Impact of Initiating Biologics In Patients on Long-Term OCS Or Frequent Rescue Steroids (GLITTER)

Study type

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

  Effectiveness study (incl. comparative)

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:
  8395

Study design details

• Main study objective:
  The aim is to describe the pattern of use and examine the impact on health outcomes of initiating biologic therapy in a real-world severe asthma population.
• Outcomes:
  To describe the demographic, clinical features, medication uses and comorbidities of adult severe asthma population with high SCS use, comparing between those who initiated a biologic therapy and those that did not initiate biologic therapy. To examine the comparative effectiveness of initiating a biologic therapy in adult severe asthma population with high SCS, comparing to those who did not initiate biologic therapy. Outcomes include exacerbations, asthma control, reduction/discontinuation of SCS and SCS-related comorbidity incidence.
• Data analysis plan:
  The clinical effectiveness of those that were exposed to high-dose systemic corticoSteroids (SCS) that initiated a biologic will be compared to those that remained on high-SCS. Primary outcome, exacerbation: As the dispersion of the data is expected to be high and as this outcome is conditional on the duration of follow-up, we plan to apply a negative binomial regression to estimate the reduced rate of exacerbation. Group comparisons will be made if interactions between groups is found. Secondary outcome, SCS dose: Generalized linear model (GLM) with generalized estimation equation (GEE) will be applied to estimate the reduced SCS dose across groups while accounting for intra-patient correlation. Secondary outcome, health resource utilization: The difference in the number of incident hospital or emergency room visits in the outcome period across groups will be examined similar to the primary outcome discussed above.