# Changes in Access to Comprehensive Clinical Microbiology Laboratory Testing in Tennessee From 2019–2024

## TL;DR

This study shows a significant decline in access to comprehensive microbiology labs in Tennessee from 2019 to 2024, especially in rural and low-income areas.

## Contribution

The study quantifies geographic and demographic changes in access to clinical microbiology labs in Tennessee over five years.

## Key findings

- The number of Tier 1 microbiology labs in Tennessee dropped by 38% from 2019 to 2024.
- Lab closures were linked to rurality, lower income, higher poverty, and less education.
- The decline reduced coverage by 35%, affecting access in at-risk communities.

## Abstract

Timely clinical microbiology laboratory testing is crucial for effective infectious disease management, impacting antibiotic selection, patient outcomes, and health care costs. This study aimed to evaluate changes in geographic access to comprehensive (Tier 1) clinical microbiology laboratories in Tennessee between 2019 and 2024.

With the help of the Tennessee Department of Health, Tier 1 microbiology laboratories in Tennessee were identified for both 2019 and 2024. Catchment areas were calculated using a 25-mile drive-time radius around each laboratory. Changes in the number and location of Tier 1 laboratories were quantified, and demographic data were compared between laboratories that stayed open and those that closed.

The number of Tier 1 microbiology laboratories in Tennessee decreased by 38% over the 5-year period, and this resulted in a 35% decrease in square-mile coverage across the state. Covariates associated with laboratory closure included rurality, lower income, higher poverty, race, higher disability, and less education.

A substantial decline in the number of Tier 1 clinical microbiology laboratories in Tennessee between 2019 and 2024 has decreased local access to comprehensive testing in areas with at-risk patient populations. This may have implications for timely diagnosis, appropriate antimicrobial therapy, and, ultimately, patient outcomes. Further research is needed to evaluate the clinical and economic consequences of these changes in laboratory access.