Center for Surgical Trials and Evidence-Based Practice (C-STEP), Department of Surgery, University of Texas Health Science Center at Houston, Houston, TX 77026, USA.
J Am Coll Surg. 2011 Aug;213(2):231-5. doi: 10.1016/j.jamcollsurg.2011.04.004. Epub 2011 May 31.
Although rates of superficial surgical site infection (SSI) are increasingly used as measures of hospital quality, the statistical reliability of using SSI rates in this context is uncertain. We used the American College of Surgeons National Surgical Quality Improvement Program data to determine the reliability of SSI rates as a measure of hospital performance and to evaluate the effect of hospital caseload on reliability.
We examined all patients who underwent colon resection in hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program in 2007 (n = 18,455 patients, n = 181 hospitals). We first calculated the number of cases and the risk-adjusted rate of SSI at each hospital. We then used hierarchical modeling to estimate the reliability of this quality measure for each hospital. Finally, we quantified the proportion of hospital-level variation in SSI rates due to patient characteristics and measurement noise.
The average number of colon resections per hospital was 102 (SD 65). The risk-adjusted rate of superficial SSI was 10.5%, but varied from 0 to 30% across hospitals. Approximately 35% of the variation in SSI rates was explained by noise, 7% could be attributed to patient characteristics, and the remaining 58% represented true differences in SSI rates. Just more than half of the hospitals (54%) had a reliability >0.70, which is considered a minimum acceptable level. To achieve this level of reliability, 94 cases were required.
SSI rates are a reliable measure of hospital quality when an adequate number of cases have been reported. For hospitals with inadequate caseloads, the National Surgical Quality Improvement Program sampling strategy could be altered to provide enough cases to ensure reliability.
尽管浅表手术部位感染（SSI）的发生率越来越多地被用作医院质量的衡量标准，但在这种情况下使用 SSI 发生率的统计可靠性尚不确定。我们使用美国外科医师学会国家外科质量改进计划的数据来确定 SSI 发生率作为衡量医院绩效的可靠性，并评估医院病例量对可靠性的影响。
我们检查了 2007 年参加美国外科医师学会国家外科质量改进计划的医院中接受结肠切除术的所有患者（n = 18455 例，n = 181 家医院）。我们首先计算了每家医院的病例数和调整风险后的 SSI 发生率。然后，我们使用层次模型估计了这种质量测量对每家医院的可靠性。最后，我们量化了由于患者特征和测量噪声导致的 SSI 发生率的医院间差异的比例。
每家医院平均进行 102 例（SD 65）结肠切除术。浅表 SSI 的调整风险率为 10.5%，但医院之间的差异从 0 到 30%不等。SSI 发生率的变化约有 35%归因于噪声，7%可归因于患者特征，其余 58%代表 SSI 发生率的真实差异。超过一半的医院（54%）具有 >0.70 的可靠性，这被认为是一个可接受的最低水平。要达到这个可靠性水平，需要 94 例。
当报告了足够数量的病例时，SSI 发生率是衡量医院质量的可靠指标。对于病例量不足的医院，可以改变美国外科医师学会国家外科质量改进计划的抽样策略，以提供足够的病例来确保可靠性。
