The role of adherence to inhaled corticosteroids in the relationship between blood eosinophilia and asthma control

Study type

• Study topic:
  Disease /health condition

  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Disease epidemiology
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Medical condition to be studied:
  Asthma

Population studied

• Short description of the study population:
  Asthma patients with raised blood eosinophil counts at steps 3 and 4 of the GINA guidelines.
• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Special population of interest:
  Other
• Special population of interest, other:
  Asthma patients
• Estimated number of subjects:
  7195

Study design details

• Main study objective:
  To investigate whether poor adherence to ICS therapy explains occurrence of exacerbations or poor asthma control in patients with raised blood eosinophil counts at steps 3 and 4 of the GINA guidelines.
• Outcomes:
  Demographic and clinical characteristics of the patients with raised and normal eosinophil levels at steps 3 or 4 of the GINA guidelines. Patterns of adherence to the ICS treatment in the asthma patients with raised and normal blood eosinophil levels at steps 3 and 4 of the GINA guidelines
• Data analysis plan:
  Descriptive statistics of the demographic and clinical characteristics of the patients with raised and normal eosinophil levels at steps 3 or 4 of the GINA guidelines will be produced. The number (%) of patients with exacerbations (routine, patient-reported and combined variables) and the proportion of patients with controlled asthma (routine and patient-reported variables) will be calculated. Sensitivity analyses for patients with good treatment adherence (>80%), as well as for lower adherence levels (≤80%) using eosinophils recordings within one year from questionnaire collection and lower cut-off for eosinophil levels (>0.3 x 109/L and ≤0.3 x 109/L) will be performed.Statistically significant results will be defined as p < 0.05 and trends as 0.05 ≤ p < 0.10. Differences between groups will be evaluated through Chi-square or Mann-Whitney U tests, as appropriate. Intra-group differences will be evaluated through Chi-square test (p<0.05).