The Effect of COVID-19 Vaccination on Outpatient Antibiotic Prescribing in Older Adults: A Self-Controlled Risk-Interval Study

Clin Infect Dis. 2024 Aug 16;79(2):375-381. doi: 10.1093/cid/ciae182.

Abstract

Background: Coronavirus disease 2019 (COVID-19) vaccination has been associated with reduced outpatient antibiotic prescribing among older adults with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We assessed the impact of COVID-19 vaccination on outpatient antibiotic prescribing in the broader population of older adults, regardless of SARS-CoV-2 infection status.

Methods: We included adults aged ≥65 years who received their first, second, and/or third COVID-19 vaccine dose from December 2020 to December 2022. We used a self-controlled risk-interval design and included cases who received an antibiotic prescription 2-6 weeks before vaccination (pre-vaccination or control interval) or after vaccination (post-vaccination or risk interval). We used conditional logistic regression to estimate the odds of being prescribed (1) any antibiotic, (2) a typical "respiratory" infection antibiotic, or (3) a typical "urinary tract" infection antibiotic (negative control) in the post-vaccination interval versus the pre-vaccination interval. We accounted for temporal changes in antibiotic prescribing using background monthly antibiotic prescribing counts.

Results: 469 923 vaccine doses met inclusion criteria. The odds of receiving any antibiotic or a respiratory antibiotic prescription were lower in the post-vaccination versus pre-vaccination interval (aOR, .973; 95% CI, .968-.978; aOR, .961; 95% CI, .953-.968, respectively). There was no association between vaccination and urinary antibiotic prescriptions (aOR, .996; 95% CI, .987-1.006). Periods with high (>10%) versus low (<5%) SARS-CoV-2 test positivity demonstrated greater reductions in antibiotic prescribing (aOR, .875; 95% CI, .845-.905; aOR, .996; 95% CI, .989-1.003, respectively).

Conclusions: COVID-19 vaccination was associated with reduced outpatient antibiotic prescribing in older adults, especially during periods of high SARS-CoV-2 circulation.

Keywords: COVID-19 vaccines; antibiotic prescribing; antibiotic stewardship; older adults.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents* / administration & dosage
  • Anti-Bacterial Agents* / therapeutic use
  • COVID-19 Vaccines* / administration & dosage
  • COVID-19* / prevention & control
  • Drug Prescriptions / statistics & numerical data
  • Female
  • Humans
  • Male
  • Outpatients / statistics & numerical data
  • Practice Patterns, Physicians' / statistics & numerical data
  • SARS-CoV-2* / immunology
  • Vaccination / statistics & numerical data

Substances

  • Anti-Bacterial Agents
  • COVID-19 Vaccines