Impact of Nucala on ExacerbationsNucala

Trial description: While biologic medications for severe asthma may be costly, they have a unique place in therapy for severe uncontrolled subjects and may reduce the burden of disease for those subjects that remain refractory despite current therapy. It is important for payers, providers, subjects and other healthcare stakeholders to understand the effectiveness of these biologic medications in the real world setting. This is a retrospective observational analysis of administrative claims using the Optum Research Database (ORD). Using the claims data, subjects within commercial and Medicare Advantage health plans treated with mepolizumab will be identified during the identification period (ID period) from 01-January-2015 through 31-March-2017. The index date will be set as the date of first new prescription fill for mepolizumab in which there were no previous fill in the 12 months period prior to the new fill. Asthma-related exacerbations and exacerbation-related health care costs will be measured in the 12 month Baseline and the 12 month period following index date (follow-up period). Subject demographics and Baseline clinical characteristics will be measured in the 12 month period prior to index date, including index date (Baseline period). The primary objective of the study is to compare the changes in the total number of asthma exacerbations among subjects receiving mepolizumab in the year before initiating Nucala to the year after.