Relationship between the characteristics of hospitalised acute asthma patients and the severity of their asthma. A case-control study.

BACKGROUND The EAGLE project database was analysed to assess the characteristics of patients with severe (SA) who required hospitalisation as a result of an acute episode during the period 1994-2004, and the relationship with asthma severity. METHODS A total od 2593 clinical records corresponding to an equal number of patients hospitalised for acute asthma (15-69 years), with sufficient information to characterize their asthma severity in agreement with GNA criteria were identified (727 patients with SA compared with 1866 patients with non-severe asthma). RESULTS Patients with SA were older, displayed a greater predominance of female asthmatics, lower antecedents of atopy, and a higher frequency of previous hospitalisations compared with non-severe asthmatics (86.1% vs. 50.5%, p< or = 0.01). Additionally, SA patients showed more severe exacerbations characterized by acidosis, significant spirometric deterioration, greater length of hospital stay (9.4 days vs. 7.0 days), as well as a higher frequency of intubation (16.8% vs. 2.1%), intensive care unit admission (11.3% vs.4.9%), cardiopulmonary arrest (5.5% vs. 1.3%), and asthma deaths (2.1% vs. 0.4%) (all < or = 0.01) compared wit non-severe patients. CONCLUSIONS This study suggests that SA patients have greater morbidity and a disproportionate need for health care as a result of more severe exacerbations. However, non-severe asthmatics can also still present acute severe episodes (although with a lower frequency) with risk of life.