Canadian hospitals see significant decrease in antibiotic use

A major reduction in the use of fluoroquinolones has driven a 12% decrease in total antibiotic use in Canadian hospitals in recent years, according to a new study in Antimicrobial Resistance and Infection Control.

In the retrospective surveillance study, acute care hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) submitted annual data on all systemic antimicrobial use (AMU) from 2009 to 2016. National and regional rates of AMU were calculated and analyzed using defined daily doses per 1,000 patient-days (DDD/1,000 pd), and AMU data were used to rank the top antimicrobial agents used individually, by class/subclass, and by year. Overall, 16 to 18 CNISP adult hospitals per year provided data, with representation from 6 sites in western Canada, 15 in central Canada, and 1 in eastern Canada.

From 2009 to 2016, the data showed a 12% reduction in total AMU (from 654 to 573 DDD/1,000 pd, P = 0.03). Fluoroquinolones accounted for most of this decrease, with a 47% reduction in combined oral and intravenous use, (from 129 to 68 DDD/1,000 pd, P < 0.002). The top five antimicrobials used in 2016 were cefazolin (78 DDD/1,000 pd), piperacillin-tazobactam (53 DDD/1,000 pd), ceftriaxone (49 DDD/1,000 pd), vancomycin (combined oral and intravenous use: 44 DDD/1,000 pd), and ciprofloxacin (combined oral and intravenous use: 42 DDD/1,000 pd).

Among the top 10 antimicrobials used in 2016, ciprofloxacin and metronidazole use decreased significantly between 2009 and 2016, by 46% (P = 0.002) and 26% (P = 0.002) respectively. Use of ceftriaxone (85% increase, P = 0.0008) and oral amoxicillin-clavulanate (140% increase, P < 0.0001) increased significantly but contributed only a small component (8.6% and 5.0%, respectively) of overall use.

The authors of the study say it's unclear whether the reduction in fluoroquinolone use is related to stewardship efforts, warnings of adverse effects associated with fluoroquinolone use in the United States and Canada, or a combination.
Feb 13 Antimicrob Resist Infect Control study

Electronic alerts linked to fewer C diff tests, lower rates, review finds

A systematic review of 11 studies indicates that the use of electronic alerts for diagnostic stewardship for Clostridioides difficile infection (CDI) was associated with reductions in CDI testing, inappropriate CDI testing, and rates of CDI, researchers reported in Clinical Infectious Diseases.

The aim of the study was to determine whether CDI testing-oriented electronic alerts, which aim to discourage inappropriate testing and subsequent unnecessary antibiotic treatment, have an effect not just on process indicators, such as laboratory ordering, but also on intermediate outcomes (rates of CDI testing and inappropriate testing) and patient-centered outcomes (rates of CDI).  To answer those questions, the researchers searched six databases for studies evaluating the association between the alerts and CDI testing volume and/or CDI rate.

The 11 studies that met the criteria for inclusion varied significantly in alert triggers and study outcomes. Nine studies used an alert discouraging CDI testing when the patient had recent laxative use, 7 used an alert discouraging CDI testing with lack of clinical indication for testing, and 6 used an alert discouraging CDI testing when the patient had recent CDI testing; 11 articles studied the number of tests ordered, 6 studied the number of appropriate tests, and 7 studied the CDI rate.

Six of the 11 studies demonstrated a statistically significant decrease in CDI testing volume, 6 of 6 studies evaluating appropriateness of CDI testing found a significant reduction in the proportion of inappropriate testing, and 4 of 7 studies measuring CDI rate demonstrated a significant decrease in the CDI rate in the post- vs pre-intervention periods. The magnitude of the increase in appropriate CDI testing varied, with some studies reporting an increase with minimal clinical significance.

The authors of the review note that, while alert-based interventions appeared to be largely successful in achieving the desired changes, most studies included multiple co-interventions, and none were randomized. In addition, they point out that unintended adverse consequences, such as underdiagnosis or delayed diagnosis of CDI, and alert fatigue—in which physicians have trouble distinguishing between clinically meaningful and non-meaningful alerts—remain understudied.
Feb 15 Clin Infect Dis abstract