Cram Peter, Lu Xin, Kates Stephen L, Li Yue, Miller Benjamin J
Department of Internal Medicine, Division of General Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA ; CADRE, Iowa City Veterans Administration Medical Center, Iowa City, IA, USA.
Geriatr Orthop Surg Rehabil. 2011 Jul;2(4):135-47. doi: 10.1177/2151458511419847.
Little is known about readmission rates for total hip and total knee arthroplasty (THA and TKA). Our objective was to examine readmission rates and whether hospitals with high and low readmission rates at baseline remain outliers in subsequent years.
We identified Medicare beneficiaries who underwent THA (N = 245 995) and TKA (N = 517 867) between 2003 and 2005. We created four different hospital cohorts: low and high volume for THA and TKA. We calculated 30-day risk-standardized readmission rates (RSRRs) for each hospital for each year. Hospitals were defined as having low (lowest 25% of all hospitals), high (highest 25% of hospitals), and intermediate readmission rates (all others) for each year. Hospitals were labeled outliers if they had consistently low or high readmission rates for all years. We examined the number and characteristics of outlier and nonoutlier hospitals.
Unadjusted readmission rates in 2003 for THA ranged from 0% to 94.7% (inter-quartile range: 0%-7.0%) and for TKA from 0% to 94.4% (inter-quartile range: 0.7%-5.9%). Of 255 low-volume THA hospitals with low readmission rates in 2003 (RSRRs ≤3.5%), 34 were outliers for all 3 years-significantly more than predicted (P < .0001). Likewise, of 256 low-volume THA hospitals with high readmission rates (RSRRs ≥5.8%) in 2003, 33 were outliers for all 3 years (P < .0001). Outlier and nonoutlier hospitals did not differ in meaningful ways (teaching status and staffing ratios). Results were similar for other hospital cohorts.
Using a 3-year window allows for identification of hospitals with consistently higher and lower readmission rates than predicted.
关于全髋关节置换术和全膝关节置换术（THA和TKA）的再入院率，人们了解甚少。我们的目标是研究再入院率，以及在基线时再入院率高和低的医院在随后几年是否仍然是异常值。
我们确定了2003年至2005年间接受THA（N = 245995）和TKA（N = 517867）的医疗保险受益人。我们创建了四个不同的医院队列：THA和TKA的低容量和高容量队列。我们计算了每家医院每年的30天风险标准化再入院率（RSRR）。每年，医院被定义为具有低（所有医院中最低的25%）、高（所有医院中最高的25%）和中等再入院率（其他所有医院）。如果医院在所有年份的再入院率一直很低或很高，则被标记为异常值。我们检查了异常值和非异常值医院的数量和特征。
2003年THA的未调整再入院率范围为0%至94.7%（四分位间距：0%至7.0%），TKA为0%至94.4%（四分位间距：0.7%至5.9%）。在2003年再入院率低（RSRR≤3.5%）的255家低容量THA医院中，有34家在所有3年都是异常值——显著多于预期（P <.0001）。同样，在2003年再入院率高（RSRR≥5.8%）的256家低容量THA医院中，有33家在所有3年都是异常值（P <.0001）。异常值和非异常值医院在有意义的方面（教学状态和人员配备比例）没有差异。其他医院队列的结果相似。
使用3年的时间窗口可以识别出再入院率一直高于或低于预期的医院。
