Elting Linda S, Cooksley Catherine, Bekele B Nebiyou, Frumovitz Michael, Avritscher Elenir B C, Sun Charlotte, Bodurka Diane C
Department of Biostatistics and Applied Mathematics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Cancer. 2006 Jun 1;106(11):2452-8. doi: 10.1002/cncr.21907.
The generalizability of clinical trial results is questionable, because fewer than 5% of cancer patients participate. The authors examined the comparability of clinical trial participants and nonparticipants and the potential impact of differences.
A retrospective cohort of 19,340 cancer patients who were diagnosed between January 1990 and December 1997 was characterized by trial participation. The distributions of prognostically important factors among trial participants were compared with the distributions among nonparticipants and the population of patients diagnosed during the same period in the Surveillance, Epidemiology, and End Results population. The impact of these factors on survival was examined by using a Cox proportional hazards analysis.
Trial participants were younger and had better performance status and fewer comorbid conditions compared with nonparticipants. However, participants were more likely to have locally advanced disease, positive lymph node status, poorly differentiated tumors, liver metastases, and multiple metastatic sites. The former factors were associated with significantly longer survival, whereas the later factors were associated with significantly shorter survival.
The lack of comparability between trial participants and nonparticipants called into question the generalizability of clinical trial results. Although selective recruitment for clinical trials is justified, the authors encourage the use of population-based trials of effectiveness in "all comers."
由于参与临床试验的癌症患者不足5%，临床试验结果的可推广性受到质疑。作者研究了临床试验参与者与非参与者的可比性以及差异的潜在影响。
对1990年1月至1997年12月期间诊断的19340例癌症患者进行回顾性队列研究，以试验参与情况为特征。将试验参与者中预后重要因素的分布与非参与者以及同期在监测、流行病学和最终结果人群中诊断的患者人群的分布进行比较。通过Cox比例风险分析研究这些因素对生存的影响。
与非参与者相比，试验参与者更年轻，体能状态更好，合并症更少。然而，参与者更有可能患有局部晚期疾病、淋巴结阳性、肿瘤分化差、肝转移和多个转移部位。前一组因素与显著更长的生存期相关，而后面这些因素与显著更短的生存期相关。
试验参与者与非参与者之间缺乏可比性，这使得临床试验结果的可推广性受到质疑。尽管为临床试验进行选择性招募是合理的，但作者鼓励在“所有患者”中开展基于人群的有效性试验。
