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.