Table 3.
Characteristics of the study population according to variables related with current asthma: children (n 669) aged 4–11 years, Salvador, Bahia, Brazil, 1997–2005
| Wheezing in previous 12 months (n 669) | Asthma symptoms (n 669) | FEV1:FVC (n 508) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Yes (n 171; 25·6 %) | Yes (n 134; 20·0 %) | ≤98 % (n 218; 42·9 %) | ||||||||
| Variable | Category | n | % | P value* | n | % | P value* | n | % | P value* |
| Sex | Male | 93 | 25·8 | 0·897 | 72 | 19·9 | 0·952 | 135 | 50·2 | 0·000 |
| Female | 78 | 25·3 | 62 | 20·1 | 83 | 34·7 | ||||
| Age (years) | ≥6 | 89 | 20·6 | <0·001 | 73 | 16·9 | 0·006 | 139 | 42·0 | 0·567 |
| <6 | 82 | 34·6 | 61 | 25·7 | 79 | 44·6 | ||||
| Birth weight (g) | <3500 | 113 | 23·4 | 0·044 | 87 | 18·0 | 0·040 | 141 | 39·9 | 0·041 |
| ≥3500 | 58 | 31·0 | 47 | 25·1 | 77 | 49·7 | ||||
| Duration of breast-feeding | Never | 52 | 28·9 | 0·168 | 41 | 22·8 | 0·205 | 80 | 41·0 | 0·597 |
| <2 months | 63 | 27·4 | 50 | 21·7 | 58 | 41·7 | ||||
| ≥2 months | 56 | 21·6 | 43 | 16·6 | 80 | 46·0 | ||||
| No. of older siblings | None | 58 | 22·1 | 0·103 | 45 | 17·2 | 0·139 | 92 | 46·7 | 0·170 |
| ≥1 | 113 | 27·8 | 89 | 21·9 | 126 | 40·5 | ||||
| Parental asthma | No | 137 | 23·8 | 0·011 | 104 | 18·1 | 0·002 | 176 | 40·4 | 0·004 |
| Yes | 34 | 36·2 | 30 | 31·9 | 42 | 58·3 | ||||
| No. of children aged <5 years of age in the household | ≤1 | 92 | 22·7 | 0·033 | 75 | 18·5 | 0·211 | 131 | 42·7 | 0·892 |
| >1 | 79 | 30·0 | 59 | 22·4 | 87 | 43·3 | ||||
| No. of persons per room | <2 | 123 | 25·2 | 0·729 | 96 | 19·7 | 0·704 | 165 | 44·7 | 0·181 |
| ≥2 | 48 | 26·5 | 38 | 21·0 | 53 | 38·1 | ||||
| Maternal schooling | High school/university | 34 | 26·0 | 0·883 | 25 | 19·1 | 0·767 | 45 | 47·9 | 0·509 |
| Secondary education | 98 | 26·1 | 79 | 21·0 | 120 | 41·1 | ||||
| Illiterate or primary | 39 | 24·1 | 30 | 18·5 | 53 | 43·4 | ||||
| Smoking during pregnancy | No | 149 | 25·1 | 0·427 | 117 | 19·7 | 0·545 | 194 | 42·9 | 0·993 |
| Yes | 22 | 29·3 | 17 | 22·7 | 24 | 42·9 | ||||
| Mould in the house in the first year of life | No | 54 | 18·8 | <0·001 | 40 | 13·9 | 0·001 | 86 | 40·6 | 0·366 |
| Yes | 117 | 30·7 | 94 | 24·7 | 132 | 44·6 | ||||
| Household pets | Never had | 67 | 21·1 | 0·011 | 52 | 16·4 | 0·024 | 89 | 37·9 | 0·033 |
| Has/had | 104 | 29·6 | 82 | 23·4 | 129 | 47·3 | ||||
| Paved street | Yes | 69 | 23·1 | 0·186 | 52 | 17·4 | 0·125 | 79 | 36·1 | 0·007 |
| No | 102 | 27·6 | 82 | 22·2 | 139 | 48·1 | ||||
| BMI (Z-score)† | <−2 | 17 | 18·5 | 0·176 | 14 | 15·2 | 0·152 | 16 | 25·4 | 0·000 |
| ≥−2 and <+1 | 128 | 26·1 | 97 | 19·8 | 163 | 42·9 | ||||
| ≥+1 | 26 | 30·2 | 23 | 26·7 | 39 | 60·0 | ||||
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.
Data are presented as number of cases (n) and prevalence (%).
*P value from χ 2 test; significant P values indicated in bold font.
†BMI Z-score: <–2 = underweight; ≥−2 and <+1 = normal; ≥+1 = overweight/obesity.