| Author, year (reference) | Location | Study population | Age (years) | H pylori measure | Definition of outcome | Major findings: Condition and OR (95% CI) in relation to H pylori+ | |
| Matricardi, 2000 (43) | Caserta, Italy | 1659 Italian male military cadets | 17–24 | IgG ELISA | Total IgE | Atopy For H pylori, T gondii, Hep A | |
| Atopy: logRU>1.2 | 1 v 0 | 0.70 (0.52 to 0.94)* | |||||
| Non-atopic: logRU <0 | 2 or 3 v 0 | 0.37 (0.22 to 0.63)* | |||||
| Kosunen, 2002 (44) | Vammala, Finland | 326 and 319 healthy subjects in 1973 and 1994, respectively | 15–54 | IgA & IgG ELISA | Atopy: any IgE >0.35 IU/ml | Atopy | |
| In 1973: | 0.97 (0.46 to 2.05) | ||||||
| In 1994: | 0.20 (0.05 to 0.71)* | ||||||
| McCune, 2003 (45) | Bristol, UK | 3244 healthy subjects | 20–59 | 13C-urea breath test | Current medications for the disorders: asthma (inhalers), allergic rhinitis (antihistamines), and eczema (topical corticosteroids) | Asthma: | 0.78 (0.59 to 1.05) |
| Allergic rhinitis: | 0.60 (0.36 to 1.00)* | ||||||
| Eczema: | 0.29 (0.06 to 1.26) | ||||||
| Any of the three: | 0.70 (0.54 to 0.91)* | ||||||
| Linneberg, 2003 (46) | Denmark | 1101 subjects | 15–69 | IgG ELISA | Self-reported allergic rhinitis | Atopy | 0.78 (0.57 to 1.08) |
| Specific IgE to 6 allergens | Allergic rhinitis: | 0.74 (0.51 to 1.07) | |||||
| Atopy: any IgE >0.35 kU/l | |||||||
| Jarvis, 2004 (47) | East Anglia, UK | 907 randomly invited from 15,000 young adults | 20–44 | IgG ELISA | Self-reported symptoms in the prior year suggestive of hay fever and asthma | Hay fever/nasal allergies: | 1.01 (0.70 to 1.52) |
| Wheeze with no cold: | 0.80 (0.51 to 1.24) | ||||||
| Total IgE and specific IgE to house dust mite, cat, grass, Cladosporium, and birch | Allergy to grass: | 0.65 (0.43 to 0.99)* | |||||
| Allergy to >1 allergens: | 1.13 (0.81 to 1.59) | ||||||
| Radon, 2004 (48) | Northern Germany | 321 with blood samples from 930 randomly selected from 3112 inhabitants | 18–44 | IgG ELISA, IgG CagA | Specific IgE against a panel of aeroallergens | Atopy: | 0.70 (0.39 to 1.28) |
| Atopy: any IgE>0.70 kU/l | |||||||
| von Hertzen, 2006 (49) | Eastern Finland, Western Russia | Healthy adults; 790 from Finland, 387 from Russia | 25–54 | IgG ELISA | Skin prick testing with a panel of 11 common airborne allergens | Atopy, in Russians: | 0.55, p<0.01*† |
| Atopy: any wheal diameter ⩾3 mm | In Finns: | 0.72, p = 0.53† | |||||
| Janson, 2007 (50) | Iceland, Sweden, Estonia | 1249 healthy adults | Mean 42 | IgG ELISA | Detection of specific Atopy: | Atopy: | 0.57 (0.43 to 0.77)* |
| any IgE >0.35 kU/l | For IgG antibodies to ⩽3 specified infectious Atopy: | 0.70 (0.52 to 0.94)* | |||||
| Self-reported hay fever, asthma | Allergic asthma: | 0.55 (0.34 to 0.89)* | |||||
| in the prior year | Allergic rhinitis: | 0.59 (0.42 to 0.83)* | |||||
| Chen, 2007 (51) | USA | 7663 adults | 20–90; Mean, 43 | IgG ELISA, IgG CagA | Self-reported asthma and hay fever (current and lifetime) | OR in relation to CagA+, Ever asthma: | 0.79 (0.63 to 0.99)* |
| Skin sensitisation tests | Onset age ⩽15: | 0.63 (0.43 to 0.93)* | |||||
| Herbarth, 2007 (52) | Germany | 2487 children | Mean 6 | 13C-urea breath test | Lifetime physician-diagnosed eczema | Eczema: | 0.37, p<0.01*† |
| Shiotani, 2007 (53) | Japan | 777 university students | Mean 19 | IgG ELISA | Self-reported atopic dermatitis, bronchial asthma, allergic rhinoconjunctivitis, urticaria | Any allergic disease: | 0.60 (0.40 to 0.90)* |
| Chen, 2007 (54) | USA | 7412 adults | 3–85, Mean 25 | IgG ELISA | Self-reported asthma and hay fever (current and lifetime) | Ever asthma: (in ⩽19 years) | 0.65 (0.45 to 1.06) |
| Current asthma: (in ⩽13 years) | 0.41 (0.24 to 0.69)* | ||||||
| Early childhood: (onset <5 years) | 0.58 (0.38 to 0.88)* | ||||||
*p<0.05.
†CI was not estimated because information on covariates is not available; the study reported a p-value adjusted for covariates only.