All-cause mortality in randomized trials of cancer screening
All-cause mortality in randomized trials of cancer screening
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DOI：
10.1093/jnci/94.3.167
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发表时间：
2002-02-06
影响因子：
10.3
通讯作者：
Welch, HG
中科院分区：
文献类型：
--
作者：
Black, WC;Haggstrom, DA;Welch, HG
背景资料。在随机癌症筛查试验中，最被广泛接受的终点是特定疾病的死亡率。然而，这一终点的有效性取决于可以准确确定死因的假设。另一种终点是全因死亡率，这只取决于对死亡及其发生时间的准确确定。我们在已发表的随机癌症筛查试验中比较了疾病特异性死亡率和全原因死亡率，以间接评估疾病特异性死亡率终点的有效性。方法：我们检查了所有已发表的癌症筛查的随机试验，两个终点都是可用的(7个乳房X光检查，3个粪便潜血检测，2个胸部X光肺癌筛查)。对于每个随机试验，我们从对照组中减去筛查组中观察到的疾病特定死亡率，从控制组中减去筛查组中观察到的全因死亡率。然后，我们比较了这两种死亡率指标的差异。结果：在12个试验中的5个试验中，两种死亡率的差异是相反的，这表明筛查的效果相反。在这五项试验中的四项中，筛查组的疾病特异性死亡率低于对照组，而全因死亡率相同或更高。在剩下的七个试验中，有两个死亡率差异方向相同，但其大小不一致；即，在对照组中，全原因死亡率的差异超过了特定疾病的死亡率。因此，12项试验中有7项的结果在方向或大小上不一致。结论：在随机癌症筛查试验中，疾病特异性和全因死亡终点之间存在主要的不一致。因为全因死亡率不受归类偏差的影响！在解释随机癌症筛查试验的结果时，应该对其进行检查。
Background. The most widely accepted end point in randomized cancer screening trials is disease-specific mortality. The validity of this end point, however, rests on the assumption that cause of death can be determined accurately. An alternative end point is all-cause mortality, which depends only on the accurate ascertainment of deaths and when they occur. We compared disease-specific and all-cause mortality in published randomized cancer-screening trials to indirectly assess the validity of the disease-specific mortality end point. Methods: We examined all 12 published randomized trials of cancer screening for which both end points were, available (seven of mammography, three of fecal occult blood detection, and two of chest x-ray screening for lung cancer). For each randomized trial, we subtracted disease-specific mortality observed in the screened group from that observed in the control group and all-cause mortality in the screened group from that in the control group. We then compared the differences in these two mortality measures. Results: In five of the 12 trials, differences in the two mortality, rates went in opposite directions, suggesting opposite effects of screening. In four of these five trials, disease-specific mortality was lower in the screened group than in the control group, whereas all-cause mortality was the same or higher. In two of the remaining seven trials, the mortality rate differences were in the same direction but their magnitudes were inconsistent; i.e., the difference in all-cause mortality exceeded the disease-specific mortality in the control group. Thus, results of seven of the 12 trials were inconsistent in their direction or magnitude. Conclusion: Major inconsistencies were identified in disease-specific and all-cause mortality end points in randomized cancer screening trials. Because all-cause mortality is not affected by bias in classifying the cause! of death, it should be examined when interpreting the results of randomized cancer-screening trials.