The Christchurch Health and Development Study comprises 1,265 children born in 1977. The 23 children who received no diphtheria/pertussis/tetanus (DPT) and polio immunizations had no recorded asthma episodes or consultations for asthma or other allergic illness before age 10 years; in the immunized children, 23.1% had asthma episodes, 22.5% asthma consultations, and 30.0% consultations for other allergic illness. Similar differences were observed at ages 5 and 16 years. These findings do not appear to be due to differential use of health services (although this possibility cannot be excluded) or con-founding by ethnicity, socioeconomic status, parental atopy, or parental smoking.

A mother's prepregnancy obesity has been suggested as a risk factor for having offspring with an abdominal wall defect. We evaluated this hypothesis among 104 cases of gastroschisis--a severe birth defect of the abdominal wall most prevalent in infants of young women--and 220 controls with no defect. Using Quetelet's index (QI = weight in kg/height in m2) as a measure of body mass, we found a higher risk of gastroschisis (odds ratio (OR) = 3.2; 95% confidence interval (CI) = 1.4-7.3) for underweight mothers (QI<18.1 kg/m2) and a lower risk (OR = 0.2; 0.05-0.9) for overweight mothers (QI>28.3 kg/m2) as compared with mothers of normal weight. As QI was correlated to height, with the correlation varying according to mother's ethnicity and age, we adjusted for these factors in the analysis; the adjusted values approximated the unadjusted values. Evaluation of QI as a continuous variable showed that, for every unit increase in QI, the risk for gastroschisis decreased by about 11%. Sociodemographic, pregnancy, and nutrient factors did not confound the association. These results suggest that low prepregnancy body mass rather than obesity is a risk factor for gastroschisis.

No abstract

Objective : As in other English‐speaking countries, asthma is a major and increasing health problem in New Zealand. This study examined the risk factors for asthma in children aged 7–9. Methods : Cases and controls were randomly selected from participants in the Wellington arm of the International Study of Asthma and Allergies in Childhood (ISAAC). Cases were children with a previous diagnosis of asthma and current medication use (n=233), and controls were children with no history of wheezing and no diagnosis of asthma (n=241). Results : After controlling for confounders, factors significantly associated with asthma were maternal (OR=3.36, 95% Cl 1.88–5.99) and paternal asthma (OR=2.67, 95% Cl 1.42–5.02), and male sex (OR=1.81, 95% Cl 1.17–2.81). Children from social classes 5 and 6 or with unemployed parents (OR=2.32, 95% Cl 1.22–4.44) were significantly more likely to have asthma than children in social classes 1 and 2. There was no significant association between having polio vaccination (OR=2.48, 95% Cl 0.83–7.41), hepatitis B vaccination (OR=0.66, 95% Cl 0.42–1.04) or measles/mumps/rubella vaccination (OR=1.43, 95% Cl 0.85–2.41) and asthma. Conclusions : This study has confirmed the associations of family history and lower socio‐economic status with current asthma in 7–9 year old children. The role of vaccinations requires further research.

No abstract

This review considers the issues involved in measuring the community prevalence of asthma, particularly in the context of international comparisons. We argue that there is no gold standard definition for measuring asthma prevalence, and discuss the currently available methods of case ascertainment. Prevalence studies, if they are to be generalizable, need to involve large sample sizes with high response rates. This necessitates methods that are simple, inexpensive and practicable, but also as sensitive and specific for asthma as possible. We discuss some of the issues that are specific to comparisons of asthma prevalence between diverse populations, and suggest that large surveys using written or video questionnaires of self reported symptoms validated in all of the target populations are the method of choice.Key words: asthma, bronchial hyperreactivity, epidemiology, prevalence, questionnaires.It could be argued that asthma epidemiology is at the stage cancer epidemiology was 30 years ago, when an international study compared cancer incidence across the continents of the world.' The striking differences in incidence that were found in this study gave rise to a number of hypotheses about possible causes of the international patterns, some of which were subsequently confirmed. Hundreds of asthma prevalence studies have been carried out in numerous parts of the world but international comparisons between countries have for the most part been impossible because the studies have not used common methods, or common definitions of asthma. In order to investigate the underlying causes of asthma, international comparisons of prevalence analogous to those previously conducted for cancer incidence are vital, and are now underway. There have so far been a very small number of studies that have used common protocols to compare prevalence between ~ountries.2,~

No abstract

No abstract