QUARTZ: Comparative Effectiveness of Switching From Albuterol to Albuterol/Budesonide Versus Adding Low-dose ICS or LTRA to Albuterol

The QUARTZ study is a retrospective observational cohort study using a prevalent new-user design and U.S. healthcare claims data to evaluate treatment effectiveness among patients with asthma. The study compares the real-world effectiveness of switching from albuterol-only rescue therapy to albuterol/budesonide versus adding low-dose inhaled corticosteroids (ICS) or leukotriene receptor antagonists (LTRA) while continuing albuterol. The primary objective is to assess the comparative effectiveness of these treatment strategies in reducing severe asthma exacerbations in routine clinical practice in the United States.