Asthma, type-1 allergy and related conditions in 7- and 8-year-old children in Northern Sweden

Department of Occupational Health, National Institute for Working Life, Umeå, Sweden.
Respiratory Medicine (Impact Factor: 3.09). 03/1998; 92(2):316-24. DOI: 10.1016/S0954-6111(98)90115-9
Source: PubMed


As a first step in an intervention study of asthma and allergic diseases among school children, a cross-sectional study was performed during Winter 1996 in three towns (Kiruna, Luleå and Piteå) in the northernmost province of Sweden, Norrbotten. The cross-sectional study aimed to measure the prevalence of asthma, type-1 allergy and allergic diseases in order to make it possible to measure the incidence of the diseases, conditions and symptoms related to the diseases. Another aim was to perform a screening for possible risk factors. All children enrolled in the first and second classes at school, 7 and 8 years old, were invited to take part in this study. The ISAAC questionnaire with added questions about symptoms, morbidity, heredity and environment was distributed by the schools to the parents. The response rate was 97%, and 3431 completed questionnaires were returned. The children in two of the municipalities were also invited to skin test, and 2149 (88%) were tested with 10 common airborne allergens. The results showed that 7% of the children were currently using or had used asthma medicines during the last 12 months. Six percent had asthma diagnosed by a physician, and 4% were using inhaled corticosteroids. The prevalence of wheezing during the last 12 months was 12%, rhinitis without colds 14%, and eczema 27%, while 21% had a positive skin test. The respiratory symptoms and conditions were significantly greater in boys and, further, they were most prevalent in Kiruna in the very north, though not significantly. Type-1 allergy and asthma had different risk factor patterns. The main risk factors for asthma were a family history of asthma (OR = 3.2) followed by past or present house dampness (OR = 1.9), male sex (OR = 1.7) and a smoking mother (OR = 1.6). In Kiruna, when none of these three risk factors were present, none of the children had asthma, but when all three were present, 38% of these children were using asthma medicines.

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    • "The OLIN paediatric study I, is a longitudinal study about asthma, rhinitis, eczema, and allergic sensitization among schoolchildren in Northern Sweden. The overall aims and methods have previously been described in detail [13]. The parents of all 3,525 children aged 7 and 8 years in three municipalities, enrolled in the first and second grades in 1996, were invited to complete a questionnaire. "
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    ABSTRACT: Because of shifts in the gender ratio and incidence and remission rates of asthma during the teen ages, the methodology of incidence studies among teenagers is important, i.e. if the time intervals between surveys are too long, the incident cases might not be properly identified. The aim was to study the impact of study design on the incidence rates of asthma and wheeze during the teen ages. In a study about asthma and allergic diseases within the OLIN studies (Obstructive Lung Disease in northern Sweden), a cohort of school children (n = 3,430) was followed annually by questionnaire from age 8 yrs. In the endpoint survey (age 18 yrs) 2,582 (75% of original responders) participated. Incident cases from age 12-18 yrs were identified by two methods: annual questionnaire reports (AR) and baseline-endpoint surveys only (BE). The cumulative incidence of asthma and wheeze was significantly higher based on AR compared to BE. Compared to the incidence rates based on all the annual surveys, the calculated average annual rates based on BE were in general lower both among the boys and among the girls. There were no differences between boys and girls in incidence rates of asthma or wheeze during the early teen years. However, from the age of 15 years, the annual incidence rates were significantly or borderline significantly higher among girls than boys. At onset, the additional cases of current asthma identified by AR had significantly less severe asthma than those identified in BE (p < 0.02). the size of the incidence of asthma and wheeze during the teen ages was influenced by study design. By using the conventional prospective study design with longer follow-up time, the incidence was underestimated.
    01/2012; 2(1):1. DOI:10.1186/2045-7022-2-1
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    • "The BMHE study reported prevalence in 4-year-old children of approximately 9% among boys and 6% among girls [13]. A number of other studies have reported prevalence among 6–8 year old children with estimates similar to our 6-year estimates [3,29]. "
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    ABSTRACT: There are few studies on age and sex-specific asthma prevalence in the age range 1-6 years. The purpose of this report was to estimate age and sex specific asthma prevalence in preschool children and to analyse the influence of possible demographic and geographic determinants. All 70 allergen avoidance day-care centres and 140 matched ordinary day-care centres across Sweden were sampled. The parents of all 8,757 children attending these day-care centres received the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire, supplemented with questions on medical treatment, physician assessed asthma diagnosis, and other asthma related questions. The response rate was 68%. The age specific asthma prevalence, adjusted for the underlying municipality population size, was among boys 9.7% at age 1, 11.1% at age 2, 11.4 at age 3, 10.5 at age 4, 8.7 at age 5, and 6.4 at age 6. The corresponding proportions among girls were 8.9%, 9.9%, 9.8%, 8.8%, 7.0%, and 5.0%, on average 9.6% for boys and 8.2% for girls, altogether 8.9%. In addition to age and sex the prevalence increased by municipality population density, a proxy for degree of urbanisation. Moreover, there was a remaining weak geographical gradient with increasing prevalence towards the north and the west. The age-specific asthma prevalence was curvilinear with a peak around age 3 and somewhat higher for boys than for girls. The asthma prevalence increased in a slowly accelerating pace by municipality population density as a proxy for degree of urbanisation.
    BMC Public Health 09/2009; 9(1):303. DOI:10.1186/1471-2458-9-303 · 2.26 Impact Factor
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    • "In an international study of 12-year old children in 1994, questionnaire-reported asthma-prevalence was found to range from 16.8 % in New Zealand, 12 % in Wales and 11.5 % in South Africa to only 4% in Sweden [16]. Support of these data and that questionnaires may not grossly over-estimate prevalence is found by another questionnaire study from Sweden in 1989 where a frequency of 5.1 % in 9000 rural children of age between 4–14 years was reported [17], whereas in 1988 the percentage of 7–8-year-old children in Northern Sweden with asthma diagnosed by a physician was found to be 6% [18]. A previous Swedish cumulative incidence investigation was reported for a defined region in 1992, where up to the age of 12–14 years, 5.3 % of an n = 1654 birth-year cohort were seen at the University Hospital with a clinically confirmed diagnosis of asthma [19]. "
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    ABSTRACT: Childhood asthma has risen dramatically not only in the western societies and now forms a major and still increasing public health problem. The aims of this study were to follow up at the age of ten the patterns of asthma symptoms and associations among children with a clinically diagnosed asthma in a sizeable urban-rural community and to in compare them with demographic controls using a standardised questionnaire. In a defined region in Sweden with a population of about 150,000 inhabitants, all children (n = 2,104) born in 1990 were recorded. At the age of seven all primary care and hospital records of the 1,752 children still living in the community were examined, and a group of children (n = 191) was defined with a well-documented and medically confirmed asthma diagnosis. At the age of ten, 86 % of these cases (n = 158) and controls (n = 171) completed an ISAAC questionnaire concerning asthma history, symptoms and related conditions. Different types of asthma symptoms were highly and significantly over-represented in the cases. Reported asthma heredity was significantly higher among the cases. No significant difference in reported allergic rhinitis or eczema as a child was found between cases and controls. No significant difference concerning social factors or environmental exposure was found between case and controls. Among the control group 4.7 % of the parents reported that their child actually had asthma. These are likely to be new asthma cases between the age of seven and ten and give an estimated asthma prevalence rate at the age of ten of 15.1 % in the studied cohort. A combination of medical verified asthma diagnosis through medical records and the use of self-reported symptom through the ISAAC questionnaire seem to be valid and reliable measures to follow-up childhood asthma in the local community. The asthma prevalence at the age of ten in the studied birth cohort is considerably higher than previous reports for Sweden. Both the high prevalence figure and allowing the three-year lag phase for further settling of events in the community point at the complementary roles of both hospital and primary care in the comprehensive coverage and control of childhood asthma in the community.
    BMC Family Practice 05/2005; 6(1):16. DOI:10.1186/1471-2296-6-16 · 1.67 Impact Factor
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