Sociodemographic associations with atopy
| Subjects n | n (%) atopic* | OR (95% CI) | p‐value | Adjusted OR# (95% CI) | p‐value | |
| Age | ||||||
| ≤30 yrs | 366 | 123 (34) | 1.02 (1.00–1.05)§ | 0.10 | 1.01 (0.99–1.04)§ | 0.31 |
| 31–34 yrs | 335 | 124 (37) | ||||
| ≥35 yrs | 349 | 145 (42) | ||||
| Sex | ||||||
| F | 582 | 199 (34) | 1.00 | 0.02 | 1.00 | 0.02 |
| M | 468 | 193 (41) | 1.35 (1.05–1.74) | 1.40 (1.05–1.86) | ||
| Parental allergy | ||||||
| No | 660 | 224 (34) | 1.00 | 0.01 | 1.00 | 0.002 |
| Yes | 335 | 144 (43) | 1.47 (1.12–1.92) | 1.59 (1.19–2.12) | ||
| Social class¶ | ||||||
| I/II | 168 | 67 (40) | 1.00 | 0.50 | 1.00 | 0.72 |
| III | 564 | 216 (38) | 0.94 (0.66–1.33) | 0.96 (0.67–1.38) | ||
| IV/V | 234 | 81 (35) | 0.80 (0.53–1.20) | 0.85 (0.56–1.31) | ||
| No. of brothers | ||||||
| 0 | 334 | 147 (44) | 0.76 (0.60–0.87)+ | <0.001 | 0.77 (0.66–0.89)+ | <0.001 |
| 1 | 453 | 172 (38) | ||||
| 2 | 179 | 51 (28) | ||||
| 3+ | 84 | 22 (26) | ||||
| No. of sisters | ||||||
| 0 | 340 | 125 (37) | 0.96 (0.84–1.08)ƒ | 0.48 | 0.94 (0.81–1.08)ƒ | 0.39 |
| 1 | 437 | 173 (40) | ||||
| 2 | 199 | 69 (35) | ||||
| 3+ | 74 | 25 (34) |
F: female
M: male
OR: odds ratio
CI: confidence interval
*: one or more positive skin tests to extracts of Dermataphagoides pteronyssinus, cat fur or grass pollen
#: adjusted for the other factors in the table
§: per year
+: per brother
ƒ: per sister
¶: defined by occupation: I/II professional/intermediate, III skilled nonmanual/manual, IV/V unskilled