Is secondhand smoke exposure associated with increased exacerbation severity among children hospitalized for asthma?

OBJECTIVE To determine the association between secondhand smoke (SHS) exposure and length of stay (LOS) and other exacerbation severity indicators in children hospitalized for asthma. METHODS We conducted a retrospective chart review at 2 children's hospitals. Patients aged 2 to 18 hospitalized for asthma in 2012 were included. Outcome variables included LOS, PICU, magnesium, and intravenous (IV) steroids. Bivariate analysis determined differences between SHS-exposed and non-SHS-exposed groups. Geometric means were used for LOS to account for skewed distribution. Logistic and zero-truncated negative binomial regression models were used to determine the independent association between SHS exposure and hospitalization severity indicators. RESULTS A total of 623 patients were included; 41% reported SHS exposure. Mean LOS was 47.5 hours. In the SHS-exposed group, LOS was 50.0 (95% confidence interval [CI] 46.7-54.0) and in the nonexposed group it was 45.8 (95% CI 43.4-48.4) (P = .02). In regression analysis, institution modified the effect of SHS exposure on LOS. At Children's Hospital Colorado, SHS exposure was associated with a 20% increase in LOS (incidence rate ratio 1.2, 95% CI 1.1-1.3). At the Medical University of South Carolina, there was no significant association. SHS-exposed patients were more likely to receive IV steroids (odds ratio 1.6, 95% CI 1.1-2.3) CONCLUSIONS: Among children hospitalized for asthma, we identified a significant association at 1 institution between SHS exposure and LOS and found that IV steroid use was significantly associated with LOS at both institutions. Eliminating SHS exposure among children with asthma is important.