Relative effectiveness of mepolizumab and other biologics in routine clinical practice

Greater than equal to (>=)2 consecutive medical or pharmacy claims for the same biologic agent (mepolizumab, dupilumab, benralizumab, omalizumab, tezepelumab) on or after January 1, 2019 o The first observed claim will be defined as the index date and the second claim must occur within 6 months of the index date

• Greater than or equal to (>=12) months of Medicare FFS continuous clinical activity prior to the index date (Baseline period) o Continuous clinical activity will be defined as consecutive quarters with >=1 medical and >=1 pharmacy claim
• Greater than or equal to (>=)2 diagnosis of asthma in any position during the baseline period or on the index date
• Greater than or equal to (>=)18 years of age at the index date o While most Medicare FFS beneficiaries are aged >=65 years, some younger adults qualify for Medicare due to disability or specific medical conditions. Because asthma affects adults across a wide age range, including all participants aged >=18 years ensures comprehensive representation of the Medicare FFS population. This approach aligns with the Inflation Reduction Act (IRA) framework by capturing the full adult population eligible for Medicare coverage
• (Chronic obstructive pulmonary disease [COPD] subgroup only) >=1 diagnosis of COPD in any position during the Baseline period or on the index date

Greater than or equal to (>=1) diagnosis for cystic fibrosis, lung cancer, interstitial lung disease, or Alpha-1 antitrypsin deficiency during the Baseline period or on the index date

• Greater than or equal to (>=1) medical or pharmacy claim for mepolizumab, omalizumab, reslizumab, benralizumab, dupilumab, or tezepelumab during the Baseline period
• Less than (<) 3 months continuous clinical activity following the index date o Because this study uses open claims with eligibility proxied at the quarterly level, this criterion ensures that participants have observable healthcare activity during the follow-up period
• Greater than or equal to (>=1) diagnosis for eosinophilic granulomatosis with polyangiitis (EGPA), hypereosinophilic syndrome (HES), chronic rhinosinusitis with nasal polyps (CRSwNP), eosinophilic esophagitis (EOE), pulmonary eosinophilia, or atopic dermatitis during the Baseline period o These conditions are additional indications for one or more of the biologic therapies of interest. Excluding participants with these diagnoses ensures that biologic initiation reflects treatment for asthma rather than other Type 2 (T2) inflammatory or eosinophilic diseases, thereby improving comparability across cohorts