Division of Infectious Diseases, Duke University Medical Center, Durham, North Carolina, USA.
Duke Center for Antimicrobial Stewardship and Infection Prevention, Duke University Medical Center, Durham, North Carolina.
Clin Infect Dis. 2023 Oct 5;77(7):1043-1049. doi: 10.1093/cid/ciad334.
Two-step testing for Clostridioides difficile infection (CDI) aims to improve diagnostic specificity but may also influence reported epidemiology and patterns of treatment. Some providers fear that 2-step testing may result in adverse outcomes if C. difficile is underdiagnosed.
Our primary objective was to assess the impact of 2-step testing on reported incidence of hospital-onset CDI (HO-CDI). As secondary objectives, we assessed the impact of 2-step testing on C. difficile-specific antibiotic use and colectomy rates as proxies for harm from underdiagnosis or delayed treatment. This longitudinal cohort study included 2 657 324 patient-days across 8 regional hospitals from July 2017 through March 2022. Impact of 2-step testing was assessed by time series analysis with generalized estimating equation regression models.
Two-step testing was associated with a level decrease in HO-CDI incidence (incidence rate ratio, 0.53 [95% confidence interval {CI}, .48-.60]; P < .001), a similar level decrease in utilization rates for oral vancomycin and fidaxomicin (utilization rate ratio, 0.63 [95% CI, .58-.70]; P < .001), and no significant level (rate ratio, 1.16 [95% CI, .93-1.43]; P = .18) or trend (rate ratio, 0.85 [95% CI, .52-1.39]; P = .51) change in emergent colectomy rates.
Two-step testing is associated with decreased reported incidence of HO-CDI, likely by improving diagnostic specificity. The parallel decrease in C. difficile-specific antibiotic use offers indirect reassurance against underdiagnosis of C. difficile infections still requiring treatment by clinician assessment. Similarly, the absence of any significant change in colectomy rates offers indirect reassurance against any rise in fulminant C. difficile requiring surgical management.
两步检测法旨在提高艰难梭菌感染（CDI）的诊断特异性，但也可能影响报告的流行病学和治疗模式。一些提供者担心，如果艰难梭菌诊断不足，两步检测可能会导致不良后果。
我们的主要目的是评估两步检测法对报告的医院获得性 CDI（HO-CDI）发病率的影响。作为次要目标，我们评估了两步检测法对艰难梭菌特异性抗生素使用和结肠切除术率的影响，这些指标可以作为诊断不足或治疗延迟的危害的替代指标。这项纵向队列研究包括 2017 年 7 月至 2022 年 3 月期间 8 家地区医院的 2657324 个患者日。通过广义估计方程回归模型的时间序列分析评估两步检测法的影响。
两步检测法与 HO-CDI 发病率的水平下降相关（发病率比，0.53[95%置信区间{CI}，0.48-0.60]；P<0.001），口服万古霉素和非达霉素的使用率也呈类似水平下降（使用率比，0.63[95% CI，0.58-0.70]；P<0.001），但紧急结肠切除术率的水平（比率，1.16[95% CI，0.93-1.43]；P=0.18）或趋势（比率，0.85[95% CI，0.52-1.39]；P=0.51）没有显著变化。
两步检测法与报告的 HO-CDI 发病率下降相关，可能是通过提高诊断特异性实现的。艰难梭菌特异性抗生素使用的平行下降提供了间接保证，表明仍需要通过临床医生评估来治疗需要治疗的艰难梭菌感染。同样，结肠切除术率没有显著变化也提供了间接保证，表明没有任何暴发性艰难梭菌需要手术治疗的增加。
