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

Abstract

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.

Keywords: asthma epidemiology.

Figure 1

Socioeconomic status variations in asthma outcomes in England, standardised event ratios by Index of Multiple Deprivation (IMD; 1 is least deprived), sex and age-band, with 95% CI bars: (A) mortality 2002–2015, Office for National Statistics mortality; (B) emergency admissions 2001–2011, Hospital Episode Statistics; (C) prevalence of clinician-diagnosed and treated asthma 2010*, Health Survey for England 2010; (D) prevalence of recent severe asthma 2010*, Health Survey for England 2010. Footnotes. †95% CI too small to be visible. *Clinician-diagnosed-and-treated asthma; a combination of the questions: ‘Did a doctor or nurse ever tell you that you had asthma?’ AND ‘Over the last 12 months, have you used an inhaler, puffer or nebuliser prescribed by a doctor to treat your asthma, wheezing or whistling, or difficulty in breathing?’. Recent severe asthma; a combination of any of the following: in the last 12 months has had sleep disturbed one or more nights per week due to wheezing/whistling in chest, has found in the last 12 months chest wheezing ±whistling interfered with normal activities ‘quite a bit’ or ‘a lot’, has experienced symptoms of asthma ‘every day’ or ‘most days’, had difficulty sleeping one or more days due to usual asthma symptoms in the last week or had usual asthma symptoms during the day one or more days in the last week. Presented as simple prevalences (%) due to small numbers.

Figure 2

Regional variations in asthma outcomes in England, standardised event ratios by English Government Office Region and sex, with 95% CI bars, ranked by the Standard Events Ratios (SERs) for mortality in males and females combined: (A) mortality 2002–2015, ONS mortality; (B) emergency admissions 2008–12, Hospital Episode Statistics; (C) prevalence of clinician-diagnosed-and-treated asthma 2010, Health Survey for England 2010; (D) prevalence of recent severe asthma 2010*, Health Survey for England 2010. Footnotes. †95% CI too small to be visible. *Clinician-diagnosed-and-treated asthma; a combination of the questions: ‘Did a doctor or nurse ever tell you that you had asthma?’ AND ‘Over the last 12 months, have you used an inhaler, puffer or nebuliser prescribed by a doctor to treat your asthma, wheezing or whistling, or difficulty in breathing?’. Recent severe asthma; a combination of any of the following: in the last 12 months has had sleep disturbed one or more nights per week due to wheezing/whistling in chest, has found in the last 12 months chest wheezing ±whistling interfered with normal activities ‘quite a bit’ or ‘a lot’, has experienced symptoms of asthma ‘every day’ or ‘most days’, had difficulty sleeping one or more days due to usual asthma symptoms in the last week or had usual asthma symptoms during the day one or more days in the last week. Government Office Regions (GOR), SW South West, NE North East, E East of England, EM East Midlands, NW North West, Lon London, YH Yorkshire and Humberside, WM West Midlands.