Exploring differences in asthma disease severity and pathways: variation by ethnicity and socioeconomic status

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Disease epidemiology

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Medical condition to be studied:
  Asthma

Population studied

• Age groups:
  Adults (18 to < 46 years)

  Adults (46 to < 65 years)

  Adults (65 to < 75 years)

  Adults (75 to < 85 years)

  Adults (85 years and over)
• Estimated number of subjects:
  100000

Study design details

• Main study objective:
  • Explore differences in asthma severity, control and phenotype by ethnic and socioeconomic groups• Explore patterns of medication usage and healthcare utilisation in different ethnic and socioeconomic groups• Identify determinants of asthma severity in different ethnic and socioeconomic groups• Identify disparities in referrals for patients from different ethnic and socioeconomic groups
• Outcomes:
  Asthma severity will be ascertained using medication prescription data. Patients will be categorised according to the treatment steps described by GINA, Lung function measurementsBlood eosinophil countsHospital admissions A&E attendancesGP consultationsAsthma exacerbationsMaintenance medication adherence Time to treatment escalationTime to specialist referral
• Data analysis plan:
  Descriptive statistics: Descriptive statistics will be calculated for the entire cohort and separately for each ethnic and socioeconomic groupSeverity prevalence: appropriate 95% confidence intervals calculated using the multinomial distribution. Multivariable analysis will be conducted using ordinal logistic regression.Care pathways: The number of hospital admissions, A&E attendances, GP consultations and asthma exacerbations will be analysed using Poisson regression. Lung function measurements, blood eosinophil counts and the prescription possession ratio will be analysed using linear regression. Patients who have their treatment escalated following a loss of control will be investigated using logistic regression. The time between eligibility for specialist referral and attendance will be analysed using Cox regression.Unadjusted analyses and adjusted analysis (accounting for difference in demographics, lifestyle factors etc.) will be presented