# P-31. Outcomes Associated with the 2024 Blood Culture Shortage at a Large Academic Medical Center

## TL;DR

A blood culture shortage in 2024 led to reduced testing at a large hospital, with minor effects on patient outcomes but significant shifts in where and how testing occurred.

## Contribution

This study is the first to analyze the clinical impact of blood culture shortages on outcomes like mortality and readmission in a large academic medical center.

## Key findings

- Blood culture positivity, mortality, and readmission rates declined slowly before and during the shortage.
- The restriction led to a significant decrease in blood culture use, particularly in the ED and one hospital site.
- Inpatient admission and the flagship hospital were key predictors of outcomes during the shortage.

## Abstract

The Infectious Diseases Society of America and American Society for Microbiology recommend 2–3 blood culture sets in adults with suspected bloodstream infection. In June 2024, a national shortage of BACTEC blood culture bottles led our institution, a large, urban academic medical center, to restrict blood cultures to one set per patient every 24 hours from June 26 to December 23, 2024. While other institutions have described stewardship efforts during the shortage, little is known about its impact on clinical outcomes. We conducted a retrospective, quasi-experimental analysis to evaluate these effects.

Characteristics of Encounters with ≥1 Blood Culture Set Obtained During the Pre-Shortage (December 24, 2023–June 25, 2024) and Shortage (June 25, 2024–December 23, 2024) Period

Characteristics of Encounters with ≥1 Blood Culture Set Obtained During the Pre-Shortage (December 24, 2023–June 25, 2024) and Shortage (June 25, 2024–December 23, 2024) Period

Association Between Changes in Main Outcomes, Blood Culture Shortage Period, and Covariates

Association Between Changes in Main Outcomes, Blood Culture Shortage Period, and Covariates

We analyzed hospitalizations and emergency department (ED) encounters with ≥1 blood culture from December 24, 2023 to December 23, 2024. Outcomes included blood culture positivity, in-hospital mortality or hospice discharge, and 30-day readmission. We used segmented regression models in an interrupted time series analysis to assess changes at the June 26, 2024 cutoff, adjusting for covariates.

We identified 24229 encounters with ≥1 blood culture. Patient characteristics were similar pre- and during-restriction, with decreased encounters with ≥1 blood culture in the ED and one hospital site during the restriction period (Table 1). All outcomes declined slowly prior to the shortage; only 30-day readmission had a minor slope increase during restriction (Table 2 and Figure 1A–C). Encounters with ≥1 culture decreased markedly (Figure 1D). Regression identified various sociodemographic predictors of outcomes (Table 2). Of note, inpatient admission and our institution’s flagship hospital, to which the other hospitals often refer patients for higher level of care, were associated with all outcomes (Table 2).

Blood culture restriction had marginal impact on outcomes but markedly reduced the number of cultures obtained and seemed to shift testing to inpatients and our flagship hospital. These shifts may have influenced outcomes as suggested by regression modeling, though this remains speculative without further study. Limitations include retrospective, single-center design and lack of other potential covariate data (e.g. patient comorbidities). Future work will also examine other key outcomes, including intensive care admission and length of stay.

All Authors: No reported disclosures