# Post-Exposure Prophylaxis Prescribing Practices in a Lyme Disease-Endemic Area

## TL;DR

This study examines how often doctors follow Lyme disease prevention guidelines when prescribing doxycycline after tick bites in a high-risk area.

## Contribution

The study provides new insights into real-world adherence to IDSA Lyme disease prophylaxis guidelines in a rural, endemic region.

## Key findings

- 44% of prescriptions were for adults aged 65–79, and 66% for rural residents.
- Only 12% of prescriptions were clearly indicated per guidelines, with poor documentation in most cases.
- Prescribing peaked in spring and summer, aligning with tick activity patterns.

## Abstract

Background/Objectives: The 2020 Infectious Diseases Society of America (IDSA) guidelines recommend a single 200 mg dose of doxycycline within 72 h of tick removal after a high-risk bite for Lyme disease prophylaxis. However, limited data are available on prescribing practices related to this recommendation in highly endemic Lyme disease areas. Methods: We conducted a retrospective chart review on adult patients (aged ≥ 18 years) who received a single dose of oral doxycycline for Lyme disease prevention for the period 2022–2024 within a rural Wisconsin health system. Patient and provider prescribing characteristics were evaluated. Manual data abstraction was performed on a random sample of 155 prescribing events to assess adherence to IDSA guidelines. Results: A total of 2404 prophylaxis prescriptions were identified; 44% were prescribed to older adults between 65 and 79 years of age, 54% were prescribed to males, and 66% were prescribed to patients living in rural areas. Prescriptions peaked in spring and summer months, consistent with the known seasonal trends in tick activity. Prescribing was distributed relatively evenly across provider types, with the majority (77%) of cases occurring in outpatient and urgent care settings. Upon manual abstraction, doxycycline was indicated in 12% with the remainder either classified as possibly indicated or not indicated due to suboptimal documentation and nonadherence. Conclusions: Our study identified high rates of incomplete documentation and uncertainty in guideline concordance in a Lyme-endemic health system, highlighting the opportunities to support evidence-based prescribing and to improve documentation practices.