Socioeconomic inequalities in asthma and respiratory symptoms in a high-income country: changes from 1996 to 2016.

Objective: Low socioeconomic status based both on educational level and income has been associated with asthma and respiratory symptoms, but changes over time in these associations have rarely been studied. The aim was to study the associations between educational or income inequality and asthma and respiratory symptoms among women and men over a 20-year period in northern Sweden. Methods: The study was performed within the Obstructive Lung disease in Northern Sweden (OLIN) research program. Mailed questionnaire surveys were administered to a random sample of adults (20-69 years of age) living in Sweden, in 1996, 2006 and 2016. Data on educational level and income were collected from the national integrated database for labor market research. Results: The educational inequality associated with asthma and asthmatic wheeze tended to decrease from 1996 to 2016, while it increased for productive cough, the latter among men not among women. The income inequality decreased for productive cough, especially for women, while no clear overall trends were found for asthmatic wheeze and asthma, apart from a decrease in income inequality regarding asthma among men. Conclusion: The patterns for socioeconomic inequality differed for asthma and wheeze compared to productive cough, and the results emphasize that education and income do not mirror the same aspects of socioeconomic inequality in a high-income country. Our findings are important for decision makers, not the least on a political level, as reduced inequality, e.g. through education, could lead to reduced morbidity.

Occupation, socioeconomic status and chronic obstructive respiratory diseases - The EpiLung study in Finland, Estonia and Sweden.

OBJECTIVE: To study occupational groups and occupational exposure in association with chronic obstructive respiratory diseases. METHODS: In early 2000s, structured interviews on chronic respiratory diseases and measurements of lung function as well as fractional expiratory nitric oxide (FENO) were performed in adult random population samples of Finland, Sweden and Estonia. Occupations were categorized according to three classification systems. Occupational exposure to vapours, gases, dusts and fumes (VGDF) was assessed by a Job-Exposure Matrix (JEM). The data from the countries were combined. RESULTS: COPD, smoking and occupational exposure were most common in Estonia, while asthma and occupations requiring higher educational levels in Sweden and Finland. In an adjusted regression model, non-manual workers had a three-fold risk for physician-diagnosed asthma (OR 3.18, 95%CI 1.07-9.47) compared to professionals and executives, and the risk was two-fold for healthcare & social workers (OR 2.28, 95%CI 1.14-4.59) compared to administration and sales. An increased risk for physician-diagnosed COPD was seen in manual workers, regardless of classification system, but in contrast to asthma, the risk was mostly explained by smoking and less by occupational exposure to VGDF. For FENO, no associations with occupation were observed. CONCLUSIONS: In this multicenter study from Finland, Sweden and Estonia, COPD was consistently associated with manual occupations with high smoking prevalence, highlighting the need to control for tobacco smoking in studies on occupational associations. In contrast, asthma tended to associate with non-manual occupations requiring higher educational levels. The occupational associations with asthma were not driven by eosinophilic inflammation presented by increased FENO.

Childhood onset asthma is associated with lower educational level in young adults - A prospective cohort study.

BACKGROUND: Asthma is associated with low socioeconomic status among both children and adults, and adolescents with asthma report more school absenteeism than those without. However, it is unclear whether asthma in childhood and adolescence affects socioeconomic status in adulthood. METHODS: Within the Obstructive Lung disease In Northern Sweden Studies, all children in grade 1 and 2 in three municipalities were invited to a questionnaire survey, 97% participated (n = 3430). They were followed annually until age 19, and thereafter at age 28 years. In this study, participants at ages 8 y, 12 y, 19 y and 28 y (n = 2017) were included. Asthma was categorized into childhood onset (up to age 12 y) and adolescent onset (from 12 to 19 y). Data for assessment of socioeconomic status was collected at 28 y and included educational level, occupation, and occupational exposure to gas, dust and/or fumes (GDF). RESULTS: Childhood onset asthma was associated with having compulsory school as the highest educational level at age 28 y, also after adjustment for sex, smoking and BMI at age 19 y and socioeconomic factors in childhood (OR 4.84 95%CI 2.01-11.65), and the pattern was the same among men and women. However, we found no significant associations between asthma in childhood or adolescence and socioeconomic groups, occupational groups or occupational exposure to GDF at age 28 y. CONCLUSIONS: Even though asthma in high-income countries, such as Sweden, is well recognised and treated, this study highlight that childhood onset asthma may have a negative long-term effect with regard to educational level in young adulthood.

Low socioeconomic status relates to asthma and wheeze, especially in women.

Low socioeconomic status (SES) has been associated with asthma and wheezing. Occupational group, educational level and income are commonly used indicators for SES, but no single indicator can illustrate the entire complexity of SES. The aim was to investigate how different indicators of SES associate with current asthma, allergic and nonallergic, and asthmatic wheeze. In 2016, a random sample of the population aged 20-79 years in Northern Sweden were invited to a postal questionnaire survey, with 58% participating (n=6854). The survey data were linked to the national Integrated Database for Labour Market Research by Statistics Sweden for the previous calendar year, 2015. Included SES indicators were occupation, educational level and income. Manual workers had increased risk for asthmatic wheeze, and manual workers in service for current asthma, especially allergic asthma. Primary school education associated with nonallergic asthma, whereas it tended to be inversely associated with allergic asthma. Low income was associated with asthmatic wheeze. Overall, the findings were more prominent among women, and interaction analyses between sex and income revealed that women, but not men, with low income had an increased risk both for asthmatic wheeze and current asthma, especially allergic asthma. To summarise, the different indicators of socioeconomic status illustrated various aspects of associations between low SES and asthma and wheeze, and the most prominent associations were found among women.

Job titles classified into socioeconomic and occupational groups identify subjects with increased risk for respiratory symptoms independent of occupational exposure to vapour, gas, dust, or fumes.

Objectives: To evaluate the ability of three different job title classification systems to identify subjects at risk for respiratory symptoms and asthma by also taking the effect of exposure to vapours, gas, dust, and fumes (VGDF) into account. Background: Respiratory symptoms and asthma may be caused by occupational factors. There are different ways to classify occupational exposure. In this study, self-reported occupational exposure to vapours, gas, dust and fumes was used as well as job titles classifed into occupational and socioeconomic Groups according to three different systems. Design: This was a large population-based study of adults aged 30-69 years in Northern Sweden (n = 9,992, 50% women). Information on job titles, VGDF-exposure, smoking habits, asthma and respiratory symptoms was collected by a postal survey. Job titles were used for classification into socioeconomic and occupational groups based on three classification systems; Socioeconomic classification (SEI), the Nordic Occupations Classification 1983 (NYK), and the Swedish Standard Classification of Occupations 2012 (SSYK). Associations were analysed by multivariable logistic regression. Results: Occupational exposure to VGDF was a risk factor for all respiratory symptoms and asthma (odds ratios (ORs) 1.3-2.4). Productive cough was associated with the socioeconomic groups of manual workers (ORs 1.5-2.1) and non-manual employees (ORs 1.6-1.9). These groups include occupations such as construction and transportation workers, service workers, nurses, teachers and administration clerks which by the SSYK classification were associated with productive cough (ORs 2.4-3.7). Recurrent wheeze was significantly associated with the SEI group manual workers (ORs 1.5-1.7). After adjustment for also VGDF, productive cough remained significantly associated with the SEI groups manual workers in service and non-manual employees, and the SSYK-occupational groups administration, service, and elementary occupations. Conclusions: In this cross-sectional study, two of the three different classification systems, SSYK and SEI gave similar results and identified groups with increased risk for respiratory symptoms while NYK did not give conclusive results. Furthermore, several associations were independent of exposure to VGDF indicating that also other job-related factors than VGDF are of importance.

Occupational exposure to chemicals drives the increased risk of asthma and rhinitis observed for exposure to vapours, gas, dust and fumes: a cross-sectional population-based study.

OBJECTIVES: Occupational exposure to the composite measure vapours, gases, dusts and fumes (VGDF), contribute to the burden of asthma and rhinitis. The objective was to evaluate occupational exposure to VGDF, which is further divided into the components chemicals, organic and inorganic dust in relation to asthma and rhinitis. METHODS: Previously examined participants from three population-based cohorts in the Obstructive Lung disease In Northern Sweden (OLIN) studies were re-examined during 2002-2004. In total, 4036 participated in a structured interview and answered a questionnaire on occupational exposures. RESULTS: Occupational exposure to VGDF increased the risk of asthma, and concomitant asthma and rhinitis. Exposure to chemicals, but not dust, showed a similar pattern. Exposure to chemicals increased the risks (OR, 95% CI) of rhinitis without asthma (1.29, 1.10 to 1.52), asthma without rhinitis (1.42, 1.15 to 1.77) and concomitant asthma and rhinitis (1.60, 1.31 to 1.96) when adjusted for confounders such as age, smoking habits, body mass index and sex. The association between exposure to chemicals and asthma and rhinitis remained independent of exposure to dust and was also so when excluding exposure to isocyanates and welding fumes. The results were similar for women and men, as well as for never-smokers and participants without a history of allergy. CONCLUSIONS: In this cross-sectional population-based study, occupational exposure to chemicals contributed substantially to the increased risk of asthma and rhinitis observed for occupational exposure to VGDF.