Factors associated with overall and attributable mortality in invasive aspergillosis

Invasive aspergillosis is associated with high death rates. Factors associated with increased mortality have not yet been identified in a large population of patients with various underlying conditions.

We retrospectively reviewed 385 cases of suspected or documented aspergillosis that occurred during a 9-year period. We identified 289 episodes that fulfilled the criteria for possible, probable, or proven invasive aspergillosis according to the international definition criteria and that was treated with an anti-Aspergillus active antifungal drug. Clinical and microbiological variables were analyzed for their effects on overall and attributable mortality. Significant variables in univariate analysis were introduced into a multivariate Cox model.

Twelve-week overall and disease-specific survival rates were 52.2% (95% confidence interval, 46.5%-57.9%) and 59.8% (95% confidence interval, 54.0%-65.4%), respectively. Receipt of allogeneic hematopoietic stem cell or solid-organ transplant, progression of underlying malignancy, prior respiratory disease, receipt of corticosteroid therapy, renal impairment, low monocyte counts, disseminated aspergillosis, diffuse pulmonary lesions, pleural effusion, and proven or probable (as opposed to possible) aspergillosis are predictors of increased overall mortality. Similar factors are also predictors of increased attributable mortality, with the following exceptions: pleural effusion and low monocyte counts have no impact, whereas neutropenia is associated with a higher attributable mortality.

Identification of predictors of death helps in the identification of patients who could benefit from more-aggressive therapeutic strategies. Initiation of therapy at the stage of possible infection improves outcome, and this finding calls for the development of efficient preemptive strategies to fill the gap between empirical and directed therapy.