EXPLORING THE BIDIRECTIONAL RELATIONSHIP BETWEEN DATABASE MARKERS OF ASTHMA TREATMENT ADHERENCE AND ASTHMA-RELATED OUTCOMES (ICS ADHERENCE & ASTHMA CONTROL OUTCOMES)

Study type

• Study topic:
  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Effectiveness study (incl. comparative)

  Other
• If ‘other’, further details on the scope of the study:
  Adherence - asthma control interaction analysis
• 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.; Patients must meet the following inclusion criteria:; 1. Have 3-years of continuous medical records, including 1 year prior to the IPD and 2 years after the IPD.; 2. Received a physician-diagnosis of asthma (i.e. recorded diagnostic, Read Code) at least one year prior to the IPD.; 3. Aged ≥6 years at IPD (i.e. ≥5 years at time of recorded asthma diagnosis); 4. At the IPD, received their first prescription* for an ICS (any) delivered via metered dose inhaler (MDI) or dry powder inhaler (DPI); 5. On active asthma therapy (defined as ≥2 prescriptions for ICS and/or SABA at different points in time during each of the two outcome years).
• Age groups:
  Children (2 to < 12 years)

  Adolescents (12 to < 18 years)

  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)
• Special population of interest:
  Other
• Special population of interest, other:
  Asthma patients
• Estimated number of subjects:
  50000

Study design details

• Main study objective:
  To explore to what extent and in what contexts adherence may be considered an asthma outcome, or/and a predictor of asthma outcomes by conducting an observational study designed to investigate the bi-directional relationship between database markers of asthma treatment adherence and asthma control
• Outcomes:
  Database markers of adherence –prescription-based refill ratesComposite database markers of asthma controlModerate/Severe exacerbation (composite measures)SABA usage (proxy symptoms)Treatment stability (i.e. database marker of control and no use of additional therapy)
• Data analysis plan:
  Phase 1, longitudinal evaluation: Descriptive analysis of adherence, asthma outcomes and confounders over the study periodPhase 2: Cross-lagged panel design – SEM models of asthma adherence and outcomes: Associations between adherence and each outcome (in a cross-lagged panel analysis) using the number of time intervals selected in Phase 1.Phase 3: 3.Hierarchical longitudinal models – separate MLM models of adherence (MPR) and asthma outcomes: Predictors of between- and within-subject variance in adherence and outcomes will be explored via hierarchical longitudinal models. If possible, adherence and outcome variables will be coded both as simultaneous and as lagged measurements in separate models, to examine both types of relationships. Time-varying predictors will be recoded to distinguish between individual mean levels and within-person deviations from individual means