Pertussis vaccination in infancy and asthma or allergy in later childhood: birth cohort study
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《英国医生杂志》
1 Bristol Royal Hospital for Children, Department of Respiratory Medicine, Bristol BS2 8BJ, 2 Avon Longitudinal Study of Parents and Children, University of Bristol, Department of Community-based Medicine, Bristol BS8 1TQ, 3 St Michael's Hospital, Ear, Nose, and Throat Department, Bristol BS2 8EG
Correspondence to: A Maitra dramaitra@yahoo.co.uk
Introduction
Participants were the 13 971 children who survived to 1 year in the Avon longitudinal study of parents and children. The study method has been described previously,5 and details can be found on the study website (www.alspac.bris.ac.uk). We obtained the vaccination status for each child from the child health surveillance database. We categorised children with regard to pertussis as fully vaccinated (completed a primary course of diphtheria, tetanus, and pertussis vaccination), partially vaccinated (completed a primary course of diphtheria and tetanus but did not receive pertussis vaccine) or non-vaccinated (no vaccinations). We excluded other combinations from analysis. We obtained three wheezing outcomes based on parental self report questionnaires (asthma at 69-81 months, wheeze with whistling on the chest at 69-81 months, and asthma diagnosed by a doctor at 91 months) and one atopy outcome based on skin prick tests at age 7 years. We defined atopy as one or more positive reactions (wheal 2 mm) to a panel of three common allergens. We selected several variables as potential confounders of the relation between exposure and outcome, which were, however, not considered to be in the causal pathway. These were, from mother's questionnaire data: maternal education, maternal smoking during pregnancy, maternal history of asthma or eczema, maternal financial difficulties, damp housing, overcrowding, child's ethnicity, number of siblings, contact with cats in the home, duration of breast feeding, and passive exposure to tobacco smoke; and, from medical records: birth weight, sex, gestational age, and maternal age at delivery. We used Pearson's 2 (or Fisher's exact test if the predicted number of subjects in any category was less than five) for our data analysis of univariable associations between vaccination status and possible confounders and principal outcomes. We used multivariable logistic regression models to evaluate associations between immunisation status and asthma and allergy outcomes while controlling for potential confounders.
Vaccination history was available for 13 810 children, of whom 13 109 (94.9%) were fully vaccinated, 446 did not have pertussis vaccination (340 non-vaccinated; 106 partially vaccinated), and 255 had some other combination. The table shows numbers of subjects with outcome data for each of the principal outcomes. The cumulative prevalence of asthma diagnosed by doctors was 20.3% (n = 1597) at 91 months. The prevalence of reported asthma at 69-81 months was 12.4% (n = 1024), reported wheeze with whistling at 69-81 months 9.8% (n = 798) and atopy at 7 years 20.5% (n = 1324). The table shows the adjusted and unadjusted odds ratios and 95% confidence intervals from logistic regressions for each of the principal outcomes. Although unadjusted analyses showed significant associations (asthma at 69-81 months, P = 0.05; doctor diagnosed asthma, 91 months, P = 0.005), it should be noted that, because of small numbers in some groups, the confidence intervals were wide and the results did not support the hypothesis. When we adjusted for potential confounding factors we detected no significant associations (P = 0.1-0.8).
Odds ratios with 95% confidence intervals for outcome variables according to pertussis vaccination status
Comment
Odent MR, Kimmel T. Pertussis vaccination and asthma: is there a link? JAMA 1994;272: 592-593.
Kemp T, Pearce N, Fitzharris P, Crane J, Fergusson D, St George I, Wickens K, Beasley R. Is infant immunization a risk factor for childhood asthma or allergy? Epidemiology 1997;8: 678-680.
Nilsson L, Kjellman N-IM, Bj?rksten B. A randomised controlled trial of the effect of pertussis vaccines on atopic disease. Arch Pediatr Adolescent Med 1998;152: 734-738.
Henderson AJ, North K, Griffiths M, Harvey I, Golding J, ALSPAC Study Team. Pertussis vaccination and wheezing illnesses in young children: prospective cohort study. BMJ 1999;318: 1173-1176.
Golding J, Pembrey M, Jones R., ALSPAC Study Team. ALSPAC—the Avon longitudinal study of parents and children I. Study methodology. Paediatr Perinatal Epidemiol 2001;15: 74-87.(Anirban Maitra, clinical )
Correspondence to: A Maitra dramaitra@yahoo.co.uk
Introduction
Participants were the 13 971 children who survived to 1 year in the Avon longitudinal study of parents and children. The study method has been described previously,5 and details can be found on the study website (www.alspac.bris.ac.uk). We obtained the vaccination status for each child from the child health surveillance database. We categorised children with regard to pertussis as fully vaccinated (completed a primary course of diphtheria, tetanus, and pertussis vaccination), partially vaccinated (completed a primary course of diphtheria and tetanus but did not receive pertussis vaccine) or non-vaccinated (no vaccinations). We excluded other combinations from analysis. We obtained three wheezing outcomes based on parental self report questionnaires (asthma at 69-81 months, wheeze with whistling on the chest at 69-81 months, and asthma diagnosed by a doctor at 91 months) and one atopy outcome based on skin prick tests at age 7 years. We defined atopy as one or more positive reactions (wheal 2 mm) to a panel of three common allergens. We selected several variables as potential confounders of the relation between exposure and outcome, which were, however, not considered to be in the causal pathway. These were, from mother's questionnaire data: maternal education, maternal smoking during pregnancy, maternal history of asthma or eczema, maternal financial difficulties, damp housing, overcrowding, child's ethnicity, number of siblings, contact with cats in the home, duration of breast feeding, and passive exposure to tobacco smoke; and, from medical records: birth weight, sex, gestational age, and maternal age at delivery. We used Pearson's 2 (or Fisher's exact test if the predicted number of subjects in any category was less than five) for our data analysis of univariable associations between vaccination status and possible confounders and principal outcomes. We used multivariable logistic regression models to evaluate associations between immunisation status and asthma and allergy outcomes while controlling for potential confounders.
Vaccination history was available for 13 810 children, of whom 13 109 (94.9%) were fully vaccinated, 446 did not have pertussis vaccination (340 non-vaccinated; 106 partially vaccinated), and 255 had some other combination. The table shows numbers of subjects with outcome data for each of the principal outcomes. The cumulative prevalence of asthma diagnosed by doctors was 20.3% (n = 1597) at 91 months. The prevalence of reported asthma at 69-81 months was 12.4% (n = 1024), reported wheeze with whistling at 69-81 months 9.8% (n = 798) and atopy at 7 years 20.5% (n = 1324). The table shows the adjusted and unadjusted odds ratios and 95% confidence intervals from logistic regressions for each of the principal outcomes. Although unadjusted analyses showed significant associations (asthma at 69-81 months, P = 0.05; doctor diagnosed asthma, 91 months, P = 0.005), it should be noted that, because of small numbers in some groups, the confidence intervals were wide and the results did not support the hypothesis. When we adjusted for potential confounding factors we detected no significant associations (P = 0.1-0.8).
Odds ratios with 95% confidence intervals for outcome variables according to pertussis vaccination status
Comment
Odent MR, Kimmel T. Pertussis vaccination and asthma: is there a link? JAMA 1994;272: 592-593.
Kemp T, Pearce N, Fitzharris P, Crane J, Fergusson D, St George I, Wickens K, Beasley R. Is infant immunization a risk factor for childhood asthma or allergy? Epidemiology 1997;8: 678-680.
Nilsson L, Kjellman N-IM, Bj?rksten B. A randomised controlled trial of the effect of pertussis vaccines on atopic disease. Arch Pediatr Adolescent Med 1998;152: 734-738.
Henderson AJ, North K, Griffiths M, Harvey I, Golding J, ALSPAC Study Team. Pertussis vaccination and wheezing illnesses in young children: prospective cohort study. BMJ 1999;318: 1173-1176.
Golding J, Pembrey M, Jones R., ALSPAC Study Team. ALSPAC—the Avon longitudinal study of parents and children I. Study methodology. Paediatr Perinatal Epidemiol 2001;15: 74-87.(Anirban Maitra, clinical )