Infectious diseases consultation reduces 30-day and 1-year all-cause mortality for multidrug-resistant organism infections

Background. Multidrug-resistant organism (MDRO) infections are associated with high mortality and readmission rates. Infectious diseases (ID) consultation improves clinical outcomes for drug-resistant Staphylococcus aureus bloodstream infections. Our goal was to determine the association between ID consultation and mortality following various MDRO infections. Methods. This study was conducted with a retrospective cohort (January 1, 2006-October 1, 2015) at an academic tertiary referral center. We identified patients with MDROs in a sterile site or bronchoalveolar lavage/bronchial wash culture. Mortality and readmissions within 1 year of index culture were identified, and the association of ID consultation with these outcomes was determined using Cox proportional hazards models with inverse weighting by the propensity score for ID consultation. Results. A total of 4214 patients with MDRO infections were identified. ID consultation was significantly associated with reductions in 30-day and 1-year mortality for resistant S. aureus (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.36-0.63; and HR, 0.73, 95% CI, 0.61-0.86) and Enterobacteriaceae (HR, 0.41; 95% CI, 0.27-0.64; and HR, 0.74; 95% CI, 0.59-0.94), and 30-day mortality for polymicrobial infections (HR, 0.51; 95% CI, 0.31-0.86) but not Acinetobacter or Pseudomonas. For resistant Enterococcus, ID consultation was marginally associated with decreased 30-day mortality (HR, 0.81; 95% CI, 0.62-1.06). ID consultation was associated with reduced 30-day readmission for resistant Enterobacteriaceae. Conclusions. ID consultation was associated with significant reductions in 30-day and 1-year mortality for resistant S. aureus and Enterobacteriaceae, and 30-day mortality for polymicrobial infections. There was no association between ID consultation and mortality for patients with resistant Pseudomonas, Acinetobacter, or Enterococcus, possibly due to small sample sizes. Our results suggest that ID consultation may be beneficial for patients with some MDRO infections.