Use of Evidence-Based Care Processes Decreases Mortality among Veterans with Staphylococcus aureus Bacteremia
Staphylococcus aureus bacteremia (SAB) is common and frequently associated with poor outcomes. Largely observational evidence indicates specific care processes are associated with significantly improved outcomes for patients with SAB, including early source control, use of echocardiography to identify endocarditis, appropriate antibiotic prescribing, and consultation with infectious disease (ID) specialists to guide management. Treatment guidelines call for increased use of these evidence-based care processes; however, it is not known if there have been widespread increases in their use, or if evidence-based care processes have led to declines in SAB mortality. This cohort study sought to determine how increasing use of evidence-based care processes may have contributed to improving survival for Veterans with SAB. Using VA data, investigators identified 36,868 Veterans who were admitted to one of 124 VA hospitals with a first episode of SAB from 2003 to 2014. The primary outcome was 30-day all-cause mortality after first positive blood culture for SAB. Investigators also assessed the use of appropriate antibiotic therapy, echocardiography, and ID consultation.
- Mortality associated with S. aureus bacteremia declined significantly in VA hospitals, and a substantial portion of the declining mortality (57%) was attributable to increased use of evidence-based care processes. Further, mortality declined progressively as the number of care processes a patient received increased.
- Risk-adjusted mortality decreased from 24% in 2003 to 18% in 2014. Rates of appropriate antibiotic prescribing increased from 66% to 79%, echocardiography from 34% to 73%, and consultation with an infectious disease specialist from 37% to 68%.
The experience in VA demonstrates increasing application of these care processes can meaningfully improve survival for patients with SAB in routine healthcare settings. However, results also indicate there remains room for improvement in SAB outcomes through even greater use of evidence-based care processes. Although the use of evidence-based processes substantially improved over the study period, approximately half (48%) of VA patients did not receive all three processes in 2014.
- As in any observational study, there is potential for unmeasured confounding. Also, investigators relied on administrative data for diagnoses of comorbidities, which may be inaccurate and allow residual confounding.
- Investigators did not have detailed clinical data on sources of bacteremia, whether these sources were controlled, or on all sites of infection.
This study was funded by HSR&D. Drs. Goto, Schweizer, Vaughan-Sarrazin, Perencevich, Livorsi, and Ohl are part of HSR&D's Center for Comprehensive Access & Delivery Research and Evaluation (CADRE), Iowa City, IA.
Goto M, Schweizer M, Vaughan-Sarrazin M, Perencevich E, Livorsi D, Diekema D, Richardson K, Beck B, Alexander B, and Ohl M. Increasing Use of Evidence-Based Care Processes and Declining Mortality for Staphylococcus aureus Bacteremia in Veterans Health Administration Hospitals, 2013-2014. JAMA Internal Medicine. October 1, 2017;177(10):1489-97.