Prevalence of atopy, asthma and hay fever by age, sex, parental allergy, social class, and sibship
| Atopy | Asthma | Atopic asthma | Hay fever | Grass-positive hay fever | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| N | n (%) | OR (95% CI); p† | n (%) | OR (95% CI); p† | n (%) | OR (95% CI); p† | n (%) | OR (95% CI); p† | n (%) | OR (95% CI); p† | |
| *54 participants could not be classified by their occupation (unemployed, Armed Forces etc). | |||||||||||
| †Odds ratios (95% confidence intervals) and p values adjusted for the other factors in the table. | |||||||||||
| Age (years) | |||||||||||
| ⩽30 | 292 | 96 (33%) | 1.03 (1.00 to 1.06) | 44 (15%) | 0.97 (0.92 to 1.02) | 31 (11%) | 1.02 (0.97 to 1.08) | 80 (27%) | 1.03 (0.99 to 1.07) | 45 (16%) | 1.03 (0.98 to 1.08) |
| 31–34 | 250 | 94 (38%) | Per year | 34 (14%) | Per year | 27 (11%) | Per year | 70 (28%) | Per year | 41 (16%) | Per year |
| ⩾35 | 199 | 79 (40%) | p = 0.17 | 28 (14%) | p = 0.26 | 24 (12%) | p = 0.44 | 63 (32%) | p = 0.20 | 35 (18%) | p = 0.23 |
| Sex | |||||||||||
| Female | 419 | 138 (33%) | 1.48 (1.05 to 2.09) | 56 (13%) | 1.57 (0.98 to 2.51) | 38 (9%) | 2.02 (1.19 to 3.44) | 127 (30%) | 0.94 (0.65 to 1.36) | 69 (17%) | 1.15 (0.73 to 1.80) |
| Male | 322 | 131 (41%) | p = 0.02 | 50 (16%) | p = 0.06 | 44 (14%) | p = 0.01 | 86 (27%) | p = 0.74 | 52 (16%) | p = 0.55 |
| Parental allergic disease | |||||||||||
| − | 469 | 148 (32%) | 1.75 (1.25 to 2.47) | 50 (11%) | 2.26 (1.44 to 3.54) | 35 (8%) | 2.78 (1.66 to 4.64) | 107 (23%) | 2.18 (1.52 to 3.11) | 53 (11%) | 2.56 (1.66 to 3.95) |
| + | 340 | 102 (43%) | p = 0.001 | 50 (21%) | p<0.001 | 41 (17%) | p<0.001 | 93 (39%) | p<0.001 | 59 (25%) | p<0.001 |
| Social class* | |||||||||||
| I/II | 106 | 44 (40%) | 1.00 | 19 (18%) | 1.00 | 16 (15%) | 1.00 | 39 (37%) | 1.00 | 23 (22%) | 1.00 |
| III | 415 | 155 (38%) | 0.93 (0.60 to 1.45) | 57 (14%) | 0.75 (0.42 to 1.35) | 45 (11%) | 0.74 (0.39 to 1.40) | 114 (27%) | 0.65 (0.41 to 1.03) | 67 (16%) | 0.68 (0.39 to 1.19) |
| IV/V | 166 | 53 (33%) | 0.77 (0.46 to 1.31) | 20 (12%) | 0.67 (0.33 to 1.37) | 13 (8%) | 0.56 (0.25 to 1.26) | 43 (26%) | 0.73 (0.42 to 1.27) | 24 (15%) | 0.77 (0.39 to 1.49) |
| p = 0.57 | p = 0.53 | p = 0.37 | p = 0.19 | p = 0.41 | |||||||
| No. of siblings | |||||||||||
| 0/1 | 306 | 131 (43%) | 0.85 (0.74 to 0.97) | 54 (18%) | 0.90 (0.74 to 1.08) | 46 (15%) | 0.79 (0.63 to 1.00) | 108 (35%) | 0.81 (0.69 to 0.94) | 78 (26%) | 0.64 (0.51 to 0.80) |
| 2 | 223 | 75 (34%) | Per unit increase | 26 (12%) | Per unit increase | 21 (10%) | Per unit increase | 57 (26%) | Per unit increase | 25 (11%) | Per unit increase |
| 3 | 118 | 38 (32%) | p = 0.02 | 15 (13%) | p = 0.25 | 8 (7%) | p = 0.04 | 29 (25%) | p = 0.004 | 8 (7%) | p<0.001 |
| 4+ | 94 | 25 (27%) | 11 (12%) | 7 (8%) | 19 (20%) | 10 (11%) | |||||