Economic Analysis of Infectious Disease Consultation for Staphylococcus aureus Bacteremia among Hospitalized Patients

Abstract

Importance: Staphylococcus aureus bacteremia is associated with a significant burden of mortality, morbidity, and health care costs. Infectious disease consultation may be associated with reduced mortality and bacteremia recurrence rates. Objective: To evaluate the cost-effectiveness of infectious disease consultation for Staphylococcus aureus bacteremia. Design, Setting, and Participants: In this economic evaluation, a decision-analytic model was constructed comparing infectious disease consult with no consult. The population was adult hospital inpatients with Staphylococcus aureus bacteremia diagnosed with at least 1 positive blood culture. Cost-effectiveness was calculated as deaths averted and incremental cost-effectiveness ratios. Uncertainty was addressed by plotting cost-effectiveness planes and acceptability curves for various willingness-to-pay thresholds. Costs and outcomes were calculated for a time horizon of 6 months. The analysis was performed from a societal perspective and included studies that had been published by January 2022. Interventions: Patients received or did not receive formal bedside consultation after positive blood cultures for Staphylococcus aureus bacteremia. Main Outcomes and Measures: The main outcomes were incremental difference in effectiveness (survival probabilities), incremental difference in cost (US dollars) and incremental cost-effectiveness ratios (US dollars/deaths averted). Results: This model included 1708 patients who received consultation and 1273 patients who did not. In the base-case analysis, the cost associated with the infectious disease consult strategy was $54137.4 and the associated probability of survival was 0.77. For the no consult strategy, the cost was $57051.2, and the probability of survival was 0.72. The incremental difference in cost between strategies was $2913.8, and the incremental difference in effectiveness was 0.05. Overall, consultation was associated with estimated savings of $55613.4/death averted (incremental cost-effectiveness ratio, -$55613.4/death averted). In the probabilistic analysis, at a willingness-to-pay threshold of $50000, infectious disease consult was cost-effective compared with no consult in 54% of 10000 simulations. In cost-effectiveness acceptability curves, the consult strategy was cost-effective in 58% to 73%) of simulations compared with no consult for a willingness-to-pay threshold ranging from $0 to $150000. Conclusions and Relevance: These findings suggest that infectious disease consultation may be a cost-effective strategy for management of Staphylococcus aureus bacteremia and that it is associated with health care cost-savings.