Anderson Kane L, Koval Kenneth J, Spratt Kevin F
Department of Orthopaedics, Dartmouth Medical School, Lebanon, New Hampshire, USA.
Am J Orthop (Belle Mead NJ). 2009 Dec;38(12):606-11.
We assessed the differential complications and mortality rates of teaching versus nonteaching hospitals in July against other month-to-month differences in a cohort of 324,988 elderly patients hospitalized for a femoral neck or intertrochanteric fracture (data taken from the 1998-2003 National Inpatient Sample). Demographics were similar between teaching and nonteaching hospitals and across admission months. The overall mortality rate was 3.64% and was slightly higher in teaching hospitals compared with nonteaching hospitals (3.69% vs. 3.61%, relative risk [RR] = 1.0062, 95% CI 0.99-1.02). The adjusted relative risk (RR) for mortality in July/August was significantly higher than the overall adjusted RR and compared with all other month pairs, indicating higher in-hospital mortality rates in teaching hospitals compared with nonteaching hospitals. Intraoperative complications and length of stay were statistically significantly greater in teaching hospitals but did not demonstrate a "July effect." Teaching hospitals had lower perioperative complication rates. Elderly hip fracture patients treated at teaching hospitals had 12% greater relative risk of mortality in July/August (ie, experience a "July effect") compared with nonteaching hospitals during that time period (1998-2003). Although various methods exist for exploring the "July effect," it is critical to take into account inherent month-to-month variation in outcomes and to use nonteaching hospitals as a control group.
我们评估了教学医院与非教学医院在7月的差异并发症和死亡率，以及在一组324,988名因股骨颈或转子间骨折住院的老年患者中，7月与其他月份之间的差异（数据取自1998 - 2003年国家住院患者样本）。教学医院与非教学医院之间以及各入院月份的人口统计学特征相似。总体死亡率为3.64%，教学医院略高于非教学医院（3.69%对3.61%，相对风险[RR]=1.0062，95%可信区间0.99 - 1.02）。7月/8月死亡率的调整后相对风险（RR）显著高于总体调整后RR，与所有其他月份对相比，表明教学医院的院内死亡率高于非教学医院。教学医院的术中并发症和住院时间在统计学上显著更长，但未显示出“7月效应”。教学医院的围手术期并发症发生率较低。与非教学医院相比，教学医院治疗的老年髋部骨折患者在7月/8月的死亡相对风险高12%（即经历“7月效应”）（1998 - 2003年期间）。尽管存在各种探索 “7月效应” 的方法，但考虑到结果固有的逐月变化并将非教学医院作为对照组至关重要。
