# Low diagnostic yield of repeat urine cultures in hospitalized patients at a tertiary center in Northern California, 2023–2024

## TL;DR

Repeat urine cultures in hospitalized patients often provide little new information, regardless of initial results or timing.

## Contribution

The study reveals that repeat urine cultures within six days rarely yield new diagnostic insights in hospitalized patients.

## Key findings

- Repeat urine cultures within six days provided redundant information regardless of initial culture results.
- Diagnostic yield was low even when adjusting positivity thresholds to 10,000 or 100,000 CFU/mL.

## Abstract

We analyzed the diagnostic yield of repeat urine cultures in a retrospective study of adult inpatients. Most urine cultures repeated at less than 6 days provided redundant information. This was true whether the index culture was positive or negative, and whether the threshold for positivity was 10,000 or 100,000 CFU/mL.