Geographical and social class effects on asthma mortality in England and Wales

Impact of Socioeconomic Status on Adult Patients with Asthma: A Population-Based Cohort Study from UK Primary Care

Introduction

Asthma morbidity and health-care utilization are known to exhibit a steep socioeconomic gradient. Further investigation into the modulators of this effect is required to identify potentially modifiable factors.

Methods

We identified a cohort of patients with asthma from the Optimum Patient Care Research Database (OPCRD). We compared demographics, clinical variables, and health-care utilization by quintile of the UK 2011 Indices of Multiple Deprivation based on the location of the patients’ general practice. Multivariable analyses were conducted using generalized linear models adjusting for year, age, and sex. We conducted subgroup analyses and interaction tests to investigate the impact of deprivation by age, sex, ethnicity, and treatment step.

Results

Our analysis included 127,040 patients with asthma. Patients from the most deprived socio-economic status (SES) quintile were more likely to report uncontrolled disease (OR: 1.54, 95% CI: 1.16, 2.05) and to have an exacerbation during follow-up (OR: 1.27, 95% CI: 1.13, 1.42) than the least deprived quintile. They had higher blood eosinophils (ratio: 1.03; 95% CI: 1.00, 1.06) and decreased peak flow (ratio: 0.95, 95% CI: 0.94, 0.97) when compared to those in the least deprived quintile. The effect of deprivation on asthma control was greater among those aged over 75 years (OR = 1.81, 95% CI: 1.20, 2.73) compared to those aged less than 35 years (OR: 1.22, 95% CI: 0.85, 1.74; p_interaction=0.019). Similarly, socioeconomic disparities in exacerbations were larger among those from ethnic minority groups (OR: 1.94, 95% CI: 1.40, 2.68) than white patients (OR: 1.24, 95% CI: 1.10, 1.39; p_interaction=0.012).

Conclusion

We found worse disease control and increased exacerbation rates among patients with asthma from more deprived areas. There was evidence that the magnitude of socioeconomic disparities was elevated among older patients and those from ethnic minority groups. The drivers of these differences require further exploration.

Persistent variations in national asthma mortality, hospital admissions and prevalence by socioeconomic status and region in England

BACKGROUND

The UK-wide National Review of Asthma Deaths sought to identify avoidable factors from the high numbers of deaths, but did not examine variation by socioeconomic status (SES) or region.

METHODS

We used asthma deaths in England over the period 2002-2015 obtained from national deaths registers, summarised by quintiles of Index of Multiple Deprivation (IMD) and Government Office Region. Emergency asthma admissions were obtained from Hospital Episode Statistics for England 2001-2011. The prevalence of asthma was derived from the Health Survey for England 2010. Associations of mortality, admissions and prevalence with IMD quintile and region were estimated cross-sectionally using incidence rate ratios (IRRs) adjusted for age and sex and, where possible, smoking.

RESULTS

Asthma mortality decreased among more deprived groups at younger ages. Among 5-44 year olds, those in the most deprived quintile, mortality was 19% lower than those in the least deprived quintile (IRR 0.81 (95% CI 0.69 to 0.96). In older adults, this pattern was reversed (45-74 years: IRR 1.37 (1.24-1.52), ≥75 years: IRR 1.30 (1.22-1.39)). In 5-44 year olds the inverse trend with asthma mortality contrasted with large positive associations for admissions (IRR 3.34 (3.30-3.38)) and prevalence of severe symptoms (IRR 2.38 (1.70-3.33)). Prevalence trends remained after adjustment for smoking. IRRs for asthma mortality, admissions and prevalence showed significant heterogeneity between English regions.

CONCLUSIONS

Despite asthma mortality, emergency admissions and prevalence decreasing over recent decades, England still experiences significant SES and regional variations. The previously undocumented inverse relation between deprivation and mortality in the young requires further investigation.

More surprises in the global greenhouse: Human health impacts from recent toxic marine aerosol formations, due to centennial alterations of world-wide coastal food webs

Reductions of zooplankton biomasses and grazing pressures were observed during overfishing-induced trophic cascades and concurrent oil spills at global scales. Recent phytoplankton increments followed, once Fe-, P-, and N-nutrient limitations of commensal diazotrophs and dinoflagellates were also eliminated by respective human desertification, deforestation, and eutrophication during climate changes. Si-limitation of diatoms instead ensued during these last anthropogenic perturbations of agricultural effluents and sewage loadings. Consequently, ~15% of total world-wide annual asthma trigger responses, i.e. amounting to ~45 million adjacent humans during 2004, resulted from brevetoxin and palytoxin poisons in aerosol forms of western boundary current origins. They were denoted by greater global harmful algal bloom [HAB] abundances and breathing attacks among sea-side children during prior decadal surveys of asthma prevalence, compiled here in ten paired shelf ecosystems of western and eutrophied boundary currents. Since 1965, such inferred onshore fluxes of aerosolized DOC poisons of HABs may have served as additional wind-borne organic carriers of toxic marine MeHg, phthalate, and DDT/DDE vectors, traced by radio-iodine isotopes to potentially elicit carcinomas. During these exchanges, as much as 40% of mercury poisonings may instead have been effected by inhalation of collateral HAB-carried marine neurotoxic aerosols of MeHg, not just from eating marine fish. Health impacts in some areas were additional asthma and pneumonia episodes, as well as endocrine disruptions among the same adjacent humans, with known large local rates of thyroid cancers, physician-diagnosed pulmonary problems, and ubiquitous high indices of mercury in hair, pesticides in breast milk, and phthalates in urine.

The relationship between socio-economic and geographic factors and asthma among Canada's Aboriginal populations

OBJECTIVES

To examine the prevalence, exacerbations and management of asthma among Canada's Aboriginal populations, and its relationship to socio-economic and geographic factors.

STUDY DESIGN

Secondary analysis of a national cross-sectional questionnaire survey.

METHODS

Data were collected in 2000 and 2001 through a survey of Aboriginal children and adults residing on- and off-reserve as part of the 2001 Aboriginal People's Survey (APS). The asthma related outcome variables - physician-diagnosed asthma, attack in past year and regular use of inhalants - were examined in relation to socio-economic and geographic factors such as income, education, housing and location of residence. Statistical analyses were based on weighted univariate and multivariate logistic regressions.

RESULTS

The results show variations in asthma diagnosis, attacks and inhalant use across geographic location, socio-economic and demographic characteristics. Geographic location was found to be significantly associated with asthma for both adults and children, with those living in the northern territories, on-reserve or rural locations being the least likely to be diagnosed. Geographic location and Aboriginal identity were also found to be significantly associated with asthma medication use.

CONCLUSIONS

While these findings may suggest a "healthier" population in more remote locations, they alternatively point to a general pattern of under-diagnosis, potentially due to poor health care access, as is typical in more remote locations.

Case-control study of severe life threatening asthma (SLTA) in a developing community

BACKGROUND

Distinct risk factors for asthma death have not been identified in developing communities. This study was conducted to distinguish risk factors for severe life threatening asthma (SLTA), a proxy for asthma death, in a developing country.

METHODS

A case-control study was performed at a University Hospital serving developing communities in the Western Cape Province, South Africa, over the period October 1997 to April 2000. Thirty consecutive patients with SLTA admitted to the intensive care unit (ICU) were compared with 60 chronic asthmatic patients, without a history of SLTA, who had attended the hospital outpatient respiratory clinic over the same period.

RESULTS

The risk of SLTA in comparison with controls increased with female sex (odds ratio (OR) 3.3, 95% CI 1.2 to 9.6, p = 0.02), rural residence (OR 8.1, 95% CI 2.6 to 25.3, p = 0.0005), and absence of a formal income (OR 5.7, 95% CI 2 to 16.6, p = 0.002). Cases were more likely to have had more than one hospital admission in the previous year (OR 8, 95% CI 2.5 to 25.2, p = 0.0009) and more than one emergency room visit in the previous year (OR 4.4, 95% CI 1.19 to 16.4, p = 0.04). Patients with SLTA were less likely to use inhaled corticosteroids (OR 5.6, 95% CI 1.9 to 16.5, p = 0.003) and more likely to use inhaled fenoterol (OR 6, 95% CI 2.2 to 16.2, p = 0.0004). Patients with SLTA also had lower mean (SE) forced expiratory volume in 1 second (FEV(1)) measurements (66.9 (9.5)% predicted v 82.5 (4.0)% predicted; p = 0.03) and lower FEV1/FVC ratios (60.7 (4.1)% predicted v 69.6 (1.9)% predicted; p = 0.05) documented before the episode of SLTA.

CONCLUSIONS

Risk factors for SLTA that are mainly analogous to those distinguished in other environments have been identified in a geographical area characterised by a third world socioeconomic context. Rural residence and poverty may increase the risk of SLTA.

Reconcilable differences: a cross-sectional study of the relationship between socioeconomic status and the magnitude of short-acting beta-agonist use in asthma

STUDY OBJECTIVE

To assess the association between socioeconomic status (SES) and short-acting (SA) beta-agonist use, controlling for asthma severity.

DESIGN

Cross-sectional study.

SETTING

Vancouver, BC, Canada.

PARTICIPANTS

Two hundred two asthmatics between 19 years and 50 years of age and residing in the greater Vancouver regional district.

MEASUREMENTS

The quantity of SA beta-agonist used in the previous year was collected by self-report; pulmonary function and beta-receptor genotype were measured on each participant. SES was measured at both the individual and population levels. Five methods of adjustment for asthma severity were used, as follows: the Canadian Asthma Consensus Guidelines, three previously developed asthma-severity scores, and forward stepwise multiple regression modeling. Polychotomous logistic regression was used to assess all relationships.

RESULTS

Independent of the method used to measure SES or adjust for asthma severity, lower SES was consistently and significantly associated with the use of greater amounts of SA beta-agonist. Adjusting for severity using the multivariate model explained the most variance of SA beta-agonist use (R(2) adjusted, 0.35 to 0.37). In this model, social assistance recipients were more likely to use greater amounts of SA beta-agonist (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.7 to 6.5). An inverse relationship between SA beta-agonist use and both annual household income (> $50,000; OR, 0.28; 95% CI, 0.13 to 0.60; and $20,000 to $50,000; OR, 0.44; 95% CI, 0.21 to 0.96; relative to <$20,000) and education (completing a bachelor's degree vs no formal education; OR, 0.25; 95% CI, 0.14 to 0.71). Participants living in a neighborhood with higher median household income (OR, 0.91; 95% CI, 0.84 to 0.98 per $1,000 increase) or a higher prevalence of having attained a bachelor's degree (OR, 0.96; 95% CI, 0.84 to 0.98 per 1% increase) were also less likely use greater amounts of SA beta-agonist. Results were consistent for neighborhood unemployment rate.

CONCLUSIONS

The social gradient in asthma-related outcomes may be at least partially attributable to poorer asthma control in lower-SES asthmatics.

Dyspnea and 8-year mortality among elderly men and women: the PAQUID cohort study

PAQUID is an epidemiological cohort which aims to study cerebral and functional factors of ageing. We have examined the relationship between dyspnea level at entrance into this cohort and mortality occurring during the subsequent 8 years. Dyspnea was evaluated by a questionnaire derived from a Fletcher's five-degree scale. Mortality was recorded during follow-up according to its date and cause. Of 2762 subjects (98.9%) initially giving their dyspnea level, 935 (33.5%) had died 8 years later including 444 (40%) men and 491 (29.4%) women. Mortality was closely related to dyspnea level (p < 0.0001) both in men and women, especially for grade 3 and over, even after adjusting on age, sex, smoking history and former occupation. These results show that dyspnea grade 3 or higher is an important predictive symptom of mortality, thus suggesting that this is a threshold defining the dyspneic subject.

Socioeconomic differences in children's health: how and why do these relationships change with age?

The effects of socioeconomic status (SES) on health are well documented in adulthood, but far less is known about its effects in childhood. The authors reviewed the literature and found support for a childhood SES effect, whereby each decrease in SES was associated with an increased health risk. The authors explored how this relationship changed as children underwent normal developmental changes and proposed 3 models to describe the temporal patterns. The authors found that a model's capacity to explain SES-health relationships varied across health outcomes. Childhood injury showed stronger relationships with SES at younger ages, whereas smoking showed stronger relationships with SES in adolescence. Finally, the authors proposed a developmental approach to exploring mechanisms that link SES and child health.

Social class, smoking and the severity of respiratory symptoms in the general population

STUDY OBJECTIVE

The prevalence of respiratory symptoms has been found in some studies to vary with social class. One explanation of this link may be the effect of exposure to cigarette smoke. To investigate this, the relation between social class, smoking and respiratory symptoms was explored in a population based survey.

DESIGN

A cross sectional survey using a validated questionnaire.

SETTING

Two general practices in Staffordshire, United Kingdom.

PATIENTS

A random sample of 4237 patients aged 16 and over from two general practices in Staffordshire were mailed a questionnaire enquiring about respiratory symptoms and their severity.

MAIN RESULTS

The severity of respiratory symptoms increased with increasing exposure to cigarette smoke and was greater among manual social classes. Current smokers (odds ratio (OR) = 2.9, 95% confidence limits (CI) 2.3, 3.6), past smokers (OR = 1.5, 95% CI 1.2, 1.8) and passive smokers (OR = 1.4, 95% CI 1.0, 1.8) were more likely to report the more severe respiratory symptoms compared with non-smokers. Responders from social class V (OR = 2.4, 95% CI 1.3, 4. 4) were more likely to report the more severe respiratory symptoms compared with social class I, as were responders from social classes IIIM (OR = 1.3, 95% CI 0.9, 1.9) and IV (OR = 1.4, 95% CI 0.9, 2.1). These effects were independent of each other.

CONCLUSIONS

This study has shown that social class is linked to the severity of respiratory symptoms, independently of smoking. Although the need to reduce and quit smoking in manual class households remains a crucial preventive issue, other mechanisms by which social class differences may influence symptom occurrence and severity need to be explored.

Geographical and socioeconomic variation in the prevalence of asthma symptoms in English and Scottish children

BACKGROUND

There has been controversy over the relation between poverty and asthma in the community. The aim of this analysis was to disentangle geographical and socioeconomic variation in asthma symptoms.

METHODS

The analysis is based on parental reports of symptoms from data collected in 1990 and 1991. Children aged 5-11 years from three populations (English representative sample, Scottish representative sample, and an English inner city sample) were included. Of 17 677 eligible children, between 14 490 (82.0%) and 15 562 (88.0%) children were available for analysis according to symptom group.

RESULTS

Wheezy symptoms were less prevalent in the Scottish sample than in the English samples and asthma attacks were most prevalent in the English representative sample. Asthma attacks were less prevalent in inner city areas than in the English representative sample (OR 0.79, 95% CI 0.66 to 0.95), but persistent wheeze and other respiratory symptoms were more prevalent (OR 1.95, 95% CI 1.65 to 2.32 and OR 1.67, 95% CI 1.52 to 1.84, respectively). The prevalence of persistent wheeze was higher in children whose father's social class was low and in those living in areas with a high Townsend score (an index of poverty) than in other children (p<0.001). Of the 14 areas with the highest Townsend score, 13 had an OR above 1 and six had an OR significantly higher than the reference area.

CONCLUSIONS

Persistent wheeze is more prevalent in poor areas than in less deprived areas. This may indicate that poverty is associated with severe asthma or that a high percentage of persistent asthma symptoms in inner city areas are unrecognised and untreated.