Respiratory symptoms and atopy in Aberdeen schoolchildren: evidence from two surveys 25 years apart.

Abstract

Objective-To estimate changes in the prevalence of respiratory symptoms and the reported diagnoses of asthma, eczema, and hay fever in primary school children in Aberdeen between 1964 and 1989.Design-Determination of incidence prevalence and prevalence from survey data.Setting-Aberdeen, Scotland. Participants-2743 primary school children (aged 8-13) from 1964 and 3942 from 1989.Main outcome measures -Survey data on whether, according to the parent or guardian, the child wheezed or was troubled with shortness of breath; the number of episodes of breathlessness in the past year; and whether asthma, eczema, or hay fever had ever been diagnosed.Results-Questionnaires were completed by the parents of 2510 children in 1964 and 3403 children in 1989. The prevalence of wheeze rose from 10-4% in 1964 to 19-8% in 1989, and the prevalence of episodes of shortness of breath increased from 5-4% to 10-0%. In both surveys wheeze and shortness of breath were more prevalent in boys than in girls. The reported diagnosis of asthma rose from 4-1% to 10-2%, hay fever from 3-2% to 11-9%, and eczema from 5.3% to 12%. The proportion of boys suffering from eczema rose from 47-7% to 60-0%. Hay fever showed a similar increase, from 49-4% to 60-1%, in boys over the 25 year period. Though the parents of a higher proportion ofchildren with wheeze were aware of the diagnosis of asthma in 1989, because ofthe increased prevalence ofwheeze the absolute number ofparents ofwheezy children who were not aware of a diagnosis of asthma increased from 7-4% to 9-6% of the population studied.Conclusion-The higher diagnosis rate for asthma is due not simply to changes in diagnostic fashion but reflects an increase over the past 25 years in the prevalence of respiratory symptoms, which in turn may reflect a more general change in the prevalence of atopy, the increase in which was particularly noticeable in boys. This increase explains some of the increase in hospital admission rates for children with asthma.

Apparent but not real increase in asthma prevalence during the 1990s

“…The rates of increase are substantial and equivalent to a y5% increase per annum in the number of subjects affected, but they are similar to those reported in other studies in which the same population has undergone repeated investigation [1][2][3][4][5]. The rates of increase are more striking in subjects aged v30 yrs.…”

“…An increase in disease prevalence has been supported by a number of studies in which the same population has been surveyed more than once at intervals of ¡25 yrs [1][2][3][4]. Observed rates of change for those affected within UK populations have been w6% per annum for 8-13-yr-old children [1,2], 7% per annum for university entrants [3], and 8% per annum for 12-yr-old children [4]. These findings were based on questionnaire responses, and so may have been influenced by increased awareness of asthmatic symptoms and an increased likelihood of reporting them.…”

Prevalence of respiratory symptoms, bronchial hyperresponsiveness and atopy among adults: west and east Germany

“…BRABÄCK et al [15], in a comparison of atopic sensitization and respiratory symptoms among Swedish and Polish school children, reported that children living in urban Sweden, as compared to urban Poland, were more frequently diagnosed as being asthmatic by a doctor, and had higher prevalences of positive skin-prick test reactions against mugwort, timothy, birch and cat. Several studies have indicated a rising trend in atopic diseases and asthma over time both in children [16][17][18][19][20][21] and adolescents [2,22,23]. Most authors suggest that this is not simply due to improved diagnostic trends.…”

Prevalência de asma em adolescentes na cidade de Fortaleza, CE

“…(2,3) Genetic factors, although important, probably do not explain that increase, which has been attributed to the interaction between genetic and environmental factors. Environmental factors seem to have greater relevance in the determination of the symptoms of asthma, (4,5) the etiology of which remains poorly understood, despite a considerable amount of research in the area.…”

“…(6,19) The questionnaires were completed by the students themselves, in the classroom and in the presence of the principal researcher or one the research assistants, duly trained by the formerthey received a manual developed by the ISAAC Fortaleza is located on a coastal flat, immediately below the equator, between latitude 3°30' and latitude 4°30', at an altitude of 15.49 m above sea level. It has an area of 4,667.8 km 2 and had a population of 2,431,415 inhabitants in 2000. (14) The annual mean temperature ranges from 26 to 27°C, and the relative humidity is approximately 82%.…”