[Changes in the prevalence of asthma in the Spanish cohort of the European Community Respiratory Health Survey (ECRHS-II)]. / Cambios en la prevalencia de asma en la población española del Estudio de Salud Respiratoria de la Comunidad Europea (ECRHS-II).

OBJECTIVE: The rise in the prevalence of asthma in the second half of the 20th century has not been evenly distributed according to recent surveys. We assessed changes in the prevalence of asthma after a period of 9 to 10 years in a cohort of young adults in the Spanish arm of the European Community Respiratory Health Survey (ECRHS). MATERIAL AND METHODS: The ECRHS-II is a multicenter cohort study taking place in 27 centers around Europe, with Spanish centers located in Albacete, Barcelona, Galdakao, Huelva, and Oviedo. The ECRHS questionnaire was administered to individuals who had participated in the first phase of the survey; spirometry and methacholine challenge tests were also performed according to the published protocol. RESULTS: Among new smokers, the prevalence of wheezing in the last 12 months increased from 10% to 33%, while the frequency of phlegm production rose from 8% to 22% (P< .05). In ex-smokers, the prevalences of wheezing and phlegm production decreased from 21% to 12% and from 15% to 8%, respectively (P< .05). Symptom prevalences remained similar for never smokers, although the frequency of diagnosed asthma rose from 4% to 7% (P< .05). After adjusting for smoking, age, sex, and center, we found no significant differences in the frequency of symptoms or asthma, even when the phrase bronchial hyperreactivity was included in the definition. However, the rate of reported asthma rose annually by 0.34% (95% confidence interval [CI], 0.20%-0.48%), while diagnosed asthma rose by 0.26% (95% CI, 0.13%-0.39%) and treated asthma by 0.16% (95% CI, 0.07%-0.25%). CONCLUSIONS: Increased prevalence rates of asthma diagnosis and treatment have been detected, but the rates of reported symptoms have remained similar, consistent with the assumption that more persons are being classified as asthmatics.

Cambios en la prevalencia de asma en la población española del Estudio de Salud Respiratoria de la Comunidad Europea (ECRHS-II) / Changes in the prevalence of asthma in the spanish cohort of the European Community Respiratory Health Survey (ECRHS-II)

Objetivo: El aumento de la frecuencia de asma ocurrido en la segunda mitad del siglo xx no es homogéneo entre los estudios más recientes. Hemos evaluado los cambios en la prevalencia de asma después de un seguimiento de 9-10 años en la población de adultos jóvenes del grupo español del Estudio de Salud Respiratoria de la Comunidad Europea (ECRHS). Material y métodos: El ECRHS-II es un estudio multicéntrico de seguimiento en 27 centros de Europa. Los centros españoles participantes se hallan en las ciudades de Albacete, Barcelona, Galdakao, Huelva y Oviedo. Se ha estudiado a los participantes del ECRHS-I mediante la utilización del cuestionario ECRHS y la realización de espirometría y test de metacolina según el protocolo ya publicado en trabajos anteriores. Resultados: La prevalencia de sibilancias en los últimos 12 meses en los nuevos fumadores aumenta del 10 al 33%, y la de expectoración, del 8 al 22%, mientras que entre quienes han abandonado el tabaco descienden del 21 al 12% y del 15 al 8%, respectivamente (p < 0,05). Entre los que nunca han fumado no se observan cambios en la prevalencia de síntomas, pero sí un aumento en la de asma diagnosticada (del 4 al 7%) (p < 0,05). Ajustando por hábito tabáquico, edad, sexo y centro no se observan cambios en los síntomas ni al introducir la hiperreactividad bronquial en la definición de asma, pero sí en el asma comunicada (un aumento del 0,34%; intervalo de confianza [IC] del 95%, 0,20-0,48%) por año, el asma diagnosticada (0,26%; IC del 95%, 0,13-0,39%) y el asma tratada (0,16%; IC del 95%, 0,07-0,25%). Conclusiones: Se aprecia un aumento de la prevalencia del diagnóstico de asma y del tratamiento del asma, que no se acompaña de un aumento de síntomas, lo que puede ser congruente con la idea de que hay una mayor clasificación de personas como asmáticas

Objective: The rise in the prevalence of asthma in the second half of the 20th century has not been evenly distributed according to recent surveys. We assessed changes in the prevalence of asthma after a period of 9 to 10 years in a cohort of young adults in the Spanish arm of the European Community Respiratory Health Survey (ECRHS). Material and methods: The ECRHS-II is a multicenter cohort study taking place in 27 centers around Europe, with Spanish centers located in Albacete, Barcelona, Galdakao, Huelva, and Oviedo. The ECRHS questionnaire was administered to individuals who had participated in the first phase of the survey; spirometry and methacholine challenge tests were also performed according to the published protocol. Results: Among new smokers, the prevalence of wheezing in the last 12 months increased from 10% to 33%, while the frequency of phlegm production rose from 8% to 22% (P<.05). In ex-smokers, the prevalences of wheezing and phlegm production decreased from 21% to 12% and from 15% to 8%, respectively (P<.05). Symptom prevalences remained similar for never smokers, although the frequency of diagnosed asthma rose from 4% to 7% (P<.05). After adjusting for smoking, age, sex, and center, we found no significant differences in the frequency of symptoms or asthma, even when the phrase bronchial hyperreactivity was included in the definition. However, the rate of reported asthma rose annually by 0.34% (95% confidence interval [CI], 0.20%-0.48%), while diagnosed asthma rose by 0.26% (95% CI, 0.13%-0.39%) and treated asthma by 0.16% (95% CI, 0.07%-0.25%). Conclusions: Increased prevalence rates of asthma diagnosis and treatment have been detected, but the rates of reported symptoms have remained similar, consistent with the assumption that more persons are being classified as asthmatics

Exposure to substances in the workplace and new-onset asthma: an international prospective population-based study (ECRHS-II).

BACKGROUND: The role of exposure to substances in the workplace in new-onset asthma is not well characterised in population-based studies. We therefore aimed to estimate the relative and attributable risks of new-onset asthma in relation to occupations, work-related exposures, and inhalation accidents. METHODS: We studied prospectively 6837 participants from 13 countries who previously took part in the European Community Respiratory Health Survey (1990-95) and did not report respiratory symptoms or a history of asthma at the time of the first study. Asthma was assessed by methacholine challenge test and by questionnaire data on asthma symptoms. Exposures were defined by high-risk occupations, an asthma-specific job exposure matrix with additional expert judgment, and through self-report of acute inhalation events. Relative risks for new onset asthma were calculated with log-binomial models adjusted for age, sex, smoking, and study centre. FINDINGS: A significant excess asthma risk was seen after exposure to substances known to cause occupational asthma (Relative risk=1.6, 95% CI 1.1-2.3, p=0.017). Risks were highest for asthma defined by bronchial hyper-reactivity in addition to symptoms (2.4, 1.3-4.6, p=0.008). Of common occupations, a significant excess risk of asthma was seen for nursing (2.2, 1.3-4.0, p=0.007). Asthma risk was also increased in participants who reported an acute symptomatic inhalation event such as fire, mixing cleaning products, or chemical spills (RR=3.3, 95% CI 1.0-11.1, p=0.051). The population-attributable risk for adult asthma due to occupational exposures ranged from 10% to 25%, equivalent to an incidence of new-onset occupational asthma of 250-300 cases per million people per year. INTERPRETATION: Occupational exposures account for a substantial proportion of adult asthma incidence. The increased risk of asthma after inhalation accidents suggests that workers who have such accidents should be monitored closely.

Lung function decline, chronic bronchitis, and occupational exposures in young adults.

RATIONALE: Occupational exposures to vapors, gas, dust, or fumes have been shown to be a risk factor of airway obstruction in cross-sectional studies in the general population. OBJECTIVES: Our aim was to study the relationships between specific occupations and occupational exposures during a 9-yr follow-up period and changes in lung function and symptoms of chronic bronchitis. METHODS: Subjects from the general population aged 20 to 45 yr were randomly selected in 1991-1993 within the European Community Respiratory Health Survey. Follow-up took place from 1998 to 2002 among 4,079 males and 4,461 females in 27 study centers. A total of 3,202 men and 3,279 women twice completed lung function measurements. Job history during follow-up was linked to a job exposure matrix and consequently translated into cumulative exposure estimates. MAIN RESULTS: Individuals exposed to dusts, gases, and fumes during the period of follow-up did not have a steeper decline of FEV1 than did individuals with consistently white-collar occupations without occupational exposures (relative change among men and women, + 1.4 and -3.1 ml/yr, respectively; p > 0.2), nor an increase of prevalence or incidence of airway obstruction defined as an FEV1/FVC ratio of less than 0.7. The incidence of chronic phlegm increased in men exposed to mineral dust (relative risk, 1.94 [1.29-2.91]) and gases and fumes (relative risk, 1.53 [0.99-2.36]), which was not modified by smoking. CONCLUSION: Occupational exposures to dusts, gases, and fumes occurring during the 1990s are associated with incidence of chronic bronchitis, although these did not impair lung function in a population of relatively young age.

Evaluation of specific occupational asthma risks in a community-based study with special reference to single and multiple exposures.

OBJECTIVES: To compare two job exposure matrices (JEMs) for the evaluation of asthma risks related to specific occupational exposures in a community-based study. METHODS: A questionnaire on self-reported asthma, respiratory symptoms and current occupation was sent to the participants of the European Community Respiratory Health Survey in five areas in Spain. Both an asthma-specific JEM, including expert judgment steps and a general JEM, were applied to occupational codes. Risks of current asthma symptoms and wheeze in the last year associated with the obtained exposure estimates were evaluated. Correlations between specific exposures were investigated using explanatory factor analysis. RESULTS: Occupational exposures to the high-molecular-weight (MW) agents flour dust, enzymes, mites and animal-derived proteins as obtained by the asthma-specific JEM were positively associated with asthma outcomes. The effect of additional expert judgment steps was limited. High exposures to biological dust assessed by the general JEM without expert judgment was also associated with asthma. Many of the exposed individuals worked in environments with multiple exposures. CONCLUSIONS: Asthma risks associated with occupational exposures to specific high-MW agents could be identified from a population-based study using an asthma-specific JEM. Application of JEMs can be a useful tool to estimate asthma risks attributable to specific occupational exposures in the general population. However, these specific exposure risks should be interpreted in connection with the whole of concomitant exposures constituting the work environment.