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Asthma Prevalence (asthma + prevalence)

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Selected Abstracts

Is the prevalence of asthma declining?

ALLERGY, Issue 2 2010
Systematic review of epidemiological studies
To cite this article: Anandan C, Nurmatov U, van Schayck OCP, Sheikh A. Is the prevalence of asthma declining? Systematic review of epidemiological studies. Allergy 2010; 65: 152,167. Abstract Asthma prevalence has increased very considerably in recent decades such that it is now one of the commonest chronic disorders in the world. Recent evidence from epidemiological studies, however, suggests that the prevalence of asthma may now be declining in many parts of the world, which, if true is important for health service planning and also because this offers the possibility of generating and testing new aetiological hypotheses. Our objective was to determine whether the prevalence of asthma is declining worldwide. We undertook a systematic search of EMBASE, Medline, Web of Science and Google Scholar, for high quality reports of cohort studies, repeat cross-sectional studies and analyses of routine healthcare datasets to examine international trends in asthma prevalence in children and adults for the period 1990,2008. There were 48 full reports of studies that satisfied our inclusion criteria. The large volume of data identified clearly indicate that there are, at present, no overall signs of a declining trend in asthma prevalence; on the contrary, asthma prevalence is in many parts of the world still increasing. The reductions in emergency healthcare utilization being reported in some economically developed countries most probably reflect improvements in quality of care. There remain major gaps in the literature on asthma trends in relation to Africa and parts of Asia. There is no overall global downward trend in the prevalence of asthma. Healthcare planners will for the foreseeable future, therefore, need to continue with high levels of anticipated expenditure in relation to provision of asthma care. [source]

Work-related stress, inability to relax after work and risk of adult asthma: a population-based cohort study

ALLERGY, Issue 10 2010
A. Loerbroks
To cite this article: Loerbroks A, Gadinger MC, Bosch JA, Stürmer T, Amelang M. Work-related stress, inability to relax after work and risk of adult asthma: a population-based cohort study. Allergy 2010; 65: 1298,1305. Abstract Background:, There is an extensive literature linking stressful work conditions to adverse health outcomes. Notwithstanding, the relationship with asthma has not been examined, although various other measures of psychological stress have been associated with asthma. Therefore, we aimed to investigate the relation between work stress and asthma prevalence and incidence. Methods:, We used data from a population-based cohort study (n = 5114 at baseline in 1992,1995 and n = 4010 at follow-up in 2002/2003). Asthma was measured by self-reports. Two scales that assessed psychologically adverse work conditions were extracted from a list of work-condition items by factor analysis (these scales were termed ,work stress' and ,inability to relax after work'). For each scale, the derived score was employed both as continuous z -score and as categorized variable in analyses. Associations with asthma were estimated by prevalence ratios (PRs) and risk ratios (RRs) using Poisson regression with a log-link function adjusting for demographics, health-related lifestyles, body mass index and family history of asthma. Analyses were restricted to those in employment (n = 3341). Results:, Work stress and inability to relax z -scores were positively associated with asthma prevalence (PR = 1.15, 95%CI = 0.97, 1.36 and PR = 1.43, 95%CI = 1.12, 1.83, respectively). Prospective analyses using z -scores showed that for each 1 standard deviation increase in work stress and inability to relax, the risk of asthma increased by approximately 40% (RR for work stress = 1.46, 95%CI = 1.06, 2.00; RR for inability to relax = 1.39, 95%CI = 1.01, 1.91). Similar patterns of associations were observed in analyses of categorized exposures. Conclusions:, This is the first study to show a cross-sectional and longitudinal association of work stress with asthma. [source]

Is the prevalence of asthma declining?

Ozone exposure and its influence on the worsening of childhood asthma

ALLERGY, Issue 7 2009
S. I. V. Sousa
Background:, It is well documented that high levels of many airborne pollutants can adversely affect many systems of the human body. The aim of this study was to evaluate the specific impact of ozone (O3) on the worsening of childhood asthma, comparing children living at regions with high and low O3 concentrations (reference site) without the confounding effects of other pollutants. Methods:, Pollutant concentrations were monitored and data concerning asthma prevalence were collected through a questionnaire. The studied population consisted of 478 children aged 6,13 years old enrolled in four schools of the municipalities where monitoring was performed. Remote sites were identified with very low concentrations of nitrogen dioxide and volatile organic compounds and high concentrations of O3. Results:, The prevalence of wheeze for lifetime period and in the past year was 15.9% and 6.3%, respectively. Asthmatic children were identified when dyspnoea and wheezing were simultaneously mentioned in the absence of upper respiratory infections; according to that, the lifetime prevalence of asthmatic symptoms at the remote sites was 7.1%. The comparison with other previous studies was difficult because the criteria for analysis are not conveniently established. Conclusion:, The prevalence of childhood asthmatic symptoms was about 4% higher at the high O3 site than at the low O3 site. [source]

Stabilization of asthma prevalence among adolescents and increase among schoolchildren (ISAAC phases I and III) in Spain,

ALLERGY, Issue 12 2004
L. García-Marcos
Background:, Most studies show a steep increase in asthma prevalence in the last decades, although few studies had applied the same methodology. Recent reports point out the possibility that the epidemic has come to an end. We have studied the prevalence of asthma in a very large sample of children, repeating the study eight years apart. Methods:, Repeated cross-sectional studies using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol in a sample of Spanish schoolchildren 6,7 (parent-reported) and 13,14 (self-reported) years old in 1994,95 (phase I) and 2002,2003 (phase III). The number of participants was 42 417 in phase I and 42 813 in phase III. The participation rate was over 87% (13,14 years) and 70% (6,7 years). Results:, The prevalence of wheezing in the previous year in children aged 13,14 years was 9.0 and 9.3% for boys and 9.6 and 9.2% for girls for phases I and III, respectively. Children 6,7 years of age showed a substantial increase in wheezing in the previous year (7.0 and 10.7% for boys and 5.3 and 8.2% for girls). Other symptoms and severity indexes followed the same patterns. Conclusions:, In the last 8 years, the prevalence of asthma has not changed in 13,14-year-old Spanish children but has increased substantially in 6,7-year olds. [source]

Effects of changing risk factors on increasing asthma prevalence in southern Taiwan

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 1 2003
Hui-chun A. Tsuang
Summary The study sought to identify factors with consistent relationships with the prevalence of asthma and postulate causes for the increasing prevalence. Reduplication of prevalence surveys was conducted among children of similar ages (6,12 years) from the same area (Tainan City, Taiwan). A total of 7523 primary school children from 1993 and 7224 from 1997 participated in the study. The reported prevalence of diagnosed asthma increased from 6.46% in 1993 to 8.45% in 1997 (relative risk 1.31, 95% CI 1.16, 1.47). Among all environment- and heredity-related factors examined, only four showed consistent relationships with childhood asthma, and all appeared to be a related hereditary condition. Dander allergy is the only factor that increased correspondingly with the prevalence of childhood asthma; therefore, it seems to be the most likely key factor responsible for the increasing trend. The investigation of the interactive effects imposed by the environment- (dander exposure) and heredity-related (atopic sensitisation) factors are recommended for further studies. [source]

Childhood asthma prevalence: the impact of the 1997 National Health Interview Survey redesign

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 4 2001
Lj Akinbami
No abstract is available for this article. [source]

Asthma in late adolescence , farm childhood is protective and the prevalence increase has levelled off

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2010
Göran Wennergren
Wennergren G, Ekerljung L, Alm B, Eriksson J, Lötvall J, Lundbäck B. Asthma in late adolescence , farm childhood is protective and the prevalence increase has levelled off. Pediatr Allergy Immunol 2010: 21: 806,813. © 2010 John Wiley & Sons A/S While the prevalence of and risk factors for asthma in childhood have been studied extensively, the data for late adolescence are more sparse. The aim of this study was to provide up-to-date information on the prevalence of and risk factors for asthma in the transitional period between childhood and adulthood. A secondary aim was to analyze whether the increase in asthma prevalence has levelled off. A large-scale, detailed postal questionnaire focusing on asthma and respiratory symptoms, as well as possible risk factors, was mailed to 30 000 randomly selected subjects aged 16,75 in Gothenburg and the surrounding western Sweden region. The present analyses are based on the responses from 1261 subjects aged 16,20 (560 men and 701 women). The prevalence of physician-diagnosed asthma was 9.5%, while 9.6% reported the use of asthma medicine. In the multivariate analysis, the strongest risk factors for physician-diagnosed asthma and other asthma variables were heredity for asthma and heredity for allergy, particularly if they occurred together. Growing up on a farm significantly reduced the prevalence of physician-diagnosed asthma and the likelihood of using asthma medication, OR 0.1 (95% CI 0.02,0.95). Smoking increased the risk of recurrent wheeze, long-standing cough, and sputum production. In conclusion, the prevalence of physician-diagnosed asthma and the use of asthma medication in the 16- to 20-yr age group support the notion that the increase in asthma prevalence seen between the 1950s and the 1990s has now levelled off. In line with the hygiene hypothesis, a farm childhood significantly reduced the likelihood of asthma. The adverse effects of smoking could already be seen at this young age. [source]

Changing prevalence of asthma in Taiwanese adolescents: two surveys 6 years apart

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 2 2005
Yung-Ling Lee
This study compared the prevalence of asthma among Taiwanese adolescents with individual-level risk factors and municipal-level air pollution and meteorology data to determine whether changes in these factors could explain the observed change in prevalence. We conducted two national surveys of respiratory illness and symptoms in Taiwanese middle-school students in 1995,96 and 2001. The effects of personal and environmental factors were assessed and temporal changes of outdoor monitoring data were also compared with asthma prevalence difference. A total of 44,104 children from the 1995,96 survey and 11,048 children from the 2001 survey attended schools located within 1 km of 22 monitoring stations. Lifetime prevalences of physician-diagnosed and questionnaire-determined asthma increased during this period. After adjustment for potential risk factors, the prevalence differences were statistically unchanged. Although parental education level contributed most, changes in investigated personal and environmental factors might not explain the observed changes in asthma prevalence. Municipalities with higher temperature increase were significantly associated with prevalence difference in questionnaire-determined asthma. We concluded that correlates of the investigated individual-level factors, which have changed over time, still underlie changes in asthma prevalence. Increasing temperature might be the main reason for the rising trends of asthma in Taiwanese adolescents. [source]

Seasonal variability in exercise test responses in Ghana

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 4 2002
Emmanuel O. D. Addo-Yobo
Exercise-induced bronchospasm (EIB) is widely used in epidemiological studies to investigate the prevalence of asthma. We aimed to determine seasonal variations in the prevalence of EIB in Ghanaian school children from urban-rich (UR), urban-poor (UP), and rural (R) schools. We have previously reported the prevalence of EIB in 9,16-year-old children to be 3.1% in the dry season, with UR children having a significantly higher prevalence of both EIB and atopy compared to UP or R children. In the current study, the prevalence of EIB was assessed in the same 1,095 children in the wet season (5 months following the initial study) using the same methodology. Exercise provocation consisted of free running outdoors for 6 min. In the wet season, 17/1,095 children [mean 1.55%, 95% confidence interval (CI): 0.91,2.47] had a positive response to exercise, compared to our previous report of 34 children (mean 3.1%, 95% CI: 2.15,4.32) with EIB in the dry season (dry vs. wet season, difference 1.55, 95% CI: 0.41,2.69). The proportion of children with a positive response to exercise in the UR school fell from 4.2% (25/599) to 1.3% (8/599) (difference 2.9, 95% CI: 1.2,4.5). In the wet season, there was no difference in the prevalence of EIB among the UR, UP, and R children. Only five of 1,095 subjects (mean 0.5%, 95% CI: 0.15,1.07) demonstrated EIB in both seasons. In conclusion, although exercise challenge remains a useful tool for determining asthma prevalence in epidemiological studies, seasonal variations in the pattern of responses may occur and the results should be interpreted with caution. [source]

Chronic disease risk in central New York dairy farmers: Results from a large health survey 1989,1999

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2005
Paul L. Jenkins PhD
Abstract Background The agricultural workplace presents a variety of health and safety hazards; it is unknown whether farm work may be a risk factor for certain chronic diseases. Methods The health survey data from a large rural population in central New York were used from two studies (1989, 1999) to assess both 1999 prevalence and 10-year incidence of self-reported diabetes, heart disease, hypercholesterolemia, and hypertension among farm (predominantly dairy) and non-farm residents. The 1999 asthma prevalence was also assessed. Results Multiple logistic regression models for 1999 prevalence found statistically significant protective effects of farming for hypertension (OR,=,0.83, P,=,0.0105) and hypercholesterolemia (OR,=,0.853, P,=,0.0522). Non-significant results were seen for heart disease (OR,=,0.67, P,=,0.128) and diabetes (OR,=,0.856, P,=,0.1358). The model for 1999 asthma prevalence showed a significantly elevated risk for farming (OR,=,1.542, P,=,0.0004). Logistic models created for the 10-year incidence of hypertension, hypercholesterolemia, diabetes, and heart disease did not show a significant effect for farming. Conclusions The protective effect of farming observed for the 1999 prevalence of hypertension and hypercholesterolemia was not seen for the 10-year incidence of these diseases. Am. J. Ind. Med. 47:20,26, 2005. © 2004 Wiley-Liss, Inc. [source]

Trends in asthma prevalence and severity in Omani schoolchildren: Comparison between ISAAC phases I and III

RESPIROLOGY, Issue 5 2008
Omar A. AL-RAWAS
Background and objective: This study evaluated changes in the prevalence of asthma symptoms and asthma severity in Omani school children over time. Methods: Two cross-sectional surveys, in 1995 and 2001, were conducted as part of the International Study of Asthma and Allergies in Children on Omani schoolchildren in two different age groups (6,7 and 13,14 years). Results: There were 7067 children surveyed in 1995 (3893 in the younger and 3174 in the older group) and 7879 in 2001 (4126 in the younger and 3753 in the older group). Over the 6 years there was a significant increase in the prevalence of current wheeze ,any wheeze during the past 12 months' (from 7.1% to 8.4%; P = 0.035) in the younger group with no significant change in asthma diagnosis (10.5% vs 10.6%) or any other asthma symptoms. In the older group, all asthma symptoms remained unchanged except speech-limiting wheeze which declined from 4.0% to 2.8% (P = 0.007). In both surveys, more than 60% of current wheezers reported severe asthma symptoms, while only 60% of these reported a diagnosis of asthma. Conclusion: The prevalence of both asthma and severe asthma remains high among Omani children. There is significant ,under-diagnosis' and/or ,under-treatment' of asthmatic children which requires urgent evaluation and intervention. [source]

An inverse correlation between estimated tuberculosis notification rates and asthma symptoms

RESPIROLOGY, Issue 2 2002
PHILIPPA SHIRTCLIFFE
Background: A recent ecological analysis demonstrated a strong inverse relationship between tuberculosis notification rates and the prevalence of asthma symptoms in 13,14-year-old children as obtained from the International Study of Asthma and Allergies in Childhood (ISAAC). However, the analysis was confined to the 23 countries in which the tuberculosis notification rates were considered to be of sufficient validity. Methods: A similar analysis was performed using estimated tuberculosis incidence rates obtained from the World Health Organization Global Tuberculosis Programme and asthma symptom prevalence data from ISAAC for both the 6,7 and 13,14 years age groups in 38 and 55 countries, respectively. Results: For the 6,7-year-old children, there was a significant inverse relationship between estimated tuberculosis incidence and the prevalence of key asthma symptoms. However, in the 13,14 year age group, a significant inverse relationship was only demonstrated for ,asthma ever'. Conclusion: The present study extends the inverse relationship between tuberculosis rates and asthma prevalence to the 6,7-year-old age group and suggests that the association, if causal, may be stronger at this younger age. [source]

Birth order, atopy, and symptoms of allergy and asthma among inner-city children attending Head Start in New York City

CLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2008
M. S. Perzanowski
Summary Background In past research, children with older siblings were more likely than others to wheeze at age 2 years, but less likely by age 6 years. Higher infection transmission and a down-regulated allergic immune response as a result of these infections, respectively, were suggested as the causes. However, in a study of children aged 0,3 years in a low-income urban community in New York City, USA, with high asthma prevalence, we observed no birth-order effect. Objective To evaluate the association between birth order and atopy and respiratory symptoms in 4-year-old children attending Head Start programs in NYC. Methods Respiratory symptoms were assessed by questionnaire for 1005 children (mean age 4.0 years) living in high asthma prevalence neighbourhoods. Serum was collected from a subgroup of the children (n=494) and specific IgE responses to dust mite, cockroach, mouse, and cat allergens were measured. Results Prevalence of specific IgE (0.35 IU/mL) did not differ significantly among first (35%), second (35%), and later-born children (28%) (P=0.23). Increasing birth order was associated with increasing prevalence of respiratory symptoms in the prior year, including wheeze (first 20%, second 27%, third or later 35%; P<0.001), being awakened at night by cough (28%, 33%, 38%; P=0.005), emergency department visits (14%, 17%, 21%; P=0.02) and hospitalizations for difficulty breathing (6.1%, 6.6%, 10%; P=0.04). The associations of birth order with respiratory symptoms were statistically significant only for the non-seroatopic children and those without an asthmatic parent. Conclusions Non-seroatopic children with older siblings were more likely than those without older siblings to have respiratory symptoms at age 4 years. Although the stability of these associations over time remains to be determined, the differences in findings between this study and our previous NYC birth cohort study suggest that patterns of asthma development may vary even among low-income populations within the same city. [source]