Researchers re-estimate annual deaths from multidrug-resistant infections
Infectious disease specialists from Washington University School of Medicine estimate that the number of deaths caused by multidrug-resistant organisms (MDROs) is more than six times higher than widely cited figures from the Centers for Disease Control and Prevention (CDC).
In a letter published in Infection Control and Hospital Epidemiology, the researchers looked at data on inpatient and outpatient deaths in 2010 and estimated that a minimum of 153,113 deaths that year were caused by MDRO infections, with a worst-case scenario of 162,044. That would make MDROs the third-leading cause of death in the United States in 2010. The CDC estimated in a 2013 report that drug-resistant infections are responsible for 23,000 deaths a year, but because hospital codes don't specify deaths caused by MDROs, the true burden remains uncertain.
The researchers based the number of inpatient deaths caused by MDROs—70,837—on a conservative estimate of inpatient deaths due to sepsis (34.4%, 245,960) and the reported rate of MDR pathogens in sepsis cases (28.8%). The numbers for outpatient deaths—82,276 to 91,207—was determined by estimating how many outpatients died from infections in 2010 (17% to 19% of all cases, or 285,680 to 316,690 deaths) and then assuming that 28.8% were caused by MDROs.
The authors of the letter say the estimates illustrate the need for better surveillance and reporting mechanisms for MDROs infections.
"With rampant overuse of antibiotics, establishment of MDRO breeding and transmission centers (long-term acute-care hospitals and nursing facilities), and increasing rates of iatrogenic immunosuppression, the population at risk for MDRO infections and the likelihood of drug resistance will continue to increase," they write. "To address this critical issue, establishing the burden of MDROs is crucial to guide research funding allocation."
Nov 22 Infect Control Hosp Epidemiol letter
Japanese ASP reduces use of broad-spectrum antibiotics, study finds
Japanese researchers report in Open Forum Infectious Diseases that an antimicrobial stewardship program (ASP) centered around post-prescription review with feedback (PPRF) was tied to a reduction in the use of broad-spectrum antibiotics and the average length of stay at a Tokyo hospital over 4 years.
The before-after study conducted at Tokyo Metropolitan Tama Medical Center evaluated the impact of the ASP on antimicrobial use, patient-related outcomes, and changes in antimicrobial resistance in the inpatient setting by comparing two periods—the pre-intervention period (April 2012 to March 2014) and the intervention period (April 2014 to March 2018). The main activity in the ASP was a once-weekly PPRF meeting focused on auditing patients who were on carbapenems and piperacillin-tazobactam for more than 72 hours. Antimicrobial use was expressed as days of therapy (DOT) per 1,000 patient-days (PD).
An interrupted time series analysis showed that the monthly average use of both carbapenems (from 17.33 DOT per 1,000 PD to 8.67) and piperacillin-tazobactam (25.43 DOT/1,000 PD to 20.95) was lower in the intervention period than in the pre-intervention period. But the change in slope for carbapenem use significantly diminished over the course of the intervention period (from -0.73 to -0.003 DOT/1,000 PD [P < 0.001]), and the change in slope for piperacillin-tazobactam did not reach statistical significance (-0.04 to -0.24 DOT/1,000 PD [P = 0.16]). Post-intervention use of narrower spectrum antimicrobials was higher, but only ampicillin-sulbactam use reflected a statistically significant change (+0.58 DOT/1,000 PD [P < 0.001]).
The analysis also found that the monthly average length of hospital stay declined by -0.04 days per month (P < .001) and antimicrobial costs declined by -37.4 USD/1,000 PD per month (P < .001). Few post-intervention changes in the incidence of drug-resistant organisms were observed.
The authors conclude, "While the trends in antimicrobial use seen in the current study failed to demonstrate statistical significance, the results do suggest that PPRF for broad-spectrum antimicrobials can contribute to a sustained reduction in the use of antimicrobials and conduce to a hospital-wide de-escalation in antimicrobial use without compromising patients’ clinical outcomes."
Nov 22 Open Forum Infect Dis abstract
Review: Stewardship studies lack quality
A comprehensive systematic review of studies on antimicrobial stewardship has found that the overall quality is low and has not improved over time, a team of Dutch and British researchers report in Clinical Microbiology and Infection.
For the study, the researchers searched for all studies evaluating antimicrobial stewardship interventions published from 1950 through 2017. All studies underwent full-text evaluation, with reviewers assessing studies based on pre-specified design quality features (including use of randomized research design, multiple centers, and external controls) and factors that may influence design choices (including clinical setting, age-group studied, and financial support received.)
In total, 825 studies were included for review; 205 were in the community setting and 620 were in the hospital setting. Studies in the community setting fulfilled a median of 5 of 10 quality features, while studies in hospital settings fulfilled 3 of 10 quality features; none of the studies fulfilled all 10 quality features. Community setting studies were more likely to use randomization (odds ratio [OR], 5.9; 95% confidence interval [CI], 3.8 to 9.2), external controls (OR, 5.6; 95% CI, 3.6 to 8.5), and multiple centers (OR, 10.5; 95% CI, 7.1 to 15.7). Most studies focused exclusively on process measures, with only 48% of all studies reporting clinical outcomes and only 23% reporting microbiologic outcomes. No improvement in quality design over time was observed.
The authors of the review say the findings will be used to formulate recommendations in a white paper that will "support investigators with key decisions, support funders assessing proposals for stewardship studies, and enhance the quality and impact of research in this crucial area."
Nov 23 Clin Microbiol Infect study