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.

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.

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