Human Antimicrobial Drug Use Report 2012/2013

Contributors

These acknowledgements are intended to identify and thank the people that have contributed to the success of this report.

Human Antimicrobial Use Surveillance Lead
Rita Finley ¹

Authors / Analysts
Kahina Abdesselam ²
Rita Finley
Shiona Glass-Kaastra ¹

Reviewers
John Conly, University of Calgary
Diana George, British Columbia Centres for Disease Control (BCCDC)
Jim Hutchinson, University of British Columbia
Fawziah Marra, University of British Columbia
Warren McIsaac, Mt. Sinai Hospital
David Patrick, University of British Columbia, British Columbia Centres for Disease Control (BCCDC)
Lynora Saxinger, University of Alberta Hospital
Daniel Thirion, University of Montreal
Karl Weiss, University of Montreal

¹ Centre for Food-borne, Environmental, and Zoonotic Infectious Diseases

² Centre for Communicable Diseases and Infection Control

Executive Summary

In 2013, office-based physicians saw patients for more than 293 million diagnoses, resulting in 23.8 million antimicrobial recommendations (8% of all diagnoses). A total of 22.8 million antimicrobial prescriptions were dispensed through pharmacies representing 202,000 kilograms of active ingredient. Pneumonia and acute sinusitis had the highest percentage of all diagnoses resulting with an antimicrobial recommendation (85% and 84%, respectively). Children between the ages of 3 and 9 years had the highest percentage of diagnoses with an antimicrobial recommendation, consisting mostly of penicillins or macrolides. Over time, the greatest changes in antimicrobial recommendations were observed among pneumonia diagnoses (9% increase), upper urinary tract infection/pyelonephritis (13% decrease), chronic sinusitis (6% decrease) and acne (6% decrease).

Overall levels of prescriptions and costs associated with antimicrobials dispensed through community pharmacies have decreased consistently since 2011. Although the most commonly prescribed antimicrobials for 2013 were amoxicillin, ciprofloxacin and azithromycin, prescription rates for nitrofurantoin, moxifloxacin and azithromycin have shown dramatic changes between 2000 and 2013. Overall prescription rates for oral antimicrobials have not shown dramatic changes between 2010 and 2013 while increases have been seen in the volume of parenteral products dispensed through outpatient pharmacies. However, the volume of antimicrobials for parenteral administration remained low relative to the volume of oral products; in 2013 there were more than 260 oral prescriptions dispensed for each parenteral antimicrobial prescription at the national level. Between 2012 and 2013, total kilograms of active ingredient and costs for parenteral products have increased by 200% and 96%, respectively, driven mainly by increases in cefazolin and piperacillin-tazobactam products.

Over time, patterns in outpatient antimicrobial use decreased with increasing age among children and young adults. In contrast, levels of use increased as age increased among adults. In 2013, antimicrobial use was highest among the youngest (0-5 years) and oldest (65+) age groups with the youngest (0 to 5 years) group having observed the greatest prescription rate decline between 2010 and 2013. However, in 2013, levels of use in children between 0 and 5 years was 30% (230 prescriptions/1,000 inhabitants) more than what was observed in the general population (872 compared to 642 prescriptions/1,000 inhabitant). In contrast, prescriptions for the 12-17 age group was 30% (220 prescriptions/1,000 inhabitants) lower than the overall rate. Levels of use among people 40 years of age or older were found to be slightly higher while those 18 to 39 age group had slightly lower use than the overall national levels.

Regional differences were observed in the diagnoses and antimicrobial recommendation rates, as well as overall levels of use and cost associated with antimicrobial prescriptions. The province of Newfoundland and Labrador displayed the highest levels of use for all measures, with use 30% higher than that reported for the second highest province (Saskatchewan). Prescription rates for parenteral antimicrobials in the provinces of Québec, New Brunswick, and Nova Scotia were more than fifteen times the rates reported in the provinces of Ontario, British Columbia and Manitoba. Looking at specific antimicrobials, Newfoundland and Labrador had the lowest levels of use for vancomycin, while Québec had the highest use for cefadroxil, cefprozil, ertapenem, minocycline, moxifloxacin, penicillin v and vancomycin. In the community setting in all provinces with the exception of New Brunswick and Nova Scotia, the dispensing of oral vancomycin was roughly 50% greater than the dispensing of parenteral vancomycin. In New Brunswick and Nova Scotia, this was reversed. In the hospital setting, only parenteral vancomycin products were purchased.

Total kilograms of active antimicrobial ingredients purchased by hospitals increased 75% between 2010 and 2013, driven mainly by increased purchases of ceftriaxone and piperacillin and enzyme inhibitor products. In contrast with what was observed with pharmacy dispensations, the volume of parenteral antimicrobials was 9 times that of oral antimicrobials purchased in the hospital. There were large variations in hospital purchasing among the provinces; the proportion of parenteral products purchased ranged from 85% in Saskatchewan to 94% in New Brunswick. The total mass of active ingredient purchased by hospitals was highest in Manitoba and lowest in Québec, while the cost was lowest in Ontario and highest in British Columbia. The higher levels of purchased antimicrobials in Manitoba was due to ceftriaxone purchasing; Manitoba reported purchasing 40% more product than any other province based on defined daily doses/1,000 inhabitant-days. Piperacillin and enzyme inhibitor products ranked high in the total kilogram of active antimicrobial ingredients per 1,000 inhabitants among all provinces with the exception of British Columbia, where ceftriaxone was the highest mass of active ingredient purchased.

Antimicrobial use information is presented in this report for better understanding trends over time at the national and provincial levels. However, it is important when interpreting this information to have full understanding of any changes that have taken place on infectious disease rates as well as formularies at the provincial and hospital levels. These changes could drive some of the trends presented in this report.

Table of Contents

• Contributors
• Executive Summary
• List of Figures
• List of Tables
• Preamble
• What's New in the 2012/2013 Report
• Important Notes
  • Abbreviations of Provinces/Regions
  • General Abbreviations

1. Physician Diagnosis Data

   National Diagnosis Data
   • Antimicrobial recommendations by diagnostic class
   • Recommendations by age group and gender
   • Recommendations by region

2. Pharmacy Dispensation Data

   National Utilization
   • Overall measures of use
   • Use by age groups
   • Use at the individual drug level
   • Use by route of administration
   Provincial Variation
   • Overall measures of use
   • Use at individual drug level
   • Use by route of administration

3. Hospital Purchasing Data

   National Purchasing
   • Overall measures
   • Individual drug purchasing
   • Purchasing by route of administration
   Provincial Purchasing
   • Overall measures
   • Individual drug purchasing
   • Purchasing by route of administration

• Appendix A - Methods for Data Collection and Analysis
  • Physician Diagnosis Data
  • Pharmacy Dispensation Data
  • Hospital Purchasing Data
  • Population sizes used for analysis of all datasets.
• Appendix B – Additional Physician Diagnosis Data
• Appendix C – Additional Pharmacy Dispensation Data
• Appendix D – Additional Hospital Purchasing Data