Reduced mortality in cystic fibrosis patients treated with tobramycin inhalation solution.

BACKGROUND

Though tobramycin inhalation solution has been used for over a decade to improve lung function and reduce exacerbations in patients with cystic fibrosis (CF), its effects on mortality have not been well-described. This study aimed to assess the association between use of tobramycin inhaled solution and mortality in patients with CF and chronic Pseudomonas aeruginosa (PA) infection.

METHODS

Longitudinal logistic regression was used to assess the association between current-year reported use of tobramycin inhalation solution and subsequent-year mortality of patients meeting recommended criteria for tobramycin inhalation solution use in the United States Cystic Fibrosis Foundation's Patient Registry (1996-2008).

RESULTS

Among 12,740 patients meeting inclusion criteria, 2,538 deaths were observed during a median follow-up of 6 years. After regression adjustment, use of tobramycin inhaled solution was associated with a 21% reduction in the odds of subsequent year mortality (odds ratio (95% CI): 0.79 (0.72-0.88), P < 0.001). In our model, use of dornase alfa was also associated with a 15% reduction in the odds of subsequent year mortality (odds ratio (95% CI): 0.85 (0.76-0.95), P = 0.005). Underweight for age, CF-related diabetes, female gender, worse lung function and cultures positive for Pseudomonas aeruginosa or Burkholderia cepacia complex, among multiple other patient characteristics, were associated with significantly increased mortality. Adjusted mortality rates for patients reporting tobramycin inhalation solution use in all versus none of the follow-up years were 1.3% versus 2.1% at 2 years, 5.2% versus 8.0% at 5 years, and 9.9% versus 15.0% at 10 years.

CONCLUSION

After adjustment for multiple patient characteristics and known risk factors, use of tobramycin inhalation solution was associated with significantly reduced mortality among patients with CF.