The relationship of rhinovirus-associated asthma hospitalizations with inhaled corticosteroids and smoking

Background. Although rhinovirus ( RV) respiratory infections trigger asthma exacerbations, the etiologic association between this virus and severe exacerbations, as well as the clinical characteristics of adults at risk for RV-associated asthma that necessitates hospitalization, have not been established. Methods. During 1999 - 2003, we conducted a cohort study of 101 adults prospectively enrolled at hospital admission for an asthma exacerbation. Patient characteristics and frequencies of RV in nasal specimens were analyzed, by reverse-transcription polymerase chain reaction (RT-PCR), at asthma-related hospital admission and at a 3-month convalescent follow-up visit. Results. RV was detected by RT-PCR in 21% of hospitalized patients over a 4-year period and in 1.3% of patients who returned for a 3-month follow-up visit. RV detection was strongly associated with hospitalization for asthma ( adjusted odds ratio [ OR], 15.1 [ 95% confidence interval {CI}, 1.88-121.4]). After adjustment for baseline asthma severity, RV-positive patients were more likely than RV-negative patients to be current smokers and nonusers of inhaled corticosteroids (ICSs) ( adjusted OR, 11.18 [ 95% CI, 2.37 - 52.81]; P = .0002). Conclusions. RV respiratory infection is an etiologic agent in severe asthma exacerbations necessitating hospitalization in adults. Compared with hospitalized patients with asthma who were RV negative, RV-positive patients were significantly more likely to be smokers and nonusers of ICSs.