Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts 02215, USA.
Infect Control Hosp Epidemiol. 2012 Feb;33(2):114-21. doi: 10.1086/663714. Epub 2011 Dec 23.
Hospitalized patients are at increased risk for acquisition of methicillin-resistant Staphylococcus aureus (MRSA). As hospital length of stay shortens, hospital-acquired MRSA events may be more likely to be detected after discharge.
We assessed the impact of attributing MRSA cases discovered within 30 days after discharge to the most recent hospitalization and identified patient characteristics associated with MRSA detection after discharge.
Retrospective cohort study.
Twenty-seven acute care hospitals in Orange County, California.
Adult acute care admissions (2002-2007).
Using a countywide hospital data set containing diagnostic codes with present-on-admission (POA) indicators, we identified the first admission with a MRSA code for each patient. This incident MRSA admission was defined as predischarge-detected (pre-DD) hospital-onset MRSA (HO-MRSA) when MRSA was not POA. If MRSA was POA and a prior admission occurred within 30 days, this prior admission was assigned postdischarge-detected (post-DD) HO-MRSA. We evaluated the impact of including post-DD HO-MRSA in the calculation of hospital HO-MRSA incidence using signed-rank tests and reviewed changes in hospital rankings. We conducted multivariate comparisons of patient characteristics of pre-DD versus post-DD HO-MRSA patients.
Among 1,217,253 at-risk hospitalizations, the inclusion of post-DD HO-MRSA tripled the median hospital HO-MRSA incidence, from 12.2 to 35.7 cases per 10,000 at-risk admissions (P < .0001). Hospital ranking changed substantially when including post-DD HO-MRSA. Patients with shorter stays were more likely to have post-DD MRSA.
On the basis of administrative claims data, the inclusion of post-DD HO-MRSA significantly increased the estimated HO-MRSA incidence and altered hospital rankings. This finding underscores the limitations of single-facility data when deriving HO-MRSA incidence and rank.
住院患者感染耐甲氧西林金黄色葡萄球菌（MRSA）的风险增加。随着住院时间的缩短，医院获得性 MRSA 事件可能更有可能在出院后被发现。
我们评估了将出院后 30 天内发现的 MRSA 病例归因于最近一次住院的影响，并确定了与出院后 MRSA 检测相关的患者特征。
回顾性队列研究。
加利福尼亚州奥兰治县的 27 家急性护理医院。
2002-2007 年成人急性护理入院患者。
使用包含入院时诊断代码和现患（POA）指标的全县医院数据集，我们确定了每位患者的第一个 MRSA 代码入院。当 MRSA 不是 POA 时，这种偶发的 MRSA 入院被定义为出院前检测到（预 DD）医院获得性 MRSA（HO-MRSA）。如果 MRSA 是 POA 且在 30 天内发生过先前的入院，则将该先前的入院归因于出院后检测到（后 DD）HO-MRSA。我们使用符号秩检验评估了在计算医院 HO-MRSA 发生率时包含后 DD HO-MRSA 的影响，并审查了医院排名的变化。我们对预 DD 与后 DD HO-MRSA 患者的患者特征进行了多变量比较。
在 1217253 例有风险的住院患者中，包含后 DD HO-MRSA 将医院 HO-MRSA 发生率的中位数增加了两倍，从每 10000 例有风险的入院患者 12.2 例增加到 35.7 例（P <.0001）。包含后 DD HO-MRSA 后，医院排名发生了重大变化。住院时间较短的患者更有可能在后 DD 时发生 MRSA。
基于行政索赔数据，包含后 DD HO-MRSA 显著增加了估计的 HO-MRSA 发生率，并改变了医院排名。这一发现突显了从医院 HO-MRSA 发生率和排名中得出结论时单设施数据的局限性。
