |
3,061 (62.5) |
462 (53.0) |
269 (30.0) |
3,792 (56.9) |
| Smoking status* |
|
|
|
|
| Never |
3,184 (65.4) |
505 (58.5) |
292 (32.7) |
3,981 (60.1) |
| Former |
854 (17.5) |
202 (23.4) |
299 (33.5) |
1,355 (20.5) |
| Current |
830 (17.1) |
156 (18.1) |
301 (33.7) |
1,287 (19.4) |
| Region of residence |
|
|
|
|
| Urban |
3,514 (71.8) |
607 (69.7) |
532 (59.3) |
4,653 (69.8) |
| Rural |
1,381 (28.2) |
264 (30.3) |
365 (40.7) |
2,010 (30.2) |
| Household income (quartile)* |
|
|
|
|
| 1st quartile |
962 (20.0) |
251 (29.6) |
347 (40.4) |
1,560 (23.9) |
| 2nd quartile |
1,187 (24.7) |
213 (25.1) |
217 (25.3) |
1,617 (24.8) |
| 3rd quartile |
1,204 (25.0) |
211 (24.9) |
152 (17.7) |
1,567 (24.0) |
| 4th quartile |
1,456 (30.3) |
174 (20.5) |
142 (16.6) |
1,772 (27.2) |
| Education* |
|
|
|
|
| ≤Elementary school |
1,663 (34.1) |
370 (42.8) |
474 (53.4) |
2,507 (37.8) |
| Middle school |
794 (16.3) |
156 (18.1) |
159 (17.9) |
1,109 (16.7) |
| High school |
1,480 (30.4) |
204 (23.6) |
155 (17.5) |
1,839 (27.8) |
| ≥College |
938 (19.2) |
134 (15.5) |
100 (11.3) |
1,172 (17.7) |
| No. of co-morbidities |
|
|
|
|
| 0 |
3,125 (63.8) |
429 (49.3) |
477 (53.2) |
4,031 (60.5) |
| 1 |
1,231 (25.2) |
291 (33.4) |
288 (32.1) |
1,810 (27.2) |
| 2 |
430 (8.8) |
118 (13.6) |
111 (12.4) |
659 (9.9) |
| ≥3 |
109 (2.2) |
33 (3.8) |
21 (2.3) |
163 (2.5) |
| No. of healthcare utilization |
|
|
|
|
| Yes |
555 (11.3) |
171 (19.6) |
244 (27.2) |
970 (14.6) |
| No |
4,340 (88.7) |
700 (80.4) |
653 (72.8) |
5,693 (85.4) |
| Self-reported physician diagnosis of asthma | ||||
| Yes |
107 (2.2%) |
34 (3.9%) |
33 (3.7%) |
174 (2.6%) |
| No |
4,788 (97.8%) |
837 (96.1%) |
864 (96.3%) |
6489 (93.4%) |
| Self-reported physician diagnosis of COPD | ||||
| Yes |
28 (0.6) |
7 (0.8) |
27 (3.0) |
62 (0.9) |
| No | 4,867 (99.4) | 864 (99.2) | 870 (97.0) | 6,601 (99.1) |
*The sums of some data do not equal the total because of missing data; COPD = chronic obstructive pulmonary disease; FEV1 = forced expiratory volume in 1 s (liter); FVC = forced vital capacity (liter).