Changes in the relationship between asthma and associated risk factors over fifty years (original) (raw)
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Determinants of the Incidence of Childhood Asthma: A Two-Stage Case-Control Study
American Journal of Epidemiology, 2008
Extensive literature exists on potential risk factors for childhood asthma. To the authors' knowledge, no investigators have yet attempted to disentangle the effects of those determinants within a single study setting. The authors aimed to evaluate the independent effects of 47 potential determinants (from the prenatal, perinatal, and childhood periods) of asthma development in children within the first 10 years of life. From a Canadian birth cohort of 26,265 children (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002), a 2-stage case-control study was conducted. In the first stage, 20 controls per case were selected from 3 administrative databases. In the second stage, selected mothers were mailed questionnaires for assessment of additional determinants. Increased risks of childhood asthma were found for 1 previous diagnosis of bronchopulmonary disease and atopic dermatitis in the child, oxygen administration after birth, prescription of antibiotics within the first 6 months of life, male gender, asthma during pregnancy, use of antibiotics during pregnancy, maternal receipt of social aid, paternal asthma, and asthma in siblings. Protective effects included use of intranasal corticosteroids during pregnancy, having a wood-burning fireplace, having pets in the home prior to the index date, breastfeeding, and day-care attendance. This study allowed the authors to identify, within a single setting, the most influential determinants of childhood asthma among 47 predictors assessed for the prenatal, perinatal, and childhood periods.
1998
Some children develop asthma and other atopic diseases, others asthma without atopic diseases. To better understand secular trends, we estimated the relative increase in asthma in children with (atopy related asthma) and without (non-atopy related asthma) other atopic diseases (eczema or hay fever) in two samples of school children born, 1965-1975 (n = 1674) and 1978-1988 (n = 2188). By analysing the samples as historical cohorts, age-specific prevalence rates were estimated and incidence rates were calculated (number of new cases by 1000 personyears under risk). Cox regression was used to estimate the relative risk (RR) of asthma by year of birth. The point prevalence of asthma was 1.9% (95% CI: 1.4-2.4) in the 1965-1975 cohort and 4.6% (95% CI: 3.8-5.4) in the 1978-1988 cohort for three-year old children, and remained fairly constant throughout childhood. The age-specific prevalence of non-atopy related asthma increased relatively more from 1965-1975 to 1978-1988 compared to atopy related asthma. The age-specific incidence rates of asthma showed that the RRs comparing the two cohorts tended at all ages to be highest for nonatopy related asthma. The relative risks of non-atopy related asthma by gender and birth cohort, showed that the effect of cohort was higher for non-atopy related asthma, aRR: 4.0 (95% CI: 2.5-6.5), than for atopy-related asthma aRR: 2.0 (95% CI: 1.3-3.2). Children without other atopic diseases have a higher relative risk of being diagnosed with asthma than children with other atopic diseases across all ages comparing two samples of school children born 1965-1975 and 1978-1988.
Factors in childhood as predictors of asthma in adult life
BMJ, 1994
Objective-To determine which factors measured in childhood predict asthma in adult life. Design-Prospective study over 25 years of a birth cohort initially studied at the age of7. Setting-Tasmania, Australia. Subjects-1494 men and women surveyed in 1991-3 when aged 29 to 32 (75%/ ofa random stratified sample from the 1968 Tasmanian asthma survey of children born in 1961 and at school in Tasmania). Main outcome measures-Selfreported asthma or wheezy breathing in the previous 12 months (current asthma). Results-Of the subjects with asthma or wheezy breathing by the age of7, as reported by their parents 25 6% (190/741) reported current asthma as an adult compared with 108%/o (81/753) of subjects without parent reported childhood asthma (P<0.001). Factors measured at the age of 7 that independently predicted current asthma as an adult were being female (odds ratio 1-57; 95%/ confidence interval 1419 to 2.08); having a history of eczema (1.45; 1-04 to 2.03); having a low mild forced expiratory flow rate (interquartile odds ratio 1-40; 1.15 to 1.71); having a mother or father with a history of asthma (1-74 (1-23 to 2.47) and 1'68 (1.18 to 2.38) respectively); and having childhood asthma (1.59; 1 10 to 2.29) and, if so, having the first attack after the age of2 (1.66; 1I17 to 2.36) or having had more than 10 attacks (1.70; 1.17 to2 248). Conclusion-Children with asthma reported by their parents in 1968 were more likely than not to be free of symptoms as adults. The subjects who had more severe asthma (especially if it developed after the age of 2 and was associated with reduced expiratory flow), were female, or had parents who had asthma were at an increased risk of having asthma as an adult. These findings have implications for the treatment and prognosis ofchildhood asthma, targeting preventive and educational strategies, and understanding the onset ofasthma in adult life. separately on subjects with and without childhood BMJ VOLUME 309
Journal of Epidemiology, 2013
Background: In settings in which diseases wax and wane, there is a need to measure disease dynamics in longitudinal studies. Traditional measures of disease occurrence (eg, cumulative incidence) do not address change or stability or are limited to stable cohorts (eg, incidence) and may thus lead to erroneous conclusions. To illustrate how different measures can be used to detect disease dynamics, we investigated sex differences in the occurrence of asthma and wheezing, using a population-based study cohort that covered the first 18 years of life. Methods: In the Isle of Wight birth cohort (n = 1456), prevalence, incidence, cumulative incidence, positive and negative transitions, and remission were determined at ages 1 or 2, 4, 10, and 18 years. Latent transition analysis was used to simultaneously identify classes of asthma and wheezing (related phenotypes) and characterize transition probabilities over time. Trajectory analysis was used to characterize the natural history of asthma and wheezing. Results: Regarding time-specific changes, positive and negative transition probabilities were more informative than other measures of associations because they revealed a sex switchover in asthma prevalence (P < 0.05). Transition probabilities were able to identify the origin of a sex-specific dynamic; in particular, prior wheezing transitioned to asthma at age 18 years among girls but not among boys. In comparison with latent transition analysis, trajectory analysis did not directly identify a switchover in prevalence among boys and girls. Conclusions: In longitudinal analyses, transition analyses that impose minimal restrictions on data are needed in order to produce appropriate information on disease dynamics.
Variations in the prevalence of childhood asthma and wheeze in MeDALL cohorts in Europe
ERJ open research, 2017
While there is evidence for variations in prevalence rates of childhood wheeze and asthma between countries, longitudinal, individual-level data are needed to understand these differences. The aim of this study was to examine variations in prevalence rates of childhood asthma, wheeze and wheeze with asthma in Europe. We analysed datasets from 10 MeDALL (Mechanisms of the Development of ALLergy) cohorts in eight countries, representing 26 663 children, to calculate prevalence rates of wheeze and asthma by child age and wheeze with asthma at age 4 years. Harmonised variables included outcomes parent-reported wheeze and parent-reported doctor-diagnosed asthma, and covariates maternal education, parental smoking, pets, parental asthma, doctor-diagnosed allergic rhinitis, doctor-diagnosed eczema and wheeze severity. At age 4 years, asthma prevalence varied from 1.72% in Germany to 13.48% in England and the prevalence of wheeze varied from 9.82% in Greece to 55.37% in Spain. Adjusted esti...
Risk Factors and Predictive Clinical Scores for Asthma Exacerbations in Childhood
Chest, 2010
D isease exacerbations account for the majority of asthma-related costs. Among children living in the United States,. 4 million asthma exacerbations occur each year, resulting in approximately 700,000 ED visits, 205,000 hospital admissions, and 200 deaths per year. 1,2 Without including prescriptions, costs related to pediatric asthma exacerbations accounted for 9.8billion(63.29.8 billion (63.2%) of the estimated 9.8billion(63.215.5 billion total asthma costs in the United States in 2002. 3 According to guidelines for the diagnosis and management of asthma from the National Heart, Lung and Blood Institute (NHLBI), two or more exacerbations requiring oral steroids per year place children in the persistent category, represent suboptimal control, and increase morbidity and mortality. 4 The prevalence of pediatric asthma exacerbations varies widely by ethnicity. Among Hispanic children living in the United States, the prevalence ranges from 2.9% in Mexicans to 11.8% in Puerto Ricans, and the rate of ED visits is 14.1% for Hispanics vs 10.8% for non-Hispanic whites. 2 The prevalence of childhood asthma in Costa Rica, a Hispanic American country, is among the highest in the world. 5 During phase 3 of the International Study for Asthma and Allergies in Childhood (ISAAC) study, the reported current prevalence of asthma was 34.8% for 6-to 7-year-olds and 25.5% for 13-to 14-year-olds; with 9.7% and 6.7%, respectively, reporting more than four exacerbations a year. Little is known, however, about risk factors for asthma Background: Asthma is a major public health problem that affects millions of children worldwide, and exacerbations account for most of its morbidity and costs. Primary-care providers lack efficient tools to identify children at high risk for exacerbations. We aimed to construct a clinical score to help providers to identify such children. Methods: Our main outcome was severe asthma exacerbation, which was defi ned as any hospitalization, urgent visit, or systemic steroid course for asthma in the previous year, in children. A clinical score, consisting of a checklist questionnaire made up of 17 yes-no questions regarding asthma symptoms, use of medications and health-care services, and history, was built and validated in a cross-sectional study of Costa Rican children with asthma. It was then evaluated using data from the Childhood Asthma Management Program (CAMP), a longitudinal trial cohort of North American children. Results: Compared with children at average risk for an exacerbation in the Costa Rican validation set, the odds of an exacerbation among children in the low-risk (OR, 0.2; 95% CI, 0.1-0.4) and high-risk (OR, 5.4; 95% CI, 1.5-19.2) score categories were signifi cantly reduced and increased, respectively. In CAMP, the hazard ratios for an exacerbation after 1-year follow-up in the low-risk and high-risk groups were 0.6 (95% CI, 0.5-0.7) and 1.9 (95% CI, 1.4-2.4), respectively, with similar results at 2 years. Conclusions: The proposed Asthma Exacerbation Clinical Score is simple to use and effective at identifying children at high and low risk for asthma exacerbations. The tool can easily be used in primary-care settings.
The Importance of Family History in Asthma during the First 27 Years of Life
American Journal of Respiratory and Critical Care Medicine, 2013
References 1. Weibel ER, Gomez DM. A principle for counting tissue structures on random sections. J Appl Physiol 1962;17:343-348. 2. Ochs M, Nyengaard JR, Jung A, Knudsen L, Voigt M, Wahlers T, Richter J, Gundersen HJG. The number of alveoli in the human lung. Am J Respir Crit Care Med 2004;169:120-124. 3. Hansen JE, Ampaya EP, Bryant GH, Navin JJ. Branching pattern of airways and airspaces of a single human terminal bronchiole. J Appl Physiol 1975;38:983-989. 4. Weibel ER. It takes more than cells to make a good lung. Am J Respir Crit Care Med 2013;187:342-346. 5. Haefeli-Bleuer B, Weibel ER. Morphometry of the human pulmonary acinus. Anat Rec 1988;220:401-414. 6. Swan AJ, Tawhai MH. Evidence for minimal oxygen heterogeneity in the healthy human pulmonary acinus.
The Lancet, 2006
Background Data for trends in prevalence of asthma, allergic rhinoconjunctivitis, and eczema over time are scarce. We repeated the International Study of Asthma and Allergies in Childhood (ISAAC) at least 5 years after Phase One, to examine changes in the prevalence of symptoms of these disorders. Methods For the ISAAC Phase Three study, between 2002 and 2003, we did a cross-sectional questionnaire survey of 193 404 children aged 6-7 years from 66 centres in 37 countries, and 304 679 children aged 13-14 years from 106 centres in 56 countries, chosen from a random sample of schools in a defined geographical area. Findings Phase Three was completed a mean of 7 years after Phase One. Most centres showed a change in prevalence of 1 or more SE for at least one disorder, with increases being twice as common as decreases, and increases being more common in the 6-7 year age-group than in the 13-14 year age-group, and at most levels of mean prevalence. An exception was asthma symptoms in the older age-group, in which decreases were more common at high prevalence. For both age-groups, more centres showed increases in all three disorders more often than showing decreases, but most centres had mixed changes. Interpretation The rise in prevalence of symptoms in many centres is concerning, but the absence of increases in prevalence of asthma symptoms for centres with existing high prevalence in the older age-group is reassuring. The divergent trends in prevalence of symptoms of allergic diseases form the basis for further research into the causes of such disorders.