Hodgson David C, Zhang Wei, Zaslavsky Alan M, Fuchs Charles S, Wright William E, Ayanian John Z
Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario, Canada.
J Natl Cancer Inst. 2003 May 21;95(10):708-16. doi: 10.1093/jnci/95.10.708.
Postoperative mortality after some types of cancer surgery is inversely related to the number of operations performed at a hospital (i.e., hospital volume). This study assessed the association of hospital volume with colostomy rates and survival for patients with rectal cancer in a large representative cohort identified from the California Cancer Registry.
We identified 7257 patients diagnosed from January 1, 1994, through December 31, 1997, with stage I-III rectal cancer who underwent surgical resection. Registry data were linked to hospital discharge abstracts and ZIP-code-level data from the 1990 U.S. Census. Associations of hospital volume with permanent colostomy and 30-day mortality were assessed with the Mantel-Haenszel trend test and logistic regression. Overall survival was examined with the Kaplan-Meier method and a multivariable Cox proportional hazards model. Multivariable analyses adjusted for demographic and clinical variables and patient clustering within hospitals. All tests of statistical significance were two-sided.
In unadjusted analyses across decreasing quartiles of hospital volume, we observed statistically significant increases in colostomy rates (29.5%, 31.8%, 35.2%, and 36.6%; P<.001) and in 30-day postoperative mortality (1.6%, 1.6%, 2.9%, and 4.8%; P<.001) and a decrease in 2-year survival (83.7%, 83.2%, 80.9%, and 76.6%; P<.001). The adjusted risks of permanent colostomy (odds ratio [OR] = 1.37, 95% confidence interval [CI] = 1.10 to 1.70), 30-day mortality (OR = 2.64, 95% CI = 1.41 to 4.93), and 2-year mortality (hazard ratio = 1.28, 95% CI = 1.15 to 1.44) were greater for patients at hospitals in the lowest volume quartile than for patients at hospitals in the highest volume quartile. Stratification by tumor stage and comorbidity index did not appreciably affect the results. Adjusted colostomy rates varied statistically significantly (P<.001) among individual hospitals independent of volume.
Rectal cancer patients who underwent surgery at high-volume hospitals were less likely to have a permanent colostomy and had better survival rates than those treated in low-volume hospitals. Identifying processes of care that contribute to these differences may improve patients' outcomes in all hospitals.
某些类型的癌症手术后的术后死亡率与医院进行的手术数量（即医院规模）呈负相关。本研究在从加利福尼亚癌症登记处确定的一个大型代表性队列中，评估了医院规模与直肠癌患者结肠造口率及生存率之间的关联。
我们确定了1994年1月1日至1997年12月31日期间诊断为I - III期直肠癌并接受手术切除的7257例患者。登记处数据与医院出院摘要以及1990年美国人口普查的邮政编码级数据相关联。采用Mantel - Haenszel趋势检验和逻辑回归评估医院规模与永久性结肠造口术及30天死亡率之间的关联。采用Kaplan - Meier方法和多变量Cox比例风险模型检查总生存率。多变量分析对人口统计学和临床变量以及医院内患者聚类进行了调整。所有统计学显著性检验均为双侧检验。
在按医院规模降序排列的四分位数进行的未调整分析中，我们观察到结肠造口率（分别为29.5%、31.8%、35.2%和36.6%；P <.001）、术后30天死亡率（分别为1.6%、1.6%、2.9%和4.8%；P <.001）有统计学显著增加，以及2年生存率（分别为83.7%、83.2%、80.9%和76.6%；P <.001）有下降。与规模最高四分位数医院的患者相比，规模最低四分位数医院的患者永久性结肠造口术的调整风险（比值比[OR] = 1.37，95%置信区间[CI] = 1.10至1.70）、30天死亡率（OR = 2.64，95% CI = 1.41至4.93）和2年死亡率（风险比 = 1.28，95% CI = 1.15至1.44）更高。按肿瘤分期和合并症指数分层并未明显影响结果。独立于规模的各医院之间调整后的结肠造口率在统计学上有显著差异（P <.001）。
在大规模医院接受手术的直肠癌患者比在小规模医院接受治疗的患者进行永久性结肠造口术的可能性更小，且生存率更高。确定导致这些差异的护理过程可能会改善所有医院患者的治疗结果。
