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Richard Hubbard - One of the best experts on this subject based on the ideXlab platform.
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51-1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06-1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22-2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects of older siblings on the incidence of allergy are present within this cohort, but previous pregnancies that did not result in a live birth were not protective. Our findings suggest that exposure to antibiotics and to infections in utero is a potentially important risk factor in the development of Allergic Disease.
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51–1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06–1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22–2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects ...
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early exposure to infections and antibiotics and the incidence of Allergic Disease a birth cohort study with the west midlands general practice research database
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, J Collins, H Heatlie, Martin Frischer, Christopher Smith, Richard HubbardAbstract:Abstract Background: It has been suggested that the rise in prevalence of Allergic Disease in westernized countries is due in part to a decrease in exposure to infections and an increase in the use of antibiotics early in life. Objective: The purpose of this investigation was to quantify the relationships between (1) exposure to personal infections, infections in siblings, and use of antibiotics in early life and (2) the incidence of Allergic Disease. Methods: Using the West Midlands section of the UK General Practice Research Database, we established a historical birth cohort of children (N = 29,238). For each child, we identified all personal infections and infections in siblings and determined the use of antibiotics in early life; we also noted incident diagnoses of asthma, eczema, and hay fever. The data were analyzed through use of Cox regression. Results: There was no clear protective effect of exposure to either personal infections or infections in siblings with respect to the incidence of Allergic Disease. Antibiotic exposure was associated with an increased risk of developing Allergic Disease in a dose-related manner: having 4 or more courses of antibiotics in the first year of life was associated with an increased incidence of asthma (hazard ratio [HR], 3.13; 95% CI, 2.75-3.57), eczema (HR, 1.48; 95% CI, 1.31-1.68), and hay fever (HR, 2.12; 95% CI, 1.68-2.66). However, adjusting for consulting behavior reduced these effects (adjusted HR [95% CI]: asthma, 1.99 [1.72-2.31]; eczema, 1.01 [0.88-1.17]; hay fever, 1.14 [0.88-1.47]). Conclusions: We found no evidence that exposure to infections reduced the incidence of Allergic Disease, and infections did not explain the previous findings of a strong birth order effect in this cohort. The use of antibiotics might be associated with early diagnoses of Allergic Disease. (J Allergy Clin Immunol 2002;109:43-50.)
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siblings multiple births and the incidence of Allergic Disease a birth cohort study using the west midlands general practice research database
Thorax, 2001Co-Authors: Tricia M Mckeever, Sarah Lewis, C J P Smith, J Collins, H Heatlie, Martin Frischer, Richard HubbardAbstract:Background—The presence of older siblings reduces the risk of developing hay fever, eczema and atopy, but findings for asthma have been inconsistent. Whether twins have a reduced risk of Allergic Disease is also unclear. We have investigated these questions in a birth cohort analysis of the West Midlands General Practice Research Database (GPRD). Methods—Our birth cohort included 29 238 children. The incidence of Allergic Disease was examined according to the number of siblings, multiple births, and parental Allergic Disease and smoking habit using Cox regression. Results—There was a dose related decrease in the incidence of eczema and hay fever with increasing number of older siblings (hazard ratio for children with three or more older siblings compared with none 0.70 (95% CI 0.64 to 0.76) for eczema and 0.67 (95% CI 0.52 to 0.86) for hay fever). In contrast, the presence of older siblings increased the incidence of asthma (HR 1.17, 95% CI 1.06 to 1.29), although this eVect was strongly dependent on age of diagnosis. For children diagnosed over the age of 2 years the presence of older siblings was protective (HR 0.66, 95% CI 0.52 to 0.82), while below this age the reverse was true (HR 1.38, 95% CI 1.24 to 1.54). Members of a multiple birth had a reduced incidence of all three Allergic Diseases. Birth order and multiple birth eVects were independent of sex, maternal age, consulting behaviour, and parental allergy and smoking habit. Conclusions—The presence of older siblings and being a member of a multiple birth appears to protect against the development of eczema, hay fever, and asthma diagnosed after the age of 2. In contrast, the presence of older siblings increases the incidence of early asthma. (Thorax 2001;56:758‐762)
Tricia M Mckeever - One of the best experts on this subject based on the ideXlab platform.
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51-1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06-1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22-2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects of older siblings on the incidence of allergy are present within this cohort, but previous pregnancies that did not result in a live birth were not protective. Our findings suggest that exposure to antibiotics and to infections in utero is a potentially important risk factor in the development of Allergic Disease.
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51–1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06–1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22–2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects ...
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early exposure to infections and antibiotics and the incidence of Allergic Disease a birth cohort study with the west midlands general practice research database
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, J Collins, H Heatlie, Martin Frischer, Christopher Smith, Richard HubbardAbstract:Abstract Background: It has been suggested that the rise in prevalence of Allergic Disease in westernized countries is due in part to a decrease in exposure to infections and an increase in the use of antibiotics early in life. Objective: The purpose of this investigation was to quantify the relationships between (1) exposure to personal infections, infections in siblings, and use of antibiotics in early life and (2) the incidence of Allergic Disease. Methods: Using the West Midlands section of the UK General Practice Research Database, we established a historical birth cohort of children (N = 29,238). For each child, we identified all personal infections and infections in siblings and determined the use of antibiotics in early life; we also noted incident diagnoses of asthma, eczema, and hay fever. The data were analyzed through use of Cox regression. Results: There was no clear protective effect of exposure to either personal infections or infections in siblings with respect to the incidence of Allergic Disease. Antibiotic exposure was associated with an increased risk of developing Allergic Disease in a dose-related manner: having 4 or more courses of antibiotics in the first year of life was associated with an increased incidence of asthma (hazard ratio [HR], 3.13; 95% CI, 2.75-3.57), eczema (HR, 1.48; 95% CI, 1.31-1.68), and hay fever (HR, 2.12; 95% CI, 1.68-2.66). However, adjusting for consulting behavior reduced these effects (adjusted HR [95% CI]: asthma, 1.99 [1.72-2.31]; eczema, 1.01 [0.88-1.17]; hay fever, 1.14 [0.88-1.47]). Conclusions: We found no evidence that exposure to infections reduced the incidence of Allergic Disease, and infections did not explain the previous findings of a strong birth order effect in this cohort. The use of antibiotics might be associated with early diagnoses of Allergic Disease. (J Allergy Clin Immunol 2002;109:43-50.)
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siblings multiple births and the incidence of Allergic Disease a birth cohort study using the west midlands general practice research database
Thorax, 2001Co-Authors: Tricia M Mckeever, Sarah Lewis, C J P Smith, J Collins, H Heatlie, Martin Frischer, Richard HubbardAbstract:Background—The presence of older siblings reduces the risk of developing hay fever, eczema and atopy, but findings for asthma have been inconsistent. Whether twins have a reduced risk of Allergic Disease is also unclear. We have investigated these questions in a birth cohort analysis of the West Midlands General Practice Research Database (GPRD). Methods—Our birth cohort included 29 238 children. The incidence of Allergic Disease was examined according to the number of siblings, multiple births, and parental Allergic Disease and smoking habit using Cox regression. Results—There was a dose related decrease in the incidence of eczema and hay fever with increasing number of older siblings (hazard ratio for children with three or more older siblings compared with none 0.70 (95% CI 0.64 to 0.76) for eczema and 0.67 (95% CI 0.52 to 0.86) for hay fever). In contrast, the presence of older siblings increased the incidence of asthma (HR 1.17, 95% CI 1.06 to 1.29), although this eVect was strongly dependent on age of diagnosis. For children diagnosed over the age of 2 years the presence of older siblings was protective (HR 0.66, 95% CI 0.52 to 0.82), while below this age the reverse was true (HR 1.38, 95% CI 1.24 to 1.54). Members of a multiple birth had a reduced incidence of all three Allergic Diseases. Birth order and multiple birth eVects were independent of sex, maternal age, consulting behaviour, and parental allergy and smoking habit. Conclusions—The presence of older siblings and being a member of a multiple birth appears to protect against the development of eczema, hay fever, and asthma diagnosed after the age of 2. In contrast, the presence of older siblings increases the incidence of early asthma. (Thorax 2001;56:758‐762)
Sarah Lewis - One of the best experts on this subject based on the ideXlab platform.
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51-1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06-1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22-2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects of older siblings on the incidence of allergy are present within this cohort, but previous pregnancies that did not result in a live birth were not protective. Our findings suggest that exposure to antibiotics and to infections in utero is a potentially important risk factor in the development of Allergic Disease.
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51–1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06–1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22–2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects ...
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early exposure to infections and antibiotics and the incidence of Allergic Disease a birth cohort study with the west midlands general practice research database
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, J Collins, H Heatlie, Martin Frischer, Christopher Smith, Richard HubbardAbstract:Abstract Background: It has been suggested that the rise in prevalence of Allergic Disease in westernized countries is due in part to a decrease in exposure to infections and an increase in the use of antibiotics early in life. Objective: The purpose of this investigation was to quantify the relationships between (1) exposure to personal infections, infections in siblings, and use of antibiotics in early life and (2) the incidence of Allergic Disease. Methods: Using the West Midlands section of the UK General Practice Research Database, we established a historical birth cohort of children (N = 29,238). For each child, we identified all personal infections and infections in siblings and determined the use of antibiotics in early life; we also noted incident diagnoses of asthma, eczema, and hay fever. The data were analyzed through use of Cox regression. Results: There was no clear protective effect of exposure to either personal infections or infections in siblings with respect to the incidence of Allergic Disease. Antibiotic exposure was associated with an increased risk of developing Allergic Disease in a dose-related manner: having 4 or more courses of antibiotics in the first year of life was associated with an increased incidence of asthma (hazard ratio [HR], 3.13; 95% CI, 2.75-3.57), eczema (HR, 1.48; 95% CI, 1.31-1.68), and hay fever (HR, 2.12; 95% CI, 1.68-2.66). However, adjusting for consulting behavior reduced these effects (adjusted HR [95% CI]: asthma, 1.99 [1.72-2.31]; eczema, 1.01 [0.88-1.17]; hay fever, 1.14 [0.88-1.47]). Conclusions: We found no evidence that exposure to infections reduced the incidence of Allergic Disease, and infections did not explain the previous findings of a strong birth order effect in this cohort. The use of antibiotics might be associated with early diagnoses of Allergic Disease. (J Allergy Clin Immunol 2002;109:43-50.)
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siblings multiple births and the incidence of Allergic Disease a birth cohort study using the west midlands general practice research database
Thorax, 2001Co-Authors: Tricia M Mckeever, Sarah Lewis, C J P Smith, J Collins, H Heatlie, Martin Frischer, Richard HubbardAbstract:Background—The presence of older siblings reduces the risk of developing hay fever, eczema and atopy, but findings for asthma have been inconsistent. Whether twins have a reduced risk of Allergic Disease is also unclear. We have investigated these questions in a birth cohort analysis of the West Midlands General Practice Research Database (GPRD). Methods—Our birth cohort included 29 238 children. The incidence of Allergic Disease was examined according to the number of siblings, multiple births, and parental Allergic Disease and smoking habit using Cox regression. Results—There was a dose related decrease in the incidence of eczema and hay fever with increasing number of older siblings (hazard ratio for children with three or more older siblings compared with none 0.70 (95% CI 0.64 to 0.76) for eczema and 0.67 (95% CI 0.52 to 0.86) for hay fever). In contrast, the presence of older siblings increased the incidence of asthma (HR 1.17, 95% CI 1.06 to 1.29), although this eVect was strongly dependent on age of diagnosis. For children diagnosed over the age of 2 years the presence of older siblings was protective (HR 0.66, 95% CI 0.52 to 0.82), while below this age the reverse was true (HR 1.38, 95% CI 1.24 to 1.54). Members of a multiple birth had a reduced incidence of all three Allergic Diseases. Birth order and multiple birth eVects were independent of sex, maternal age, consulting behaviour, and parental allergy and smoking habit. Conclusions—The presence of older siblings and being a member of a multiple birth appears to protect against the development of eczema, hay fever, and asthma diagnosed after the age of 2. In contrast, the presence of older siblings increases the incidence of early asthma. (Thorax 2001;56:758‐762)
Christopher Smith - One of the best experts on this subject based on the ideXlab platform.
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51–1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06–1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22–2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects ...
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the importance of prenatal exposures on the development of Allergic Disease a birth cohort study using the west midlands general practice database
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, Christopher Smith, Richard HubbardAbstract:The etiology of Allergic Disease is not understood, but a decreased exposure to infection may play an important role. There are few published data on the impact of change in microbial exposure during pregnancy on the child's risk of developing Allergic Disease. Using a birth cohort of 24,690 children, derived from the West Midlands General Practice Research Database, we investigated a number of perinatal exposures on the incidence of asthma, eczema, and hay fever. Our findings suggest that exposure to antibiotics in utero is associated with an increased risk of asthma in a dose-related manner (more than two courses of antibiotics compared with none adjusted hazard ratio [HR] 1.68; 95% confidence interval [CI], 1.51-1.87), and similar associations are present for eczema (adjusted HR 1.17; 95% CI, 1.06-1.29) and hay fever (adjusted HR 1.56; 95% CI, 1.22-2.01). Exposure to a range of infections in utero was also associated with a small increased risk of developing Allergic Disease. Strong protective effects of older siblings on the incidence of allergy are present within this cohort, but previous pregnancies that did not result in a live birth were not protective. Our findings suggest that exposure to antibiotics and to infections in utero is a potentially important risk factor in the development of Allergic Disease.
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early exposure to infections and antibiotics and the incidence of Allergic Disease a birth cohort study with the west midlands general practice research database
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, J Collins, H Heatlie, Martin Frischer, Christopher Smith, Richard HubbardAbstract:Abstract Background: It has been suggested that the rise in prevalence of Allergic Disease in westernized countries is due in part to a decrease in exposure to infections and an increase in the use of antibiotics early in life. Objective: The purpose of this investigation was to quantify the relationships between (1) exposure to personal infections, infections in siblings, and use of antibiotics in early life and (2) the incidence of Allergic Disease. Methods: Using the West Midlands section of the UK General Practice Research Database, we established a historical birth cohort of children (N = 29,238). For each child, we identified all personal infections and infections in siblings and determined the use of antibiotics in early life; we also noted incident diagnoses of asthma, eczema, and hay fever. The data were analyzed through use of Cox regression. Results: There was no clear protective effect of exposure to either personal infections or infections in siblings with respect to the incidence of Allergic Disease. Antibiotic exposure was associated with an increased risk of developing Allergic Disease in a dose-related manner: having 4 or more courses of antibiotics in the first year of life was associated with an increased incidence of asthma (hazard ratio [HR], 3.13; 95% CI, 2.75-3.57), eczema (HR, 1.48; 95% CI, 1.31-1.68), and hay fever (HR, 2.12; 95% CI, 1.68-2.66). However, adjusting for consulting behavior reduced these effects (adjusted HR [95% CI]: asthma, 1.99 [1.72-2.31]; eczema, 1.01 [0.88-1.17]; hay fever, 1.14 [0.88-1.47]). Conclusions: We found no evidence that exposure to infections reduced the incidence of Allergic Disease, and infections did not explain the previous findings of a strong birth order effect in this cohort. The use of antibiotics might be associated with early diagnoses of Allergic Disease. (J Allergy Clin Immunol 2002;109:43-50.)
Martin Frischer - One of the best experts on this subject based on the ideXlab platform.
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early exposure to infections and antibiotics and the incidence of Allergic Disease a birth cohort study with the west midlands general practice research database
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Tricia M Mckeever, Sarah Lewis, J Collins, H Heatlie, Martin Frischer, Christopher Smith, Richard HubbardAbstract:Abstract Background: It has been suggested that the rise in prevalence of Allergic Disease in westernized countries is due in part to a decrease in exposure to infections and an increase in the use of antibiotics early in life. Objective: The purpose of this investigation was to quantify the relationships between (1) exposure to personal infections, infections in siblings, and use of antibiotics in early life and (2) the incidence of Allergic Disease. Methods: Using the West Midlands section of the UK General Practice Research Database, we established a historical birth cohort of children (N = 29,238). For each child, we identified all personal infections and infections in siblings and determined the use of antibiotics in early life; we also noted incident diagnoses of asthma, eczema, and hay fever. The data were analyzed through use of Cox regression. Results: There was no clear protective effect of exposure to either personal infections or infections in siblings with respect to the incidence of Allergic Disease. Antibiotic exposure was associated with an increased risk of developing Allergic Disease in a dose-related manner: having 4 or more courses of antibiotics in the first year of life was associated with an increased incidence of asthma (hazard ratio [HR], 3.13; 95% CI, 2.75-3.57), eczema (HR, 1.48; 95% CI, 1.31-1.68), and hay fever (HR, 2.12; 95% CI, 1.68-2.66). However, adjusting for consulting behavior reduced these effects (adjusted HR [95% CI]: asthma, 1.99 [1.72-2.31]; eczema, 1.01 [0.88-1.17]; hay fever, 1.14 [0.88-1.47]). Conclusions: We found no evidence that exposure to infections reduced the incidence of Allergic Disease, and infections did not explain the previous findings of a strong birth order effect in this cohort. The use of antibiotics might be associated with early diagnoses of Allergic Disease. (J Allergy Clin Immunol 2002;109:43-50.)
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siblings multiple births and the incidence of Allergic Disease a birth cohort study using the west midlands general practice research database
Thorax, 2001Co-Authors: Tricia M Mckeever, Sarah Lewis, C J P Smith, J Collins, H Heatlie, Martin Frischer, Richard HubbardAbstract:Background—The presence of older siblings reduces the risk of developing hay fever, eczema and atopy, but findings for asthma have been inconsistent. Whether twins have a reduced risk of Allergic Disease is also unclear. We have investigated these questions in a birth cohort analysis of the West Midlands General Practice Research Database (GPRD). Methods—Our birth cohort included 29 238 children. The incidence of Allergic Disease was examined according to the number of siblings, multiple births, and parental Allergic Disease and smoking habit using Cox regression. Results—There was a dose related decrease in the incidence of eczema and hay fever with increasing number of older siblings (hazard ratio for children with three or more older siblings compared with none 0.70 (95% CI 0.64 to 0.76) for eczema and 0.67 (95% CI 0.52 to 0.86) for hay fever). In contrast, the presence of older siblings increased the incidence of asthma (HR 1.17, 95% CI 1.06 to 1.29), although this eVect was strongly dependent on age of diagnosis. For children diagnosed over the age of 2 years the presence of older siblings was protective (HR 0.66, 95% CI 0.52 to 0.82), while below this age the reverse was true (HR 1.38, 95% CI 1.24 to 1.54). Members of a multiple birth had a reduced incidence of all three Allergic Diseases. Birth order and multiple birth eVects were independent of sex, maternal age, consulting behaviour, and parental allergy and smoking habit. Conclusions—The presence of older siblings and being a member of a multiple birth appears to protect against the development of eczema, hay fever, and asthma diagnosed after the age of 2. In contrast, the presence of older siblings increases the incidence of early asthma. (Thorax 2001;56:758‐762)
