Background
Methods
Study design
Setting
Sample size
Participants
Instruments and data collection
Variables
Statistical analysis
Results
Participants
Current asthma | |||
---|---|---|---|
Total (n = 6 003) | Yes (n = 450) | No (n = 5 553) | |
Municipality
| |||
Urban | 4593 (76.5) | 337 (74.9) | 4256 (76.6) |
Rural | 1410 (23.5) | 113 (25.1) | 1297 (23.4) |
Female, n (%)
| 3438 (57.3) | 282 (62.7) | 3156 (56.8) |
Age groups, n (%)
| |||
<18 years old | 716 (11.9) | 56 (12.4) | 660 (11.9) |
18-65 years old | 3104 (51.7) | 211 (46.9) | 2893 (52.1) |
>65 years old | 2178 (36.3) | 183 (40.7) | 1995 (36.0) |
BMI
†
, n(%)
| |||
Underweight (<18) | 253 ( 5.1) | 18 ( 4.9) | 235 ( 5.1) |
Normal weight (18–25) | 2179 (43.9) | 140 (38.4) | 2039 (44.3) |
Overweight (25–30) | 1825 (36.7) | 128 (35.1) | 1697 (36.9) |
Obese (>30) | 710 (14.3) | 79 (21.6) | 631 (13.7) |
Education level
‡
, n(%)
| |||
<9 years | 3907 (65.5) | 312 (69.6) | 3595 (65.1) |
9-12 years | 1175 (19.7) | 85 (19.0) | 1090 (19.7) |
>12 years | 732 (12.3) | 40 (8.9) | 692 (12.5) |
SES
††
, n(%)
| |||
Low | 1289 (22.0) | 111 (25.2) | 1169 (21.7) |
Medium | 4137 (71.1) | 1169 (21.7) | 3831 (71.2) |
High | 405 ( 7.0) | 23 ( 5.2) | 382 ( 7.1) |
Smoking status, n(%)
| |||
Non-smoker | 4291 (71.5) | 333 (74.0) | 3958 (71.3) |
Ex-smoker | 971 (16.2) | 71 (15.8) | 900 (16.2) |
Current smoker | 741 (12.3) | 46 (10.2) | 695 (12.5) |
Unit Packs-year, n(%)
| |||
≤10 Packs-year | 4799 (79.9) | 368 (82.3) | 4431 (80.5) |
>10 Packs-year | 1150 (19.2) | 79 (17.7) | 1071 (19.5) |
ETS
‡‡
, n(%)
| |||
No | 4843 (80.7) | 347 (77.1) | 4496 (81.0) |
Yes | 1160 (19.3) | 103 (22.9) | 1057 (19.0) |
Prevalence of asthma
Current asthma
Current asthma % (95%CI) | Crude OR (95%CI) | Adjusted OR (95% CI)§ | |
---|---|---|---|
All Portuguese Population
| 6.8 ( 6.0- 7.7) | ||
NUTS II
| |||
North | 6.7 ( 5.5- 8.2) | 1.00 (Ref) | |
Centre | 6.2 ( 4.6- 8.3) | 0.92 (0.63-1.35) | |
Lisbon | 6.8 ( 5.4- 8.6) | 1.01 (0.72-1.42) | |
Alentejo/Algarve | 7.9 ( 5.4-11.3) | 1.18 (0.75-1.87) | |
Madeira/Azores | 6.6 ( 3.9-10.9) | 0.98 (0.55-1.77) | |
Municipality
| |||
Urban | 6.5 ( 5.6- 7.4) | 1.00 (Ref) | |
Rural | 7.7 ( 5.9-10.1) | 1.22 (0.87-1.69) | |
Gender
| |||
Female | 7.2 ( 6.0- 8.5) | 1.00 (Ref) | |
Male | 6.3 ( 5.2- 7.6) | 0.87 (0.66-1.14) | |
Age groups
| |||
<18 years old | 7.2 ( 5.4- 9.5) | 1.00 (Ref) | 1.00 (Ref) |
18-65 years old | 6.3 ( 5.3- 7.5) | 0.86 (0.61-1.23) | 0.94 (0.63-1.40) |
>65 years old | 8.0 ( 6.7- 9.5) | 1.11 (0.78-1.59)* |
1.51 (1.01-2.27)
§*
|
Education level
†
| |||
<9 years | 7.1 ( 6.1- 8.2) | 1.00 (Ref) | 1.00 (Ref) |
9-12 years | 7.4 ( 5.6- 9.7) | 1.05 (0.75-1.47) | 0.92 (0.64-1.32) |
>12 years | 4.5 ( 3.0- 6.6) | 0.62 (0.40-0.96) |
0.44 (0.28-0.70)
§**
|
SES
‡
| |||
Low | 6.9 ( 5.3- 8.9) | 1.00 (Ref) | |
Medium | 6.9 ( 5.9- 8.0) | 1.00 (0.73-1.37) | |
High | 6.3 ( 3.8-10.3) | 0.91 (0.50-1.66) | |
Smoking status
| |||
Non-smoker | 6.9 ( 6.0- 8.0) | 1.00 (Ref) | |
Ex-smoker | 6.3 ( 4.7- 8.5) | 0.91 (0.63-1.30) | |
Current smoker | 6.3 ( 4.3- 9.1) | 0.90 (0.59-1.34) | |
ETS
††
| |||
No | 6.1 ( 5.3- 7.0) | 1.00 (Ref) | 1.00 (Ref) |
Yes |
8.6 ( 6.7-11.0)
|
1.45 (1.06-1.97)
*
|
1.53 (1.09-2.16)
§***
|
Chronic Bronchitis
‡‡
| |||
No | 6.5 (5.7-7.4) | 1.00(Ref) | |
Yes | 14.6 (9.8-21.2) | 2.23 (1.38-3.59) | |
Rhinitis plus Sinusitis
| |||
No | 6.4 ( 5.6- 7.3) | 1.00 (Ref) | 1.00 (Ref) |
Yes |
39.1 (24.9-55.4)
|
9.34 (4.75-18.35)
**
|
13.93 (6.60-29.44)
§§
|
Rhinitis without Sinusitis
| |||
No | 4.6 ( 3.8- 5.5) | 1.00 (Ref) | 1.00 (Ref) |
Yes |
14.9 (12.6-17.6)
|
3.67 (2.79-4.82)
**
|
3.87(2.90-5.18)
§§
|
Sinusitis without Rhinitis
| |||
No | 6.7 ( 5.9- 7.6) | 1.00 (Ref) | 1.00 (Ref) |
Yes |
8.7 ( 3.3-21.2)
|
1.33 (0.47-3.76)
**
| 2.01 (0.64-6.34) |
Eczema
| |||
No | 5.1 ( 4.3- 6.1) | 1.00 (Ref) | 1.00 (Ref) |
Yes |
11.5 ( 9.6-13.7)
|
2.41 (1.84-3.17)
**
|
2.00 (1.50-2.66)
§§
|
Food allergy
| |||
No | 6.3 ( 5.5- 7.1) | 1.00 (Ref) | 1.00 (Ref) |
Yes |
15.7 (10.8-22.3)
|
2.79 (1.77-4.40)
**
|
1.89 (1.15-3.10)
§§*
|
Drug allergy
| |||
No | 6.3 ( 5.5- 7.3) | 1.00 (Ref) | 1.00 (Ref) |
Yes |
11.9 ( 8.7-16.1)
|
2.00 (1.38-2.92)
**
| 1.30 (0.86-1.95) |
Comorbidities
Current asthma subjects, % (95%CI) | Total sample, % (95%CI) | |
---|---|---|
Upper airways disease
| ||
None (Rhinitis-/Sinusitis-) | 46.9 (40.5-53.4)* | 77.2 (75.7-78.7) |
Rhinitis | 52.3 (45.8-58.6)* | 22.1 (20.7-23.6) |
Mild | 14.0 (10.4-18.8)* | 8.3 ( 7.4- 9.3) |
Intermittent | 12.1 ( 8.6-16.7) | 7.4 ( 6.6- 8.4) |
Persistent | 1.9 ( 1.0- 3.8) | 0.9 ( 0.6- 1.2) |
Moderate/Severe | 38.2 (32.3-44.5)* | 13.8 (12.6-15.1) |
Intermittent | 29.9 (24.4-36.0) | 11.1 (10.1-12.3) |
Persistent | 8.3 ( 5.7-12.0) | 2.7 ( 2.2- 3.3) |
Rhinitis+ /Sinusitis- | 46.7 (40.4-53.2)* | 21.2 (19.8-22.6) |
Sinusitis | 6.4 ( 4.3- 9.4)* | 1.6 ( 1.2- 2.1) |
Rhinitis - /Sinusitis+ | 0.9 ( 0.3- 2.2) | 0.7 ( 0.4- 1.0) |
Both (Rhinitis+/Sinusitis+) | 5.5 ( 3.5- 8.5)* | 1.0 ( 0.7- 1.3) |
Chronic bronchitis
| 5.7 ( 3.8- 8.5)* | 2.7 ( 2.2- 3.2) |
Non-respiratory allergic disease
| 55.4 (48.9-61.7)* | 33.0 (31.4-34.7) |
Eczema/atopic dermatitis | 44.3 (38.1-50.8)* | 26.1 (24.6-27.7) |
Drug allergy | 13.3 ( 9.8-17.9)* | 7.5 ( 6.7- 8.5) |
Food allergy | 12.2 ( 8.3-17.6)* | 5.3 ( 4.5- 6.1) |
Subgroup analysis
Prevalence of symptoms
Current asthma subjects, % (95%CI) | Total sample, % (95%CI) | |
---|---|---|
Asthma Symptoms
| ||
Wheeze | 89.0 (85.8-91.6)* | 18.1 (16.8-19.4) |
Nocturnal symptoms | 75.8 (70.8-80.2)* | 35.6 (33.9-37.3) |
Waking with breathlessness | 36.4 (30.7-42.6)* | 6.8 ( 5.9- 7.7) |
Waking with tightness in the chest | 39.2 (33.3-45.4)* | 11.9 (10.9-13.1) |
Waking with cough | 55.7 (49.1-62.0)* | 28.0 (26.4-29.7) |
Attack of asthma | 46.9 (41.4-52.4)* | 3.2 ( 2.6- 3.9) |
Sputum for at least 3 months
| 45.4 (39.0-51.9)* | 18.5 (17.1-19.9) |
Blocked nose
| 27.5 (22.4-33.3)* | 12.5 (11.4-13.7) |
Sinus pressure
| 25.0 (20.4-30.3)* | 11.2 (10.2-12.4) |
Healthcare resources
Current asthma subjects, % (95%CI) | Total sample, % (95%CI) | |
---|---|---|
Hospitalization because of asthma
| 25.6 (20.4-31.5) | 2.4 ( 1.9- 2.9) |
Lung function tests
| 57.4 (50.9-63.7) | 23.6 (22.2-25.2) |
Allergy tests
| ||
Any allergic test | 65.7 (59.5-71.5) | 25.2 (23.7-26.8) |
Skin-prick test | 55.2 (48.7-61.4) | 17.9 (16.6-19.3) |
Blood test | 46.7 (40.3-53.1) | 16.0 (14.7-17.4) |
Asthma medication
| ||
Any asthma medication | 60.1 (53.5-66.2) | 5.0 ( 4.2- 5.8) |
Inhaled Controller | 35.2 (29.2-41.6) | 2.9 ( 2.4- 3.6) |
Only inhaled Reliever | 21.6 (16.7-27.5) | 1.5 ( 1.1- 1.9) |
Nebulized aerosols | 36.3 (30.2-42.9) | 2.5 ( 2.0- 3.1) |
Nebulized aerosols without controller† | 17.6 (13.2-23.0) | 1.2 ( 0.9- 1.6) |
Antihistamine medication
| ||
Nasal spray | 24.9 (19.8-30.7) | 1.7 ( 1.3- 2.1) |
Oral medication | 45.3 (39.1-51.8) | 3.1 ( 2.6- 3.7) |