A Point Prevalence Survey of Antimicrobial Usage in New Brunswick Hospitals

Prevalence surveys are useful tools for assessing the appropriateness of antimicrobial therapy.

The primary objective was to assess patterns of antimicrobial utilization and appropriateness in New Brunswick hospitals. The secondary objective was to assess the impact of hospital size and the presence of a penicillin allergy label on antimicrobial appropriateness.

A point prevalence survey was conducted of inpatients taking 1 or more systemic antimicrobials during admission to hospitals in New Brunswick. A structured protocol and web-based data collection tool (National Antimicrobial Prescribing Survey) were used for this survey. Data regarding hospital size and presence of a penicillin allergy label were also collected. Antimicrobial utilization was assessed in terms of guideline compliance and appropriateness. Results were summarized descriptively. A χ² analysis was performed to describe secondary outcomes.

Ten hospitals participated, and a total of 2200 patients were admitted at the time of the survey. The overall prevalence of antimicrobial use was 22.7% (500/2200). A total of 648 antimicrobials were ordered. The most frequently prescribed antimicrobials by class were first-generation cephalosporins (14.0%, 91/648), third-generation cephalosporins (11.3%, 73/648), and piperacillin-tazobactam (10.2%, 66/648). The most common indications for antimicrobial therapy were respiratory tract infections (27.3%, 177/648), urinary tract infections (12.2%, 79/648), and intra-abdominal infections (11.4%, 74/648). Compliance with local or regional treatment guidelines, where applicable, was 66.2% (188/284). Provincially, 68.1% (441/648) of the antimicrobial orders were deemed appropriate. Larger centres had substantially higher rates of appropriateness (p < 0.001). The presence of a penicillin allergy label had no impact on appropriateness (p = 0.21).

Several opportunities for targeted interventions were identified to improve antimicrobial prescribing, including decreasing the use of broad-spectrum antimicrobials, increasing guideline compliance, and ensuring documentation of antimicrobial duration by prescribers.