Table I.
The characteristics of the study sample (n (%) and mean ± SD).
| All (n = 616) | 16 y (n = 160) | 30–39 y (n = 233) | 60–69 y (n = 223) | P value | |
|---|---|---|---|---|---|
| Women | 359 (58) | 85 (53) | 138 (59) | 136 (61) | 0.29 |
| FEV1 % of predicted | 93 ± 15 | 96 ± 3 | 94 ± 15 | 90 ± 17 | < 0.05 |
| Skin prick test reactivity | |||||
| None | 293 (48) | 53 (33) | 72 (31) | 168 (75) | < 0.001 |
| 1 type of allergena | 132 (21) | 30 (19) | 57 (25) | 45 (20) | |
| 2 types of allergens | 124 (20) | 46 (29) | 72 (31) | 6 (3) | |
| 3 types of allergens | 51 (8) | 24 (15) | 24 (10) | 3 (1) | |
| 4 types of allergens | 15 (2) | 7 (4) | 7 (3) | 1 (0) | |
| Airway responsiveness to irritants | |||||
| None | 55 (9) | 10 (6) | 21 (9) | 24 (11) | < 0.01 |
| 1 irritant | 112 (18) | 31 (19) | 42 (18) | 39 (17) | |
| 2 irritants | 144 (23) | 38 (24) | 56 (24) | 50 (22) | |
| 3 irritants | 157 (26) | 46 (29) | 65 (28) | 46 (21) | |
| 4 irritants | 108 (18) | 27 (17) | 39 (17) | 42 (19) | |
| 5 irritants | 38 (16) | 8 (5) | 8 (3) | 22 (10) | |
| Respiratory symptom severity | |||||
| None | 57 (9) | 15 (9) | 22 (9) | 20 (9) | < 0.01 |
| Wheeze last year | 90 (15) | 27 (17) | 43 (18) | 20 (9) | |
| Nocturnal symptoms | 402 (65) | 108 (68) | 148 (64) | 146 (65) | |
| Daily symptoms | 67 (11) | 10 (6) | 20 (9) | 37 (17) | |
| Allergic rhinitis | 231 (43) | 75 (50) | 107 (53) | 49 (27) | < 0.001 |
| Asthma medication | |||||
| None | 324 (54) | 65 (42) | 119 (52) | 140 (65) | < 0.001 |
| Bronchodilators | 87 (15) | 36 (23) | 32 (14) | 19 (9) | |
| Inhaled corticosteroids | 162 (27) | 52 (34) | 61 (27) | 49 (23) | |
| Oral corticosteroids | 24 (4) | 2 (1) | 15 (7) | 7 (3) | |
| Smoking history | |||||
| Non-smokers | 334 (54) | 147 (92) | 70 (30) | 117 (52) | < 0.001 |
| Ex-smokers | 135 (22) | 5 (3) | 71 (31) | 59 (26) | |
| Smokers | 146 (24) | 8 (5) | 91 (39) | 47 (21) | |
| Oral tobacco use | 84 (14) | 24 (15) | 41 (18) | 19 (9) | < 0.05 |
| Emergency visits ever | |||||
| None | 358 (59) | 82 (52) | 134 (58) | 142 (64) | 0.16 |
| ≥1 emergency department visit | 128 (21) | 36 (23) | 53 (23) | 39 (17) | |
| ≥hospitalization | 125 (20) | 40 (25) | 43 (19) | 42 (19) | |
| Sick-leave during last 12 months | |||||
| None | 526 (85) | 118 (74) | 197 (85) | 211 (95) | < 0.001 |
| 1–8 days | 37 (6) | 20 (13) | 16 (7) | 1 (0) | |
| 8–30 days | 44 (7) | 20 (13) | 16 (7) | 8 (4) | |
| 30–90 days | 5 (1) | 1 (1) | 3 (1) | 1 (0) | |
| >90 days | 4 (1) | 1 (1) | 1 (0) | 2 (1) | |
| Living in an apartment | 190 (33) | 31 (21) | 74 (32) | 85 (43) | < 0.001 |
| Living in a city | 371 (64) | 102 (69) | 152 (67) | 117 (57) | < 0.05 |
| Health-related quality of life | |||||
| Symptom score | 3.7 ± 1.3 | 4.0 ± 1.1 | 3.8 ± 1.4 | 3.7 ± 1.3 | 0.12 |
| Social well-being | 5.4 ± 0.9 | 5.4 ± 0.9 | 5.3 ± 0.9 | 5.5 ± 1.0 | < 0.05 |
| Physical well-being | 4.2 ± 0.8 | 4.4 ± 0.8 | 4.3 ± 0.8 | 4.1 ± 0.8 | < 0.001 |
| Mental well-being | 5.1 ± 1.0 | 5.2 ± 1.0 | 5.1 ± 1.1 | 5.1 ± 1.0 | 0.57 |
aPollen, pets, mites, and mould.