Effectiveness of Gram-Negative Bacterial Infection Control Interventions: A Systematic Review and Business-Case Analysis

Background: As of 2007, the National Healthcare Safety Network (NHSN) reported that 32% of nosocomial infections in the US were caused by Gram-negative bacilli (GNB), and the trend is expected to increase. High rates of anti-microbial resistance and person-to-person transmission of GNB have highlighted the need for effective infection control interventions. Objective: We sought to provide a means of estimating the incidence rate reduction and financial impact expected from a GNB infection control intervention prior to its implementation. Methods: We conducted an investigation of published literature to assess the practicality of either hospital-wide or intensive care unit (ICU)-specific GNB infection control interventions. After an initial PubMed search yielding articles related to GNB infection control, we eliminated all those not meeting our pre-defined inclusion criteria. We considered only quasi-experimental GNB-intervention studies conducted in hospitals or adult ICUs in which the authors provided pre- and post-intervention infection rates as infections and/or positive clinical cultures per 1,000 patient-days. We then systematically reviewed and extracted data from all relevant studies and computed the infection rate-reduction as a percentage of the pre-intervention rate for each study. After aggregating these reductions into a summary statistic, we conducted a business-case analysis from a hospital's perspective to estimate cost thresholds for which yearly intervention costs would be offset by cost savings from bloodstream infections (BSIs) prevented per year, utilizing a pre-estimated cost of $18,432 per BSI. We then performed two-way sensitivity analysis varying the bed size and pre-intervention infection rates.    Results: We reviewed 304 studies produced by the key search. 13 were included in the final review based on inclusion criteria. The mean reduction in GNB rates attributable to the interventions was 61% (95% CI: 41% - 80%), corresponding to an overall infection rate reduction of 20% (95% CI: 13% - 26%). Using the NHSN mean BSI rate for ICUs of 1.1 per 1,000 patient days, a GNB intervention in  a 15-bed ICU resulting in a 20% rate reduction could be expected to save between $14,000 and $29,000 (95% CI) over a one-year period (Figure). A 700-bed hospital with a BSI rate of 0.33 (NHSN mean) could expect to save between $200,000 and $400,000. Conclusions: These data suggest that a strong business case can be made for implementing GNB infection control interventions in most situations, especially in larger ICUs and hospitals with high rates of GNB infection.