Asthma Exacerbation Rates in Adults Are Unchanged Over a 5-Year Period Despite High-Intensity Therapy

Background: Few data exist regarding the natural history of asthma exacerbations over time. Objective: To evaluate the frequency and risk factors of asthma exacerbation occurrence over a 5-year period in a large cohort of adult patients with persistent asthma. Methods: Health insurance claims from the Truven Health MarketScan database were analyzed for 2543 patients who had full medical and drug claims for years 2006 to 2011, did not have co-occurring chronic obstructive pulmonary disease in the index year (2006), and were treated with high-dose inhaled corticosteroids and long-acting β2-agonists for at least 120 days ("high intensity" therapy) in the index year. A retrospective analysis was conducted to assess the pattern of severe exacerbations (encounter with health care system and steroid burst) over time and their associations with the other measures of health status. Results: Despite the use of high-intensity asthma therapy, there was only a small decrease in total asthma exacerbations over time, but no significant time trend for asthma hospitalizations. An exacerbation in the prior year increased the risk for exacerbations almost 8-fold, (odds ratio 7.8 [95% CI, 7.1-8.6]). A 50% increase in exacerbation risk (odds ratio 1.5 [95% CI, 1.4-1.6]) was associated with continued high-intensity treatment for the duration of the study. Patients with encounters of chronic obstructive pulmonary disease after the index year were at 60% increased risk of an exacerbation. Conclusions: This study showed that exacerbation rates forpatients with asthma in a real-world setting remained relatively constant over time, and continuous high treatment intensity wasnot associated with a substantially lower risk of exacerbations.