Biologic Usage Patterns, Clinical Outcomes and Healthcare Resource Utilization (CLEAR)

Study type

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

Non-interventional study

• Non-interventional study design:
  Cross-sectional

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:
  10000

Study design details

• Main study objective:
  The main objective is to describe the demographic and clinical characteristics (including biomarker characteristics), of five severe asthma patient groups based on patterns of biologic initiation (1. Initiated and switched, 2. Initiated and continued, 3. Initiated and stopped, 4. Not initiated but eligible for biologics, 5. Not initiated and not eligible for any biologics).
• Outcomes:
  Demographic & clinical characteristics of 5 severe asthma patient groups will be described based on biologic initiation patterns initiation (1.initiated & switched, 2.initiated and continued, 3.initiated and stopped, 4.not initiated but eligible for biologics, 5.not initiated & not eligible for any biologics). The primary outcome for objective 2 is post-therapy or post-ISAR enrolment exacerbation. The secondary outcome variables are LTOCS dose, asthma control and healthcare resource utilization.
• Data analysis plan:
  Descriptive statistics of the baseline (pre-therapy) Demographic & Clinical Variables for the five biologic utilization groups will be conducted for continuous & categorical variables accordingly. Continuous variables will be summarised using means, standard deviations, medians, ranges, and interquartile ranges. Categorical variables will be presented as counts and percentages. Standardized mean difference (SMD) will be used to quantify differences in both continuous and categorical variables between the biologic utilization groups at baseline. Once balance has been achieved across groups (initiators vs non-initiators, switchers, stoppers vs continuers), the following statistical model were applied to estimate parameters: Primary Outcome: exacerbation - a negative binomial regression (y=annual rate of exacerbation). Secondary Outcomes: •Asthma control - multinomial logistic regression model (ordered) •LTOCS dose – Generalized linear model (GLM) with generalized estimation equation