Antibiotic susceptibility reporting and association with antibiotic prescribing: a cohort study

Bradley J Langford; Nick Daneman; Christina Diong; Alex Marchand-Austin; Kwaku Adomako; Arezou Saedi; Kevin L Schwartz; Jennie Johnstone; Derek R MacFadden; Larissa M Matukas; Samir N Patel; Gary Garber; Kevin A Brown

doi:10.1016/j.cmi.2020.10.001

Antibiotic susceptibility reporting and association with antibiotic prescribing: a cohort study

Clin Microbiol Infect. 2021 Apr;27(4):568-575. doi: 10.1016/j.cmi.2020.10.001. Epub 2020 Oct 12.

Authors

Affiliations

¹ Public Health Ontario, Hotel Dieu Shaver Health and Rehabilitation Centre, Ontario, Canada. Electronic address: Bradley.Langford@oahpp.ca.
² Public Health Ontario, Sunnybrook Health Sciences Center, ICES, Institute of Health Policy Management and Evaluation, University of Toronto, Canada.
³ ICES, Ontario, Canada.
⁴ Public Health Ontario, Infection Prevention and Control, Canada.
⁵ Public Health Ontario, ICES, Dalla Lana School of Public Health, Canada.
⁶ Public Health Ontario, Sinai Health System, Dalla Lana School of Public Health, Canada.
⁷ Ottawa Hospital Research Institute, Canada.
⁸ Unity Health Toronto, University of Toronto, Department of Laboratory Medicine and Pathobiology, Canada.
⁹ Public Health Ontario, University of Toronto, Department of Laboratory Medicine and Pathobiology, Canada.
¹⁰ Public Health Ontario, University of Toronto, University of Ottawa, Ottawa Research Institute, Canada.

PMID: 33059090
DOI: 10.1016/j.cmi.2020.10.001

Abstract

Objective: Selective reporting of antibiotic susceptibility test results may help guide appropriate antibiotic prescribing, particularly for urinary tract infections. Our objective was to describe laboratory urine culture susceptibility reporting practices and to estimate their impact on antibiotic prescribing in outpatients.

Methods: We examined all positive urine cultures with Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis associated with an antibiotic prescription among outpatients over 65 years of age in Ontario, Canada from 2014 through 2017. We evaluated antibiotic prescribing in the empirical window (1-3 days before culture result) and in the directed window (0-5 days after culture result). Unadjusted and adjusted odds ratios were reported to estimate the association between reporting and prescribing.

Results: In total 113 780 eligible urine cultures from 48 laboratories were included in the study cohort. Susceptibility reporting practices were highly variable between laboratories, with a range across antibiotics from norfloxacin (n = 5/48, 10.4% reporting) to nitrofurantoin (n = 40/48, 83.3% reporting). Reporting antibiotic susceptibility was associated with increased odds of prescribing that antibiotic in the directed window (aOR 2.98, 95%CI 2.07-4.28). At the laboratory level, the proportion of urine cultures reporting specific antibiotic susceptibility results was also associated with an increase in prescribing of that antibiotic in the empirical window (adjusted OR 1.23, 95%CI 1.13-1.33, per 25% increase in reporting).

Conclusions: Laboratory reporting of antibiotic susceptibility results for urine cultures is associated with empirical and directed prescribing of the reported antibiotics. Laboratories can play an important role in guiding appropriate antibiotic selection for urinary indications.

Keywords: Antibiotic prescribing; Antibiotic susceptibility testing; Antimicrobial stewardship; Microbiology laboratory; Selective reporting.

MeSH terms

Aged
Aged, 80 and over
Anti-Bacterial Agents / administration & dosage*
Anti-Bacterial Agents / pharmacology*
Cohort Studies
Drug Prescriptions*
Drug Resistance, Bacterial*
Female
Humans
Male
Odds Ratio
Risk Factors
Urinary Tract Infections / drug therapy*
Urinary Tract Infections / microbiology

Substances

Anti-Bacterial Agents