1. |
- Bjerg, Anders, 1982, et al.
(författare)
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Family history of asthma and atopy: in-depth analyses of the impact on asthma and wheeze in 7- to 8-year-old children.
- 2007
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Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 1098-4275 .- 0031-4005. ; 120:4, s. 741-8
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Development of asthma in children is influenced by interactions between genetic and environmental factors. It is unclear whether paternal or maternal histories of disease confer different risks. Previous population-based studies have not stratified analyses by child gender and sensitization status. Our aim was to study in detail the hereditary component of childhood asthma. METHODS: A population-based cohort of 3430 (97% of invited) 7- to 8-year-old school children participated in an expanded International Study of Asthma and Allergy in Childhood survey, and two thirds were skin-prick tested. Heredity was defined as a family history of (1) asthma and (2) atopy (allergic rhinitis or eczema). Multivariate analyses corrected for known risk factors for asthma. RESULTS: At ages 7 to 8, prevalence of asthma was 5.3% among the children and 9.0% among the parents. In children without parental asthma or parental atopy, the prevalence of asthma was 2.8%. Corrected for parental asthma, parental atopy was a weak but significant risk factor. There were minor differences in the impact of parental disease between sensitized and nonsensitized children and between boys and girls. CONCLUSIONS: As risk factors for childhood asthma, there were major differences between parental asthma and parental atopy. Sibling asthma was only a marker of parental disease. Interactions between parental disease and the child's allergic sensitization or gender were not statistically significant. Asthma in both parents conferred a multiplicative risk, whereas the effect of parental atopy was additive, however limited. Asthma and atopy, despite their causal relationship, are separate entities and could be inherited differently. This large, population-based, and well-characterized cohort study does not confirm parent-of-origin effects found in previous studies.
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2. |
- Ekerljung, Linda, 1979, et al.
(författare)
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FinEsS-Stockholm and the Stockholm adult asthma study
- 2008
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Ingår i: The clinical respiratory journal. - 1752-6981. ; 22 Suppl 1, s. 127-128
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Forskningsöversikt (refereegranskat)abstract
- Abstract Two major studies on asthma and respiratory symptoms are presently in progress in Stockholm. The FinEsS-studies has been ongoing since 1996, with a follow-up study preformed in 2006 and a new cohort selected in 2007. The FinEsS studies focus on prevalence and incidence of asthma and respiratory symptoms in a general population. Clinical follow-up surveys will also target COPD. Further aims include remission and relapse of disease and symptoms and their determinants. The Stockholm adult Asthma Study (SaAS) began in the spring of 2007 and data is being collected presently. The SaAS study focus on the medical care and medication given to asthmatics in Stockholm, and the study population consists of asthmatics found in the two Swedish cohort studies.
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4. |
- Gerdtham, Ulf, et al.
(författare)
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Factors affecting chronic obstructive pulmonary disease (COPD)-related costs: a multivariate analysis of a Swedish COPD cohort.
- 2009
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Ingår i: The European journal of health economics : HEPAC : health economics in prevention and care. - : Springer Science and Business Media LLC. - 1618-7598 .- 1618-7601. ; 10:2, s. 217-26
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Tidskriftsartikel (refereegranskat)abstract
- Chronic obstructive pulmonary disease (COPD) is an increasing public health problem, generating considerable costs. The objective of this study was to identify factors affecting COPD-related costs. A cohort of 179 subjects with COPD was interviewed over the telephone on four occasions about their annual use of COPD-related resources. The data set and explanatory variables were analysed by means of multivariate regression techniques for six different types of cost: societal (or total), direct (health care) and indirect (productivity), and three subcomponents of direct costs-hospitalisation, outpatient and medication. Poor lung function, dyspnoea and asthma were independently associated with higher costs. Poor lung function (severity of COPD) significantly increased all six examined cost types. Dyspnoea (breathing problems) also increased costs, though to a varying extent. The presence of reported asthma increased total, direct, outpatient and medication costs. Poor lung function and, to a lesser extent, extent of dyspnoea and concomitant asthma, were all strongly associated with higher COPD-related costs. Strong efforts should be made to prevent the progression of COPD and its symptoms.
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6. |
- Hedlund, Ulf, et al.
(författare)
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Occupational exposure to dust, gases and fumes, a family history of asthma and impaired respiratory health
- 2008
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Ingår i: Scandinavian Journal of Work Environment & Health. - Helsinki : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 34:5, s. 381-386
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Tidskriftsartikel (refereegranskat)abstract
- Objectives This study assessed the impact of occupational exposure to dust, gases, and fumes on respiratory symptoms, obstructive lung diseases, or the use of asthma medication among persons with and without a family history of asthma. Methods A population-based cohort was followed for 10 years. This study included all 1739 men and 1594 women occupationally active at the first survey. Exposure and respiratory health were assessed from questionnaires. Multiple logistic regression was used to estimate the effects in relation to occupational groups, with age, gender, and smoking habits as possible confounders, using both cross-sectional and longitudinal analyses. The susceptibility to impaired respiratory health was determined from a family history of asthma. Results A family history of asthma was reported by 27% of the men and 34% of the women. Both occupational exposure and a family history of asthma were associated with impaired respiratory health. The etiologic fractions showed that up to about 70% of the symptoms could be explained by a family history of asthma among those exposed to low levels of air pollutants, as well as among those with high exposure. However, high exposure contributed up to 35% of the symptoms both among those with and among those without a family history of asthma. The study indicates that the relative risk of occupational exposure to pollutants is similar for both persons with and those without a family history of asthma. Conclusions The relative risk for impaired respiratory health after exposure to occupational air pollutants seems to be similar for persons with and those without a susceptibility to impaired respiratory health.
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7. |
- Jansson, Sven-Arne, et al.
(författare)
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The economic consequences of asthma among adults in Sweden.
- 2007
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Ingår i: Respiratory medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 101:11, s. 2263-70
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Asthma is a common disease in most countries. The objective of this study was to estimate the societal costs for subjects with asthma. METHODS: Telephone interviews regarding resource utilization were made in a representative sample of 115 randomly selected subjects with asthma derived from a large population study of obstructive airway diseases. Direct and indirect costs were measured, and the costs were also transformed with the estimated prevalence of asthma in Sweden. RESULTS: Average annual costs were SEK 15919 (USD 1592; EUR 1768) per subject with asthma in the ages between 25 and 56 years. The direct and indirect costs were SEK 4931 (31.0%) and SEK 10988 (69.0%), respectively, and were highly dependent of age and disease severity. Assuming that the prevalence is representative for Sweden as a whole, the asthmatics would amount to 226000 in the ages between 25 and 56 years, corresponding to an overall prevalence in Sweden of 6-7%. The total costs of asthma for the society amounted thus to SEK 3.7 billion in these ages. CONCLUSIONS: The total costs of asthma for the society could be estimated at 3.7 billion SEK in the age range of 25-56 years, and thus approximately twice as high in the whole population of Sweden. The costs were strongly dependent on disease severity and increasing age.
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8. |
- Juusela, Maria, et al.
(författare)
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Bronchial hyperresponsiveness in a population of north Finland with no previous diagnosis of asthma or chronic bronchitis assessed with histamine and methacholine tests.
- 2008
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Ingår i: International journal of circumpolar health. - : Informa UK Limited. - 1239-9736 .- 2242-3982. ; 67:4, s. 308-17
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To assess the prevalence of bronchial hyperresponsiveness (BHR) in a population of north Finland among subjects with no previous diagnosis of asthma or chronic bronchitis by using histamine and methacholine challenges. The agreement between the methods was also evaluated. STUDY DESIGN: An epidemiological study assessing the prevalence of BHR measured with 2 direct dosimetric challenge methods. METHODS; Seventy-nine randomly selected subjects (21-73 years) were studied; 67% had respiratory or allergic symptoms. The baseline spirometry was normal or showed mild obstruction. Bronchial challenges to methacholine and histamine were performed on each subject in a randomized order. Provocative doses inducing the decrease of FEV1 by 15% and 20% (PD15FEV1 and PD20FEV1) and dose response ratios (DDR) were calculated for both tests. RESULTS; BHR with the methacholine test (PD20FEV1 < or = 2.6 mg) was found in 20% and with the histamine test (PD15FEV1 < or = 1.6 mg) in 28% of subjects; the agreement was 80% (kappa 0.45; 95% CI 0.23-0.68). In staging the severity of BHR the methods had a good agreement (weighted kappa 0.64; CI 95% 0.46-0.82). Prevalence of BHR fulfilling the criteria of the both methods was 14%. CONCLUSIONS: The findings suggest that the prevalence of BHR in the population of north Finland with no previous diagnosis of asthma or chronic bronchitis is at least 14%, probably around 20%, assessed by histamine and methacholine challenge methods. The methods have a good agreement to be used for classifying the severity of BHR.
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10. |
- Kainu, Annette, et al.
(författare)
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Responses of FEV6, FVC, and FET to inhaled bronchodilator in the adult general population.
- 2009
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Ingår i: Respiratory research. - : Springer Science and Business Media LLC. - 1465-993X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The assessment of bronchodilator-induced change in forced vital capacity (FVC) is dependent on forced expiratory time (FET) in subjects with airflow limitation. Limited information is available on the concurrent responses of FVC, forced expiratory volume in six seconds (FEV6), and FET in the bronchodilation test among patients with obstructive airways disease or in the general population. The aim of this study was to assess the changes in FEV6, FVC, and FET, and their relationships in a standardized bronchodilation test in the general population. METHODS: We studied bronchodilation response in a general adult population sample of 628 individuals (260 men, 368 women) with flow-volume spirometry. The largest FVC, the corresponding FET and the largest FEV6 both at the baseline and after 0.4 mg of inhaled salbutamol were selected for analysis. RESULTS: After administration of salbutamol FEV6 decreased on average -13.4 (95% CI -22.3 to -4.5) ml or -0.2% (-0.4% to 0.0%) from the baseline. The 95th percentile of change in FEV6 was 169.1 ml and 5.0%. FVC decreased on average -42.8 (-52.4 to -33.3) ml or -1.0% (-1.2% to -0.7%). Concurrently FET changed on average -0.2 (-0.4 to 0.0) seconds or 0.4% (-1.4% to 2.3%). There were four subjects with an increase of FVC over 12% and only one of these was associated with prolonged FET after salbutamol. Changes in FEV6 and FVC were more frequently positive in subjects with reduced FEV1/FVC in baseline spirometry. CONCLUSION: In general adult population, both FEV6 and FVC tended to decrease, but FET remained almost unchanged, in the bronchodilation test. However, those subjects with signs of airflow limitation at the baseline showed frequently some increase of FEV6 and FVC in the bronchodilation test without change in FET. We suggest that FEV6 could be used in assessment of bronchodilation response in lieu of FVC removing the need for regulation of FET during bronchodilation testing.
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11. |
- Lindberg, A, et al.
(författare)
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The Obstructive Lung Disease in Northern Sweden Chronic Obstructive Pulmonary Disease Study: design, the first year participation and mortality
- 2008
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Ingår i: The clinical respiratory journal. - 1752-6981. ; 22 Suppl 1, s. 64-71
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Most epidemiological data on chronic obstructive pulmonary disease (COPD) are cross-sectional, and the longitudinal course of disease on population bases is incompletely described. AIM: To describe an epidemiological study designed to follow the longitudinal course of disease in chronic obstructive lung disease, COPD, including co-morbidity and mortality and further, to evaluate the impact of COPD on quality of life and health economics. MATERIALS AND METHODS: From the Obstructive Lung Disease in Northern Sweden studies database cohorts I-IV, all subjects with COPD according to the Global Initiative for Chronic Obstructive Lung Disease spirometric criteria, FEV(1)/FVC < 0.70 (n = 993), were identified together with a similar size age- and gender-matched control group. The study population was invited to a yearly examination starting in year 2005. The examinations included structured interview, spirometry with reversibility testing, oxygen saturation and health-related quality of life questionnaires. RESULTS: On the first year, 83% of the population was examined, and the subjects unable to attend the examination were interviewed by telephone. Altogether, 91% of the original study population participated (95% of all subjects were alive at the end of the first year). Mortality was significantly higher among subjects with COPD, 5.1%, compared with controls, 3.0% (P = 0.018). CONCLUSION: The study design including cases of COPD representative of COPD by disease severity in the general population and a similar sized control group, together with a high participation rate in the first study year, creates excellent conditions for evaluating the impact of COPD on population bases, and to follow the longitudinal course of disease in COPD.
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12. |
- Lundbäck, Bo, 1948, et al.
(författare)
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A 20-year follow-up of a population study-based COPD cohort-report from the obstructive lung disease in Northern Sweden studies.
- 2009
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Ingår i: COPD: Journal of Chronic Obstructive Pulmonary Disease. - : Informa UK Limited. - 1541-2563 .- 1541-2555. ; 6:4, s. 263-71
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Tidskriftsartikel (refereegranskat)abstract
- Mortality and other long-term outcomes of COPD from epidemiological studies of cohorts based on the general population are still rare. In contrast, data from follow-ups of patients from hospitals and general practices are more common and demonstrate often a 5-year mortality of about 50% and even higher. The aim was to study 20-year outcomes, mainly mortality, in a COPD cohort derived from a population study. The Obstructive Lung Disease in Northern Sweden (OLIN) Study's first postal survey was performed in 1985, and 5698 subjects (86%) responded. A stratified sample of symptomatic subjects and controls was invited to clinical examinations including lung function tests in 1986, 1506 (91%) of the invited participated and 266 subjects fulfilled the GOLD criteria of COPD. All alive and possible to trace had participated at least at two follow-up examinations. Of the 266 subjects with COPD 46% were still alive after 20 years. The proportion of survived among subjects with severe and very severe COPD at entry was 19%. Death was significantly related to age, male sex, disease severity and concomitant ischemic heart disease or cardiac failure at entry. Socioeconomic status (manual workers) was significant in the univariate analysis, but failed to reach statistical significance in the multivariate model. The annual decline in FEV(1) among survivors was low to normal. Long-term follow-ups of subjects with COPD derived from population studies provide data reflecting the course of COPD in society better than follow-ups of hospital recruited patients, who represent the top of the iceberg. Surprisingly many with severe COPD were still alive after 20 years.
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13. |
- Lundbäck, Bo, 1948, et al.
(författare)
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Asthma control over 3 years in a real-life study.
- 2009
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Ingår i: Respiratory medicine. - : Elsevier BV. - 1532-3064 .- 0954-6111. ; 103:3, s. 348-55
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Tidskriftsartikel (refereegranskat)abstract
- This was a 3-year "real-life" study, during which patients' medication was increased and decreased to achieve sustained asthma control. Patients (282) were randomised to receive treatment with SAL 50microg, FP 250microg, or SFC 50/250microg via a Diskustrade mark inhaler, bid. A 12-month double-blind period was followed by a 2-year open phase. The physician increased or decreased patients' medication to achieve and maintain asthma control at regular clinical assessments using criteria based on the asthma treatment guidelines. On completion 73% (168/229) of the subjects were receiving SFC to maintain control of their asthma, compared with 21% (49/229) receiving FP and 5% (12/229) receiving SAL. Odds ratio for requiring increased treatment were 2.66 (p=0.002) for patients initially randomised to FP and 9.38 (p<0.0001) SAL, compared with SFC. Time until 25% of patients first required an increase in study medication was 6months for patients initially treated with SAL compared to 12months for FP and 21months for SFC. Symptoms and use of rescue medication improved first, followed rapidly by PEF with the greatest improvements occurring over the first year. Airway hyperresponsiveness continued to improve throughout the study. The majority of patients achieved and maintained control of asthma over a 3-year period with physician-driven medication changes. Patients treated with SFC were more likely to achieve control than patients treated with FP or SAL alone. Continuing improvements in airway hyperresponsiveness indicate the importance of maintaining treatment after clinical control of symptoms and lung function are achieved.
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14. |
- Lundbäck, Bo, 1948, et al.
(författare)
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General population-based cohorts for studies of lung health in adults in Sweden
- 2008
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Ingår i: Clinical Respiratory Journal. - Oxford : Blackwell Publishing. - 1752-6981 .- 1752-699X. ; 2:Suppl 1, s. 2-9
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological population-based studies about lung health in Sweden have mostly been focused on obstructive airway diseases. From the 1960s to the 1980s, the epidemiological studies were cross-sectional, aiming at the study of the prevalence of asthma, chronic bronchitis and respiratory symptoms and their associations with mainly demographic data. With the exception of highly stratified samples, for instance the men born on 1913 in Gothenburg and cohorts of occupational groups or work places, general population-based cohorts for studies of lung health in adults are still not very common. Two large-scale studies of lung health have been in progress in Sweden for more than 20 years; the Obstructive Lung Disease in Northern Sweden (OLIN) Studies, which started in 1985, and the Swedish part of European Community Respiratory Health Survey (ECRHS) since 1989 with the follow-Lip survey labelled Respirator), Health in Northern Europe (RHINE). During the 1990s the comparative studies between Finland, Estonia and Sweden (The FinEsS Studies) started. These and other studies will be reviewed in the following exemplifying change of aims and study designs over time as well as change of focus of risk factors under study.
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15. |
- Lötvall, Jan, 1956, et al.
(författare)
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West Sweden Asthma Study: Prevalence trends over the last 18 years argue no recent increase in asthma.
- 2009
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Ingår i: Respiratory research. - : Springer Science and Business Media LLC. - 1465-993X. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Asthma prevalence has increased over the last fifty years, but the more recent changes have not been conclusively determined. Studies in children indicate that a plateau in the prevalence of asthma may have been reached, but this has not yet been confirmed in adults. Epidemiological studies have suggested that the prevalence of asthma in adults is approximately 7-10% in different parts of the western world. We have now performed a large-scale epidemiological evaluation of the prevalence of asthma and respiratory symptoms in adults between the ages of 16-75 in West Sweden. Thirty thousand randomly chosen individuals were sent a detailed questionnaire focusing on asthma and respiratory symptoms, as well possible risk factors. Sixty-two percent of the contacted individuals responded to the questionnaire. Asthma prevalence, defined as asthma diagnosed by a physician, was 8.3%. Moreover, the prevalence of respiratory symptoms was lower compared to previous studies. The most common respiratory symptom was any wheeze (16.6%) followed by sputum production (13.3%). In comparison with studies performed 18 years ago, the prevalence of asthma has not increased, and the prevalence of most respiratory symptoms has decreased. Therefore, our data argues that the continued increase in asthma prevalence that has been observed over the last half century is over.
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16. |
- Rönmark, Eva, 1953, et al.
(författare)
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Major increase in allergic sensitization in schoolchildren from 1996 to 2006 in northern Sweden.
- 2009
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Ingår i: The Journal of allergy and clinical immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 124:2
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Time trends for allergic sensitization are poorly known. OBJECTIVE: To compare the trends in prevalence of allergic sensitization and associated risk factors in children. METHODS: Two cohorts of children (age 7-8 years) were invited for skin prick tests (SPTs) 10 years apart, 1996 and 2006. The participation rates were 2148 (88%) and 1700 (90%), respectively. The methods were identical, and 10 common airborne allergens were used. An expanded International Study of Allergy and Asthma in Children questionnaire about symptoms and possible risk factors for allergic conditions was completed by the parents. RESULTS: The prevalence of any positive SPT increased from 21% in 1996 to 30% in 2006 (P < .001). The pattern of sensitization remained similar, and sensitization to cat was most common both years, 13% and 19%, respectively. Sensitization to mites and mold was uncommon in both surveys. A family history of allergy was a significant risk factor for a positive SPT both years (odds ratio, 1.7). Factors that in 1996 had a protective effect, such as rural living and having several siblings, had lost this effect in 2006. The prevalence of most risk factors remained similar, but respiratory infections and smoking among parents decreased significantly. During the same period, there was no significant increase in the prevalence of current wheeze (11.9% to 12.4%, P = .636) or symptoms of rhinitis or eczema. CONCLUSION: The prevalence of allergic sensitization increased significantly from 1996 to 2006, whereas no increase in clinical symptoms was found. The parallel decrease in parental smoking and respiratory infections indicate a different influence of environmental factors on allergic sensitization and clinical symptoms, respectively.
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17. |
- Rönmark, Eva, 1953, et al.
(författare)
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Outcome and severity of adult onset asthma--report from the obstructive lung disease in northern Sweden studies (OLIN).
- 2007
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Ingår i: Respiratory medicine. - : Elsevier BV. - 0954-6111. ; 101:11, s. 2370-7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Studies of longitudinal changes in severity and the long-term outcome of asthma in epidemiological settings are uncommon. AIM: To assess the outcome of incident asthma in a cohort of subjects who developed asthma after the age of 20 years. METHODS: This is a prospective study of the outcome of 309 subjects with incident asthma being included in a case-referent study based on all adults aged 20-60 years living in three municipalities/towns in Northern Sweden. The subjects fulfilled the criteria for incident asthma defined as onset of symptoms common in asthma within 12 months prior to the study and a verified bronchial variability. In 2003, 250 (81%) of the subjects with asthma were re-examined with structured interview, lung-function test and methacholine test. RESULTS: At follow-up, 237 (95%) subjects still had an active asthma, i.e. they had symptoms or used asthma medicines. Among those with active asthma, 65% were using inhaled cortico-steroids. Severity grading (GINA 2000) showed that 21% had mild intermittent asthma, 30% mild persistent, 44% moderate persistent, and 5% severe asthma, contrasting to 75% with moderate or severe asthma at entry. Higher age, higher BMI and low lung function were associated with greater asthma severity. Twelve subjects (5%) were in remission. Predictors for remission were non-sensitisation and a normal lung function. Age, sex, BMI, and smoking habits were not significantly different between those in remission and those not. CONCLUSIONS: Remission of adult onset asthma was low. Severity of asthma changed considerably over time, however, the overall change was towards a milder disease probably as a result of treatment.
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18. |
- Rönmark, Erik P, 1981, et al.
(författare)
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Large scale questionnaire survey on respiratory health in Sweden: effects of late- and non-response.
- 2009
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Ingår i: Respiratory medicine. - : Elsevier BV. - 1532-3064 .- 0954-6111. ; 103:12, s. 1807-15
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Participation rates in epidemiologic studies conducted with postal questionnaires have steadily declined since 1970s. This can lead to an increased risk for selection bias. The aim of this study was to examine cause and effect of non-response in a large cross sectional study assessing respiratory health in western Sweden. METHODS: The study sample was 29,218. The response rate to the initial postal questionnaire was 33%. The response rates to subsequent postal reminders were 15%, 7% and 7% of eligible participants totalling a participation of 62%. Of those who did not respond to the postal survey, a random sample of 400 subjects were identified and contacted for interview by telephone. RESULTS: Non-responders did not differ significantly in prevalence of airway diseases or symptoms when compared with responders. Male sex, young age and smokers were underestimated among non-responders. No clear trends in prevalence of respiratory symptoms and report of asthma were found with delayed response to the postal survey. The proportion of smokers and men increased with increasing number of reminders. Letters reminding subjects about the study did increase the participation rate but did not alter the risk estimates. CONCLUSION: We conclude that with a response rate of 62%, our estimate of disease and symptom prevalence was not biased in this Swedish population. However, smoking was underestimated. No general trend for late-responders was seen and therefore we conclude that extrapolation of results to non-responders is not possible in our study. Causes of non-response were mainly due to circumstantial factors.
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19. |
- Rönmark, Eva, et al.
(författare)
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The Obstructive Lung Disease in Northern Sweden (OLIN) longitudinal paediatric study I : the first 10 years
- 2008
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Ingår i: Clinical Respiratory Journal. - Oxford : Blackwell Publishing. - 1752-6981 .- 1752-699X. ; 2:Suppl 1, s. 26-33
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Tidskriftsartikel (refereegranskat)abstract
- Background: Prospective studies of asthma and allergic conditions based oil the general population are scare.Aim: To summarize the methods and main results from a prospective study among school children.Methods: In 1996, a cohort of 3525 children aged 7/8 years in Northern Sweden were invited to a questionnaire survey using an expanded ISAAC protocol, and 97% participated. The cohort has been followed up yearly with high participation rate. Skin prick tests were conducted 1996, 2000 and 2006/2007. Allergens in dust from homes and schools have been analyzed. Sub samples have participated in interviews, lung function tests, bronchial hyper reactivity test, and analyses of IgE and IgG antibodies in serum.Results: The prevalence of asthma was 6% at age 7-8 years and increased by age. The incidence of physician-diagnosed asthma after the age of 7-8 years was around 1/100/year. The prevalence of positive skin prick test increased from 21% at age 7-8 to 30% at age 11-12 years. Remission of allergic sensitization was rare, while asthma remission was 5% yearly. The main risk factor for asthma and allergic sensitization increased in importance with increasing age. Allergic and non-allergic asthma had different risk factor pattern. Environmental risk factors decreased in impact after the age of 7. Avoidance of pets at home did not protect from asthma or allergic sensitization.Conclusion: The study includes important sources of data for further longitudinal analyses that will contribute to the understanding of the development and the nature of asthma and allergic sensitization.
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