Evidence-based care for S. aureus bacteremia reduced mortality in hospitalized veterans

The use of appropriate antibiotics, echocardiography, and infectious disease consults for patients with Staphylococcus aureus bacteremia increased significantly from 2003 to 2014.

Increases in the use of appropriate antibiotics, echocardiography, and infectious disease (ID) consults were associated with significant decreases in mortality from Staphylococcus aureus bacteremia (SAB), a recent study found.

The retrospective study included all patients admitted to Veterans Health Administration acute care hospitals with a first episode of SAB from 2003 through 2014. From 124 hospitals, there were a total of 36,868 patients (mean age, 66.5 years; 97.7% male); 52.4% had methicillin-resistant infections and 47.6% had methicillin-susceptible infections. The primary outcome was 30-day all-cause mortality. Results were published online Sept. 5 by JAMA Internal Medicine.

Risk-adjusted mortality in the SAB patients decreased from 23.5% in 2003 to 18.2% in 2014. In the same period, rates of the three evidence-based care processes examined by the study all increased. Appropriate antibiotic prescribing increased from 66.4% to 78.9%. Echocardiography increased from 33.8% to 72.8%. ID consultation increased from 37.4% to 68.0%. After adjustment for patient characteristics, cohort year, and other care processes, receipt of each of the care processes was found to be associated with lower 30-day mortality (adjusted odds ratios, 0.74 [95% CI, 0.68 to 0.79] for antibiotics, 0.73 [95% CI, 0.68 to 0.78] for echocardiography, and 0.61 [95% CI, 0.56 to 0.65] for ID consults). Mortality risk decreased progressively as patients received more processes (adjusted odds ratio for all three compared with none, 0.33; 95% CI, 0.30 to 0.37).

The study authors concluded that mortality associated with SAB decreased significantly in the studied hospitals, and they estimated that 57.3% of the drop in mortality could be attributed to the increased use of the three studied care processes. However, the results “also indicate that opportunity remains for improvement in SAB outcomes through even great use of evidence-based care processes,” the authors wrote, noting that 47.8% of the patients still did not receive all three processes in 2014.

“Given this evidence and the high prevalence of SAB, hospitals that do not routinely apply these evidence-based practices should prioritize quality improvement programs that address SAB management,” they said.

The study was limited by the risk of unmeasured confounding. Other studies have shown decreasing mortality from other conditions in Veterans Health Administration hospitals over the same time period, which could suggest secular trends toward lower mortality, the authors said. However, adjusted models suggested this was not the explanation for the findings and rather, the improvement in SAB processes and outcomes could help explain decreases in mortality in these hospitals, according to the authors.