Washington University School of Medicine, St Louis, Missouri, USA.
Infect Control Hosp Epidemiol. 2010 Mar;31(3):262-8. doi: 10.1086/650447.
To compare incidence of hospital-onset Clostridium difficile infection (CDI) measured by the use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) discharge diagnosis codes with rates measured by the use of electronically available C. difficile toxin assay results.
Cases of hospital-onset CDI were identified at 5 US hospitals during the period from July 2000 through June 2006 with the use of 2 surveillance definitions: positive toxin assay results (gold standard) and secondary ICD-9-CM discharge diagnosis codes for CDI. The chi(2) test was used to compare incidence, linear regression models were used to analyze trends, and the test of equality was used to compare slopes.
Of 8,670 cases of hospital-onset CDI, 38% were identified by the use of both toxin assay results and the ICD-9-CM code, 16% by the use of toxin assay results alone, and 45% by the use of the ICD-9-CM code alone. Nearly half (47%) of cases of CDI identified by the use of a secondary diagnosis code alone were community-onset CDI according to the results of the toxin assay. The rate of hospital-onset CDI found by use of ICD-9-CM codes was significantly higher than the rate found by use of toxin assay results overall (P < .001), as well as individually at 3 of the 5 hospitals (P < .001 for all). The agreement between toxin assay results and the presence of a secondary ICD-9-CM diagnosis code for CDI was moderate, with an overall kappa value of 0.509 and hospital-specific kappa values of 0.489-0.570. Overall, the annual increase in CDI incidence was significantly greater for rates determined by the use of ICD-9-CM codes than for rates determined by the use of toxin assay results (P = .006).
Although the ICD-9-CM code for CDI seems to be adequate for measuring the overall CDI burden, use of the ICD-9-CM discharge diagnosis code for CDI, without present-on-admission code assignment, is not an acceptable surrogate for surveillance for hospital-onset CDI.
通过使用国际疾病分类，第九修订版，临床修正（ICD-9-CM）出院诊断代码来比较医院获得性艰难梭菌感染（CDI）的发生率，与使用电子可得的艰难梭菌毒素检测结果进行比较。
在 2000 年 7 月至 2006 年 6 月期间，在美国的 5 家医院使用 2 种监测定义来确定医院获得性 CDI 病例：阳性毒素检测结果（金标准）和 CDI 的 ICD-9-CM 出院诊断代码。使用卡方检验比较发生率，使用线性回归模型分析趋势，并使用检验来比较斜率。
在 8670 例医院获得性 CDI 中，38%的病例同时使用毒素检测结果和 ICD-9-CM 代码确定，16%的病例仅使用毒素检测结果确定，45%的病例仅使用 ICD-9-CM 代码确定。单独使用次要诊断代码确定的近一半（47%）CDI 病例根据毒素检测结果为社区获得性 CDI。使用 ICD-9-CM 代码确定的医院获得性 CDI 发生率明显高于使用毒素检测结果的发生率（均 P<0.001），在 5 家医院中的 3 家医院也是如此（所有 P<0.001）。毒素检测结果与 CDI 的 ICD-9-CM 诊断代码之间的一致性为中度，总体kappa 值为 0.509，各医院kappa 值为 0.489-0.570。总体而言，使用 ICD-9-CM 代码确定的 CDI 发病率的年增长率明显高于使用毒素检测结果确定的 CDI 发病率（P=0.006）。
尽管 CDI 的 ICD-9-CM 代码似乎足以衡量 CDI 的总体负担，但在没有入院时代码分配的情况下，使用 ICD-9-CM 出院诊断代码不是医院获得性 CDI 监测的可接受替代方法。
