RESUMO
INTRODUCTION AND OBJECTIVES: Wheezing (RW) infants with a positive asthma predictive index (API+) have a lower lung function as measured by forced expiratory techniques. Tidal flow-volume loops (TFVL) are easy to perform in infants, and sedation is not necessary. MATERIALS AND METHODS: A total of 216 wheezing infants were successfully measured, and 183 of them were followed for over a year. TFVL loops were classified into one of three categories depending of their geometric shape (symmetric, convex, and concave). Respiratory rate (Rr), presence of API+, and the number of exacerbations during the following year were also recorded. RESULTS: Children with concave loops had more exacerbations in the following year (ORâ¯=â¯6.8 [IC95% 3.33;13.91]). Infants APIâ¯+â¯were also significantly more related to concave loops (ORâ¯=â¯10.02 [IC 95% 4.53; 22.15]). Rr was higher in infants with concave loops (44+/-15.5 vs. 36.6 +/-12.6; pâ¯<â¯0.01). CONCLUSION: Infants with a concave TFVL have a higher probability of experiencing exacerbations in the following year, and are at a higher risk of suffering asthma.
Assuntos
Asma/diagnóstico , Asma/fisiopatologia , Testes de Função Respiratória/métodos , Sons Respiratórios/diagnóstico , Sons Respiratórios/fisiopatologia , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Volume de Ventilação PulmonarRESUMO
The diagnosis of asthma is currently based on clinical history, physical examination and lung function, and to date, there are no accurate objective tests either to confirm the diagnosis or to discriminate between different types of asthma. This consensus exercise reviews the state of the art in asthma diagnosis to identify opportunities for future investment based on the likelihood of their successful development, potential for widespread adoption and their perceived impact on asthma patients. Using a two-stage e-Delphi process and a summarizing workshop, a group of European asthma experts including health professionals, researchers, people with asthma and industry representatives ranked the potential impact of research investment in each technique or tool for asthma diagnosis and monitoring. After a systematic review of the literature, 21 statements were extracted and were subject of the two-stage Delphi process. Eleven statements were scored 3 or more and were further discussed and ranked in a face-to-face workshop. The three most important diagnostic/predictive tools ranked were as follows: "New biological markers of asthma (eg genomics, proteomics and metabolomics) as a tool for diagnosis and/or monitoring," "Prediction of future asthma in preschool children with reasonable accuracy" and "Tools to measure volatile organic compounds (VOCs) in exhaled breath."
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Asma/diagnóstico , Prioridades em Saúde , Pesquisa , Biomarcadores , Testes Respiratórios , Consenso , Europa (Continente) , Humanos , Metabolômica/métodos , Prognóstico , Testes de Função RespiratóriaRESUMO
BACKGROUND: There is a conflictive position if some foods and Mediterranean diet (MedDiet) consumed by the mother during pregnancy and by the child during the first years of life can be protective for current wheezing, rhinitis and dermatitis at preschool age. METHODS: Questionnaires of epidemiological factors and food intake by the mother during pregnancy and later by the child were filled in by parents in two surveys at two different time points (1.5 yrs and 4 yrs of life) in 1000 preschoolers. RESULTS: The prevalences of current wheezing, rhinitis and dermatitis were 18.8%, 10.4%, and 17.2%, respectively. After multiple logistic analysis children who were low fruit consumers (never/occasionally) and high fast-food consumers (≥3 times/week) had a higher risk for current wheezing; while intermediate consumption of meat (1 or 2 times/week) and low of pasta by mothers in pregnancy were protected. For current rhinitis, low fruit consumer children were at higher risk; while those consuming meat <3 times/week were protected. For current dermatitis, high fast food consumption by mothers in pregnancy; and low or high consumption of fruit, and high of potatoes in children were associated to higher prevalence. Children consuming fast food >1 times/week were protected for dermatitis. MedDiet adherence by mother and child did not remain a protective factor for any outcome. CONCLUSION: Low consumption of fruits and high of meat by the child, and high consumption of potatoes and pasta by the mother had a negative effect on wheezing, rhinitis or dermatitis; while fast food consumption was inconsistent.
Assuntos
Dermatite/epidemiologia , Dieta Mediterrânea , Sons Respiratórios , Rinite/epidemiologia , Adulto , Pré-Escolar , Feminino , Alimentos , Humanos , Lactente , Masculino , Exposição Materna/efeitos adversos , Pessoa de Meia-Idade , Exposição Paterna/efeitos adversos , Gravidez , Prevalência , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: Wheezing is a very common problem in infants in the first months of life. The objective of this study is to identify risk factors that may be acted upon in order to modify the evolution of recurrent wheezing in the first months of life, and to develop a model based on certain factors associated to recurrent wheezing in nursing infants capable of predicting the probability of developing recurrent wheezing in the first year of life. METHODS: The sample was drawn from a cross-sectional, multicentre, descriptive epidemiological study based on the general population. A total of 1164 children were studied, corresponding to a questionnaire response rate of 71%. The questionnaire of the Estudio Internacional de Sibilancias en Lactantes (EISL) was used. Multiple logistic regression analysis was used to estimate the probability of developing recurrent wheezing and to quantify the contribution of each individual variable in the presence of the rest. RESULTS: Infants presenting eczema and attending nursery school, with a mother who has asthma, smoked during the third trimester of pregnancy, and did not consume a Mediterranean diet during pregnancy were found to have a probability of 79.7% of developing recurrent wheezing in the first year of life. In contrast, infants with none of these factors were seen to have a probability of only 4.1% of developing recurrent wheezing in the first year of life. These results in turn varied according to modifications in the risk or protective factors. CONCLUSIONS: The mathematical model estimated the probability of developing recurrent wheezing in infants under one year of age in the province of Salamanca (Spain), according to the risk or protective factors associated to recurrent wheezing to which the infants are or have been exposed.
Assuntos
Asma/epidemiologia , Dermatite Atópica/epidemiologia , Sons Respiratórios/diagnóstico , Asma/diagnóstico , Estudos Transversais , Dieta Mediterrânea , Feminino , Humanos , Imunidade Materno-Adquirida , Lactente , Recém-Nascido , Masculino , Exposição Materna/efeitos adversos , Modelos Teóricos , Gravidez , Prognóstico , Recidiva , Fatores de Risco , Fumar/efeitos adversos , Espanha/epidemiologiaRESUMO
BACKGROUND: Epidemiologic studies suggest a relationship between maternal nutrition during pregnancy and the occurrence of asthma and atopic conditions during childhood. However, individual study results are conflicting. The objective of this meta-analysis was to critically examine the current evidence for an association between nutrition (dietary patterns, food groups, vitamins, or oligo-elements) ingestion during pregnancy and asthma, wheeze, or atopic conditions in childhood. METHODS: The inclusion criteria were as follows: (i) systematic recording of diet during the gestational period and (ii) documentation of asthma, wheezing, eczema, or other atopic disease in the offspring. The primary outcomes were prevalence of asthma or wheeze among the offspring during childhood; and secondary outcomes were prevalence of eczema, allergic rhinitis, or other atopic conditions. RESULTS: We found 120 titles, abstracts, and citations, and 32 studies (29 cohorts) were included in this analysis. Data on vitamins, oligo-elements, food groups, and dietary patterns during pregnancy were collected. A meta-analysis revealed that higher maternal intake of vitamin D [odds ratio (OR) = 0.58, 95% confidence interval (CI) = 0.38-0.88], vitamin E (OR = 0.6, 95% CI = 0.46-0.78), and zinc (OR = 0.62, 95% CI = 0.40-0.97) was associated with lower odds of wheeze during childhood. However, none of these or other nutrients was consistently associated with asthma per se or other atopic conditions. CONCLUSIONS: Current evidence suggests a protective effect of maternal intake of each of three vitamins or nutrients (vitamin D, vitamin E, and zinc) against childhood wheeze but is inconclusive for an effect on asthma or other atopic conditions.
Assuntos
Asma/epidemiologia , Hipersensibilidade Imediata/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Fenômenos Fisiológicos da Nutrição Pré-Natal , Sons Respiratórios/etiologia , Asma/etiologia , Dieta/efeitos adversos , Feminino , Humanos , Hipersensibilidade Imediata/etiologia , Razão de Chances , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Prevalência , Fatores de RiscoRESUMO
BACKGROUND: Infections by respiratory syncytial virus (RSV) are more severe in patients with cystic fibrosis (CF), and many CF units use palivizumab as prophylaxis; however, information about palivizumab efficacy in CF patients is almost lacking. METHODS: A literature search up to December 2012 on the morbidity of RSV bronchiolitis in CF patients and on the safety and efficacy of palivizumab in those patients was performed. A random-effects meta-analysis was conducted for those studies meeting pre-specified search criteria. Historical controls were allowed. RESULTS: The number of patients who received palivizumab was 354 and the hospital admission rate was 0.018 (95% CI 0.0077-0.048). The corresponding number in the non-treated groups was 463 patients with an admission rate of 0.126 (95% CI 0.086-0.182) (Q=13.9; p<0.001). CONCLUSION: Palivizumab may have a role in the prevention of severe lower airway infection by RSV in CF patients.
Assuntos
Antivirais/uso terapêutico , Fibrose Cística/tratamento farmacológico , Palivizumab/uso terapêutico , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sinciciais Respiratórios/imunologia , Animais , Fibrose Cística/complicações , Hospitalização , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Infecções por Vírus Respiratório Sincicial/etiologiaRESUMO
OBJECTIVES: To determine the prevalence of wheezing during the first year of life in Cantabria, Spain and its associated risk factors. METHODOLOGY: A cross-sectional, multicentre, descriptive epidemiological study was carried out in a representative sample of 958 infants in the first year of life, born in Cantabria. A previously validated and standardised written questionnaire was completed by the parents of infants seen between 12 and 15 months of age in the Primary Care Centres. RESULTS: The prevalence of wheezing was 32.7%. A relationship was found with male gender (OR 1.38, 95%CI [1.05-1.81]), the presence of a sibling (OR 2.43 [1.38-3.98]), attending nursery school (OR 2.40 [1.71-3.35]), exclusive breastfeeding for <3 months (OR 1.47 [1.12-1.93]), a first cold at ≤3 months (OR 2.07 [1.56-2.74]), asthma in siblings (OR 2.17 [1.25-3.77]), parental allergic rhinitis (OR 1.62 [1.10-2.37]) and paracetamol use >1 a week (OR 2.49 [1.31-4.73]), and maternal smoking during pregnancy (OR 2.18 [1.51-3.15]). The prevalence of recurrent wheezing (≥3 episodes) was 14.3%. Significant associations were observed with the male gender (OR 1.79 [1.23-2.60]), attending nursery school (OR 2.92 [1.96-4.35]), first cold at ≤3 months (OR 2.11 [1.46-3.04]), eczema (OR 1.92 [1.21-3.04]), maternal asthma (OR 1.77 [1.00-3.14]), exclusive breastfeeding for <3 months (OR 1.53 [1.06-2.22]), and maternal smoking during pregnancy (OR 1.53 [1.05-2.22]). CONCLUSIONS: One third of the infants experienced wheezing during the first year of life; those who were less exclusively breastfed, attended nursery school, presented eczema, family asthma or allergic rhinitis, and maternal smoking during pregnancy.
Assuntos
Asma/epidemiologia , Sons Respiratórios/etiologia , Fatores Sexuais , Asma/complicações , Aleitamento Materno , Estudos Transversais , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez , Prevalência , Fatores de Risco , Escolas Maternais , Fumar/efeitos adversos , EspanhaRESUMO
BACKGROUND: Asthma exacerbations attended in emergency departments show a marked seasonality in the paediatric age. This seasonal pattern can change from one population to another and the factors involved are poorly understood. OBJECTIVES: To evaluate the association between meteorological factors and schooling with asthma exacerbations in children attended in the paediatric emergency department of a district hospital. METHODS: We conducted a retrospective review of the medical records of children 5-14 years of age attended for asthma exacerbations during a 4-year period (2007-2011). Climatic data were obtained from a weather station located very close to the population studied. The number of asthma exacerbations was correlated to temperature, barometric pressure, relative humidity, rainfall, wind speed, wind distance, solar radiation, water vapour pressure and schooling, using regression analyses. RESULTS: During the study period, 371 children were attended for asthma exacerbations; median age was eight years (IQR: 6-11), and 59% were males. Asthma exacerbations showed a bimodal pattern with peaks in spring and summer. Maximum annual peak occurred in week 39, within 15 days from school beginning after the summer holidays. A regression model with mean temperature, water vapour pressure, relative humidity, maximum wind speed and schooling could explain 98.4% (p<0.001) of monthly asthma exacerbations. CONCLUSIONS: The combination of meteorological factors and schooling could predict asthma exacerbations in children attended in a paediatric emergency department.
Assuntos
Asma/diagnóstico , Conceitos Meteorológicos , Adolescente , Asma/epidemiologia , Criança , Pré-Escolar , Serviços Médicos de Emergência/estatística & dados numéricos , Feminino , Hospitais de Distrito , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Instituições Acadêmicas , Estações do Ano , EspanhaRESUMO
BACKGROUND: Several studies have observed an association between obesity and asthma, but whether or not there is an association with rhinoconjunctivitis or eczema is unclear. AIMS: To examine the relationship between body mass index categories (underweight, overweight and obesity), vigorous physical activity and television viewing and the risk of symptoms of asthma, rhinoconjunctivitis and eczema. METHODS: As part of International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three, parents or guardians of children aged 6-7 years completed written questionnaires about symptoms of asthma, rhinoconjunctivitis and eczema, and several potential risk factors, such as vigorous physical activity and television viewing, and other information such as the child's height and weight. Adolescents aged 13-14 years self-completed the questionnaires on these symptoms and potential risk factors and reported their own height and weight. For 28% of children and 24% of adolescents, the height and weight was objectively measured. RESULTS: A total of 76 164 children aged 6-7 years (from 29 centres and 17 countries) and 201 370 adolescents aged 13-14 years (from 73 centres and 35 countries) provided data meeting the inclusion criteria. There were associations between overweight and obesity, but not underweight, and symptoms of asthma and eczema but not rhinoconjunctivitis. Vigorous physical activity was positively associated with symptoms of asthma, rhinoconjunctivitis and eczema in adolescents, but not children. Viewing television for five or more hours/day was associated with an increased risk of symptoms of asthma, rhinoconjunctivitis and eczema in adolescents and symptoms of asthma in children. CONCLUSIONS AND CLINICAL RELEVANCE: This study has confirmed the association between overweight and obesity and symptoms of asthma. It has extended these observations to include significant associations with symptoms of eczema, but not rhinoconjunctivitis. There are complex relationships between obesity, vigorous physical activity and sedentary behaviour and the symptoms of asthma, rhinoconjunctivitis and eczema in children.
Assuntos
Asma/epidemiologia , Exercício Físico , Obesidade/epidemiologia , Televisão , Adolescente , Asma/etiologia , Índice de Massa Corporal , Criança , Conjuntivite/epidemiologia , Conjuntivite/etiologia , Eczema/epidemiologia , Eczema/etiologia , Feminino , Humanos , Masculino , Obesidade/complicações , Sobrepeso/complicações , Sobrepeso/epidemiologia , Prevalência , Rinite/epidemiologia , Rinite/etiologia , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Classification of respiratory symptoms may help to identify different underlying asthma phenotypes reflecting differences in aetiology and prognosis of wheezing disease among children. OBJECTIVE: To determine childhood asthma phenotypes based on respiratory symptoms from a widely used questionnaire to further classify phenotypes in international settings. METHODS: Between 2000 and 2002 cross-sectional studies were performed in four centres in Spain. Parental questionnaires were used to collect information on allergic diseases in more than 4000 children aged 8-12 years. In addition, objective markers for allergic sensitization and bronchial hyperresponsiveness (BHR) were measured. Latent class analyses (LCA) were applied to identify subgroups of children according to respiratory symptoms, and then the association of these groups with relevant clinical features such as concomitant allergic disease symptoms, atopy and BHR was studied. RESULTS: We found seven classes, one corresponding to healthy children, three classes related to wheeze and three other classes mainly related to congestion and coughed-up phlegm. These tentative phenotypes differed in severity of symptoms and also in clinical correlates such as BHR and allergic sensitization. Atopy was more predominant in the 'wheeze phenotypes' whereas concomitant 'allergic' symptoms were most frequent in two of the 'wheeze phenotypes' and one of the 'cough phenotypes'. CONCLUSIONS: LCA on reported symptoms in a cross-sectional survey allowed different subgroups with meaningful clinical correlates to be defined. It remains to be investigated to what extent these groups also have different aetiologies, prognoses and therapeutic needs.
Assuntos
Asma/diagnóstico , Fenótipo , Sons Respiratórios/diagnóstico , Antiasmáticos/administração & dosagem , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Asma/etiologia , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Sons Respiratórios/efeitos dos fármacos , Sons Respiratórios/etiologia , Fatores de Risco , Espanha , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Dermatophagoides pteronyssinus specific IgE (sIgE) measurement is a major diagnostic test for the detection of sensitization to that allergen. METHODS: To investigate the effect of climate on the seasonal variations of D.pteronyssinus sIgE, we studied the tests performed in an insular population during a 10-year period. The association with meteorological factors was evaluated with multiple regression analyses. RESULTS: Of 24,879 tests performed for D. pteronyssinus sIgE, 16,719 (67.2%) were D. pteronyssinus sIgE positive; 24.5% were tested for asthma and 46.07% for rhinitis. D. pteronyssinus sIgE levels showed a seasonal pattern with an annual peak in November. In the multivariate analyses solar radiation (r = -0.94) and relative humidity (r = 0.86) were independent factors associated with D. pteronyssinus sIgE levels. The resulting model could explain 93% (p < 0.001) of D. pteronyssinus sIgE variability. CONCLUSIONS: Our population showed a seasonal pattern of D. pteronyssinus sIgE explained by relative humidity and solar radiation.
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Antígenos de Dermatophagoides/imunologia , Dermatophagoides pteronyssinus/imunologia , Imunoglobulina E/sangue , Conceitos Meteorológicos , Animais , Asma/imunologia , Humanos , Rinite Alérgica , Rinite Alérgica Perene/imunologia , Estações do Ano , Testes CutâneosRESUMO
BACKGROUND: There is epidemiological evidence that Mediterranean diet exposure is associated with lower asthma prevalence in children. We aimed to summarize the available data and to know whether the Mediterranean setting modifies this association. METHODS: The literature search, up to May 2012, was on epidemiological studies in the general population of children assessing whether adherence to Mediterranean diet (measured as a score) was associated with the prevalence of 'current wheeze'; 'current severe wheeze'; or 'asthma ever'. Odds ratios (OR) of the eight included studies compared the highest tertile of the score with the lowest. Random-effects meta-analyses for the whole group of studies and stratified by Mediterranean setting (centers <100 Km from the Mediterranean coast) were performed. Differences between strata were assessed using the Q test. RESULTS: For 'current wheeze', there was a negative significant association with the highest tertile of Mediterranean diet score (OR 0.85, 95% CI 0.75-0.98; p = 0.02), driven by Mediterranean centers (0.79, 0.66-0.94, p = 0.009), although the difference with the non-Mediterranean centers (0.91, 0.78-1.05, p = 0.18) was not significant. The results for 'current severe wheeze' were as follows: 0.82, 0.55-1.22, p = 0.330 (all); 0.66, 0.48-0.90, p = 0.008 (Mediterranean); and 0.99, 0.79-1.25, p = 0.95 (non-Mediterranean); with the difference between regions being significant. For 'asthma ever', the associations were as follows: 0.86, 0.78-0.95, p = 0.004 (all); 0.86, 0.74-1.01, p = 0.06 (Mediterranean); 0.86, 0.75-0.98; p = 0.027 (non-Mediterranean); with the difference between regions being negligible. CONCLUSIONS: Adherence to the Mediterranean diet tended to be associated with lower occurrence of the three respiratory outcomes. For current and current severe wheeze, the association was mainly driven by the results in Mediterranean populations.
Assuntos
Asma/epidemiologia , Dieta Mediterrânea/estatística & dados numéricos , Animais , Asma/complicações , Criança , Humanos , Prevalência , Sons Respiratórios/etiologia , EspanhaRESUMO
OBJECTIVES: To determine the prevalence of wheezing and its associated risk factors in infants in the first year of life in the province of Salamanca, Spain. METHODS: A multicentre, cross-sectional, descriptive epidemiological study was designed to evaluate a representative sample of 750 infants in the first year of life, born in the province of Salamanca between 1 June 2008 and 30 September 2009. The study was based on a previously validated and standardised written questionnaire administered among the parents of those children seen for control at 12 months of age in any of the Primary Care centres in the province of Salamanca. RESULTS: The recorded wheezing rate was 32.3%. Feeding and sleep were seen to be affected in 46.3% and 80.9% of the wheezing children, respectively, and parent activity was also altered in 39.3% of the cases. A relationship was found between wheezing and nursery attendance (OR: 1.66, 95% confidence interval [1.19-2.31]); weight at birth >3500 g (OR: 1.45 [1.02-2.06]); the presence of eczema at this age (OR: 2.72 [1.75-4.24]); exclusive breastfeeding for <3 months (OR: 1.33 [0.98-1.81]); and maternal smoking during the last three months of pregnancy (OR: 1.60 [0.96-2.68]). The prevalence of recurrent wheezing (defined as three or more episodes) was 11.9%. Significant differences were observed with respect to nursery attendance (OR: 1.71 [1.08-2.72]), the presence of eczema at this age (OR: 2.55 [1.48-4.42]), a history of maternal asthma (OR: 2.19 [1.08-4.44]) and exclusive breastfeeding for <3 months (OR: 1.53 [0.98-2.38]). CONCLUSIONS: In the province of Salamanca, one third of the infants studied suffered wheezing in the first year of life. Infants exclusively breastfed for less than three months; attending a nursery; having suffered eczema; or with an asthmatic mother showed significantly more wheezing than the rest. Wheezing proved recurrent in 11.9% of the cases.
Assuntos
Sons Respiratórios , Asma/epidemiologia , Estudos Transversais , Eczema/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Prevalência , Fatores de Risco , Espanha/epidemiologia , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Associations found in time-series studies on hospital emergency room (ER) visits due to asthma and chronic obstructive pulmonary disease (COPD) with single air pollutants show some lack of consistency. The respiratory effects of aeroallergens in the air pollution mix are not well established. Non-linear relationships of different airborne pollen types with certain respiratory diseases have also been described. We aim to study the short-term effects of major air pollutants and aeroallergen pollen on asthma and COPD hospital ER visits in the industrial and Mediterranean Spanish city of Cartagena during 1995-1998. METHODS: The association of asthma and COPD to ER visits with mean levels of sulphur and nitrogen dioxides (SO(2) and NO(2)), total suspended particles (TSP), ozone (O(3)), and the main allergenic airborne pollen types were analysed using Poisson regression with Generalised Additive Models, taking into account delayed effects and adjusting for long-term trends, seasonality, weather conditions, holidays and flu notifications. RESULTS: Multipollutant models showed a similar relative risk (RR) increase (in %), of around 5% in asthma and COPD ER visits per 10 µg/m(3) SO(2) increments. The risk of an ER visit for the same NO(2) increment was 2.6% for asthma and 3.3% for COPD. Visits to the ER due to asthma showed a positive increase with both Urticaceae and Poaceae levels, but did not substantially modify the previous percentages. CONCLUSIONS: Air levels of SO(2) and NO(2) were associated with a substantial increased risk in ER visits due to asthma and COPD. The inclusion of Poaceae and Urticaceae pollen did not alter that association.
Assuntos
Poluentes Atmosféricos/efeitos adversos , Asma/epidemiologia , Serviços Médicos de Emergência/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Pólen/efeitos adversos , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Alérgenos/efeitos adversos , Alérgenos/imunologia , Humanos , Região do Mediterrâneo , Dióxido de Nitrogênio/efeitos adversos , Ozônio/efeitos adversos , Poaceae/efeitos adversos , Pólen/classificação , Estações do Ano , Espanha , Dióxido de Enxofre/efeitos adversos , População Urbana , Urticaceae/efeitos adversosRESUMO
BACKGROUND: The International Study of Asthma and Allergies in Childhood (ISAAC) identified trends in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema over a seven-year period. We hypothesised that environmental influences on the three diseases are different and therefore investigated the correlation over time between trends in the prevalence of these diseases and their combinations at centre and individual level. METHODS: Centre level analyses were correlations between time trends in the prevalence of symptoms. At an individual level, odds ratios were calculated for associations between symptoms between Phases One and Three. We also investigated potential effect modification in the younger versus older age group; male versus female; and by average Gross National Income per capita (GNI). RESULTS: Both phases were completed in 66 centres in 37 countries for the 6-7 year age group and in 106 centres in 56 countries for the 13-14 year age group. We found that the correlations in time trends were stronger for the older age group than the younger one. Between symptoms of diseases, correlations of time trends were the strongest for rhinoconjunctivitis with eczema and weakest for eczema with asthma. The relationship between the three diseases was generally consistent over the seven-year period, and there was little association found with average GNI. CONCLUSIONS: Despite some increase in the proportion of children with symptoms of asthma, rhinoconjunctivitis and eczema, the pattern between the three diseases has not changed much, suggesting that similar factors may be affecting them at a global level.