Studies showing a relation between family size and atopic disease that could not be included in figures 1 to 4 (no frequencies/odds ratio reported or outcome did not fit in one of the four categories)
| Author and year | Outcome measured | Findings | Measure of association |
|---|---|---|---|
| Bråbäck et al, 199545 n=2232 | SPT | The number of siblings and domestic crowding were inversely related to sensitisation | OR=0.58 (0.43 to 0.77) for number of persons per room |
| Burr et al, 199747 n=437 for SPT n=338 for IgE | SPT, IgE, wheezing, eczema, hay fever (children with family history of atopy) | There was a non-significant negative association of SPT and IgE with number of older siblings | p=0.13 for SPT p=0.12 for IgE |
| Mattes et al, 19989 n=3165 | Atopic disorder (asthma, hay fever, or eczema) | Inverse relation between number of older siblings and atopic disease | OR=0.4 (0.19 to 0.83) for +3 older siblings OR=1.14 (0.70 to 1.85) for +3 younger siblings |
| Strachan et al, 19975 n=11042 | Inhalant allergy (cat, pollen, or dust) and non-inhalant allergy (insect bites or something else) | Inhalant allergy was inversely related with the number of siblings | OR=0.76 (0.59 to 0.97) (not adjusted) |
| Tariq et al, 199853 n=1215 for atopic illness n=981 for SPT | Atopic disorder (asthma, eczema, or hay fever) SPT | Weak inverse relation of number of siblings with atopic illness and SPT | PR=0.41 for atopic illness (not significant) PR=0.61 for SPT (not significant), 4 siblings v no |
| Taylor et al, 198319 n=12743 | Eczema, hay fever, wheezing, and asthma | Having older siblings was inversely associated with hay fever, no associations with eczema of asthma | PR=0.56 of having older siblings v no older siblings for hay fever (no CI or p value provided) |
| Weitzman et al, 199041 n=15224 | Asthma and use of asthma medication | Asthma was positively associated with having a large family size (more than 6 members) | OR=1.9 (1.2 to 3.1) for 6 or more family members v less than six |
| Attena et al, 199928 | Medical diagnosis of asthma | Firstborn had 1.89 times more asthma than other siblings | OR=1.89 for firstborn (p=0.048) |
| Lewis et al, 1998 n=716217 | Eczema | Significant trend of increased risk of eczema at the age of 16 in firstborn compared with subsequent children. | Graphical presentation: OR≊0.92 for the third child, and OR≊0.78 for the fourth child compared with the first. |
| Moyes et al, 1995 n=57724 | Cough and wheeze | Cough and wheeze was more common in primary children | Cough: primary children OR=1.3 (1 to 1.7), wheeze: OR=1.5 (1 to 2.3) |