Patient-month modeling for longitudinal blood culture contamination surveillance during a major healthcare-system disruption: a single-center interrupted time-series study

IF 1.7 4区医学 Q3 INFECTIOUS DISEASES

Journal of Infection and Chemotherapy Pub Date : 2026-11-01 Epub Date: 2026-10-20 DOI:10.1016/j.jiac.2026.103107

Kohei Hasegawa, Junji Kumasawa, Kaya Aonuma

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引用次数: 0

Abstract

Introduction

Blood culture contamination (BCC) is an important diagnostic quality indicator, but crude temporal comparisons may be misleading when repeated sampling within patients is not considered. We evaluated longitudinal changes in BCC rates before, during, and after the COVID-19 pandemic using patient-month Poisson generalized estimating equations (GEE).

Methods

This single-center retrospective study included blood culture sets obtained at a tertiary hospital in Japan from April 2017 to June 2025. Eligible episodes had at least two sets drawn within 24 h. Interrupted time-series analysis estimated incidence rate ratios (IRRs) for level and slope changes at pandemic and post-reclassification transitions, with the number of sets as an offset and adjustment for seasonality and within-patient correlation.

Results

Among 85,955 blood culture sets, 84,213 sets from 41,732 episodes in 23,705 patients were analyzed. Crude BCC rates were 1.05%, 1.55%, and 1.49% in the prepandemic, pandemic, and post-reclassification periods. No significant overall level or slope changes were observed: prepandemic-to-pandemic level-change IRR, 1.23 (95% CI, 0.93–1.62); slope-change IRR, 1.00 (95% CI, 0.99–1.01); pandemic-to-post-reclassification level-change IRR, 0.88 (95% CI, 0.68–1.14); and slope-change IRR, 0.99 (95% CI, 0.98–1.01). Exploratory subgroup analyses suggested setting-specific post-reclassification changes in the intensive care unit. Sensitivity analyses were generally consistent, although the Omicron-era breakpoint analysis suggested sensitivity to breakpoint specification.

Conclusion

Patient-month Poisson GEE-based analysis showed that crude increases in BCC rates were not accompanied by statistically significant overall level or slope changes after accounting for repeated patient-level sampling and seasonality. Crude BCC trends should therefore be interpreted cautiously in longitudinal microbiology surveillance.

查看原文本刊更多论文

主要医疗保健系统中断期间纵向血培养污染监测的患者月模型：单中心中断时间序列研究。

简介：血培养污染（BCC）是一项重要的诊断质量指标，但如果不考虑患者体内重复采样，粗略的时间比较可能会产生误导。我们使用患者-月泊松广义估计方程（GEE）评估了COVID-19大流行之前、期间和之后BCC率的纵向变化。方法：这项单中心回顾性研究纳入了2017年4月至2025年6月在日本一家三级医院获得的血培养试剂盒。符合条件的剧集在24小时内至少有两组抽签 h。中断时间序列分析估计了大流行和重新分类后过渡期间水平和斜率变化的发病率比（IRRs），并将组数作为季节性和患者内部相关性的抵消和调整。结果：在85,955套血培养试剂盒中，分析了23,705例患者41,732次的84,213套血培养试剂盒。在大流行前、大流行和重新分类后时期，粗BCC率分别为1.05%、1.55%和1.49%。未观察到显著的总体水平或斜率变化：大流行前至大流行水平变化的IRR为1.23 (95% CI, 0.93-1.62)；斜率变化IRR为1.00 (95% CI, 0.99-1.01)；大流行至重新分类后的水平变化IRR， 0.88 (95% CI, 0.68-1.14)；斜率变化IRR为0.99 （95% CI, 0.98-1.01）。探索性亚组分析表明重症监护室的重新分类后发生了特定环境的变化。敏感性分析通常是一致的，尽管ommicron时代的断点分析表明对断点规范的敏感性。结论：基于患者月泊松基因的分析显示，在考虑了重复的患者水平采样和季节性因素后，粗粗的BCC率增加并不伴随着统计学上显著的总体水平或斜率变化。因此，在纵向微生物学监测中应谨慎解释粗BCC趋势。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Infection and Chemotherapy INFECTIOUS DISEASES-PHARMACOLOGY & PHARMACY

CiteScore

4.10

自引率

4.50%

发文量

303

审稿时长

47 days

期刊介绍： The Journal of Infection and Chemotherapy (JIC) — official journal of the Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases — welcomes original papers, laboratory or clinical, as well as case reports, notes, committee reports, surveillance and guidelines from all parts of the world on all aspects of chemotherapy, covering the pathogenesis, diagnosis, treatment, and control of infection, including treatment with anticancer drugs. Experimental studies on animal models and pharmacokinetics, and reports on epidemiology and clinical trials are particularly welcome.