This article is more than 5 years old. Information may no longer be current.
Antibiotic spectrum index improves evaluation of stewardship program
Click Here to Manage Email Alerts
Research published in Infection Control & Hospital Epidemiology highlighted the usefulness of an antibiotic spectrum index, or ASI, to measure antimicrobial stewardship efforts in a St. Louis NICU.
The CDC recommends that antimicrobial stewardship programs measure antibiotic use in days of therapy (DOT) per 1,000 patient days, Alexandra C. Lahart, MD, a resident in the department of pediatrics at the Washington University School of Medicine in St. Louis, and colleagues noted. However, the researchers suggested that DOT may not account for changes in prescribing behavior because it does not account for the spectrum of antibiotics administered.
“Almost all very low-birth-weight (VLBW)” — less than 1,500 g — “infants in the NICU receive antibiotics,” the researchers wrote. “Although at high risk for infection, excess antibiotic exposure in this population has been associated with significant morbidity. Antimicrobial stewardship is challenging yet essential in the NICU, and changes in prescribing practices may not be adequately captured with a metric focused solely on the volume of antibiotics exposure.”
According to Lahart and colleagues, the NICU at St. Louis Children’s Hospital implemented an antimicrobial stewardship program in 2016 with interventions that included changing the empiric regimen for late-onset sepsis from vancomycin and gentamicin to oxacillin and gentamicin, as well as changing the empiric regimen for necrotizing enterocolitis from vancomycin, clindamycin and gentamicin to ampicillin and gentamicin with or without metronidazole for suspected perforation or necrosis. In addition, the standard antibiotic durations were defined for culture-negative sepsis (5 days), Bell’s stage 1, 2 and 3 necrotizing enterocolitis (2-3 days, 7 days and 10 days, respectively).
In a retrospective cohort study, Lahart and colleagues compared antibiotic use for VLBW infants receiving care before the initiative was implemented (from Jan. 1 to Dec. 3, 2014; n = 136), and after the initiative was in place (from Jan. 1 to Dec. 31, 2017; n = 144).
According to the researchers, all infants included in the 2014 cohort received antibiotics, whereas no antibiotic exposure was reported for 11.8% of infants in 2017. They reported that the total DOT per 1,000 patient days decreased 32% from 2014 to 2017 for infants receiving care (335.6 vs. 227.4; P < .001), and the total ASI per antibiotic days decreased from 7.63 to 5.97 during the study period (P < .001).
Further analyses suggested that DOT per 1,000 patient days was unchanged in infants with culture-confirmed late-onset sepsis or meningitis, and infants with Bell’s stage 2 necrotizing enterocolitis or higher and spontaneous intestinal perforation, whereas ASI per antibiotic days decreased significantly during the study period, Lahart and colleagues reported.
“In conclusion, our study has demonstrated the utility of the ASI/[antibiotic days] metric in capturing changes in antibiotic use that are not completely documented with the currently used, CDC recommended metric of DOT per 1,000 PD. We propose that the ASI/[antibiotic days] metric should be utilized in addition to DOT per 1,000 PD when evaluating the impact of antimicrobial stewardship interventions.” – by Katherine Bortz
Disclosures: The authors report no relevant financial disclosures.
Perspective
Back to Top
Andrea Green Hines, MD
Antimicrobial stewardship programs (ASPs) play a vital role in optimizing patient care and safety, but the metrics used to evaluate the impact of these programs are not well defined. Determining an ideal metric for measurement of an individual ASP’s impact or success is difficult because of the nature of the complex care associated with patients who have confirmed or suspected infections, as well as the often overwhelming effort needed to take metrics from the medical record and transform them into meaningful analyses and conclusions.
The most commonly used metric by ASPs, and the one recommended by the CDC, is DOT per 1,000 patient days. Although this metric considers volume of antimicrobial prescribing, it does not easily equate to patient-level impact and ASP success. In this study by Lahart and colleagues, a previously developed ASI was applied to a population of VLBW infants to assess its utility to evaluate the impact of antimicrobial stewardship interventions. Conducting antimicrobial stewardship efforts in this patient population is difficult because of their high risk for acquiring health care-associated infections, given their immature immune systems, high acuity of care as well as the frequency of invasive procedures and frequent evaluation for sepsis with subsequent initiation of empiric antibiotic therapy.
The authors demonstrated that the ASI captured the impact of antimicrobial stewardship on the spectrum of agents chosen despite similar use as measured by DOT per 1,000 patient days. This metric is an important addition to a limited array of metrics used by ASPs and will be useful in more comprehensively assessing the valuable work of these programs.
Read more about
Click Here to Manage Email Alerts