The Burden of Severe Asthma in France: A Case-Control Study Using a Medical Claims Database.

Background: Severe asthma (SA) is defined by treatment intensity. The availability of national databases allows accurate estimation of the prevalence, long-term outcomes, and costs of SA.

Objective: To provide accurate information on SA, focusing on comorbidities, mortality, health care resource consumption, and associated costs.

Methods: A cohort of patients with SA identified in 2012 was extracted from a French representative claims database and followed for 3 years. Their characteristics, comorbidities, mortality, and direct costs were compared with a matched control group without asthma.

Results: A total of 690 patients with SA were matched to 2070 patients without asthma (mean age, 61 years; 65.7% women). The prevalence of SA was estimated to be 0.18% to 0.51% of the French adult population. Comorbidities were more frequent in patients with SA (73.9% suffered from cardiovascular disease vs 54.3% in controls; P < .001). A total of 58.7% of patients with SA used oral corticosteroids (OCS) in 2012 with a mean intake of 3.3 boxes/year/patient and 9% received ≥6 dispensings of OCS. A total of 6.7% were treated by omalizumab. Patients with SA were more frequently hospitalized (33.2% vs 19.7%; P < .001), more frequently consulted a general practitioner (97.8% vs 83.9%; P < .001) (9.8 ± 6.8 vs 6.2 ± 5.3 consultations/year; P < .001), and 31% have consulted a private respiratory physician. Compared with controls, 3-year cumulative mortality was higher in SA (7.1% vs 4.5%; P = .007). Direct medical cost was $9227 versus $3950 (P < .001) mostly driven by medication costs.

Conclusions: The prevalence of SA in the French adult population is at least 18 of 10,000. Burden of disease is high with respect to comorbidities, mortality, and asthma-related health care resource use.