Department of Medicine, Division of Infectious Diseases, Duke University Medical Center, Durham, North Carolina.
Infect Control Hosp Epidemiol. 2013 Oct;34(10):1055-61. doi: 10.1086/673144. Epub 2013 Aug 29.
Change from nonmolecular to molecular testing techniques is thought to contribute to the increasing trend in incidence of Clostridium difficile infection (CDI); however the degree of effect attributed to this versus other time-related epidemiologic factors is unclear.
We compared the relative change in incidence rate (IRR) of healthcare facility-associated (HCFA) CDI among hospitals in the Duke Infection Control Outreach Network before and after the date of switch from nonmolecular tests to polymerase chain reaction (PCR) using prospectively collected surveillance data from July 2009 to December 2011. Data from 10 hospitals that switched and 22 control hospitals were included. Individual hospital estimates were determined using Poisson regression. We used an interrupted time series approach to develop a Poisson mixed-effects model. Additional regression adjustments were made for clustering and proportion of intensive care unit patient-days. The variable for PCR was treated as a fixed effect; other modeled variables were random effects.
For those hospitals that switched to PCR, mean incidence rate of HCFA CDI before the switch was 6.0 CDIs per 10,000 patient-days compared with 9.6 CDIs per 10,000 patient-days after the switch. Estimates of hospital-specific IRR that compared after the switch with before the switch ranged from 0.89 (95% confidence interval [CI], 0.32-2.44) to 6.91 (95% CI, 1.12-42.54). After adjustment in the mixed-effects model, the overall IRR comparing CDI incidence after the switch to before the switch was 1.56 (95% CI, 1.28-1.90). Time-trend variables did not reach statistical significance.
Hospitals that switched from nonmolecular to molecular tests experienced an approximate 56% increase in the rate of HCFA CDI after testing change.
非分子检测技术向分子检测技术的转变被认为是导致艰难梭菌感染（CDI）发病率上升的原因之一；然而，这种转变对发病率的影响程度与其他与时间相关的流行病学因素的影响程度尚不清楚。
我们比较了杜克感染控制外展网络（Duke Infection Control Outreach Network）中使用前瞻性收集的 2009 年 7 月至 2011 年 12 月的监测数据，在医院从非分子检测转换为聚合酶链反应（PCR）之前和之后，与医疗机构相关（HCFA）CDI 的发病率相对变化率（IRR）。纳入了 10 家转换医院和 22 家对照医院的数据。使用泊松回归确定医院的个体估计值。我们使用中断时间序列方法开发泊松混合效应模型。对聚类和重症监护病房患者天数的比例进行了额外的回归调整。PCR 变量被视为固定效应；其他模型变量是随机效应。
对于那些转换为 PCR 的医院，转换前的 HCFA CDI 平均发病率为每 10000 个患者日 6.0 CDI，转换后的发病率为每 10000 个患者日 9.6 CDI。比较转换后和转换前的医院特异性 IRR 估计值范围为 0.89（95%置信区间[CI]，0.32-2.44）至 6.91（95% CI，1.12-42.54）。在混合效应模型中进行调整后，比较转换后与转换前 CDI 发病率的总体 IRR 为 1.56（95% CI，1.28-1.90）。时间趋势变量未达到统计学意义。
从非分子检测转为分子检测的医院在检测方法改变后，HCFA CDI 的发病率增加了约 56%。
