While screening mammography has been demonstrated to contribute to reducing mortality due to breast cancer, some have suggested that reduced all-cause mortality should constitute the burden of proof for effectiveness. Using a microsimulation model of the development, detection and treatment of breast cancer it is straightforward to demonstrate that this is an unrealistic expectation for trials of practical size and period of observation, even where the reduction of breast cancer mortality is substantial. Estimates of all-cause mortality will depend not only on the efficacy of the screening intervention, but also on the alignment between the age distribution of the effect of screening on reduction of deaths and that of the other major causes of death. The size of a randomized trial required to demonstrate a reduction in all-cause mortality will, therefore, depend on the length and timing of the observation period and will be typically at least ten times larger than the size of a trial powered to test for a reduction in deaths due to breast cancer. For breast cancer, which represents a small fraction of overall deaths, all-cause mortality is not a practical, nor informative metric for assessing the effectiveness of screening.

中文翻译：

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全因死亡率作为评估乳腺癌筛查的一项指标的价值。

尽管已经证明了乳腺钼靶筛查可以降低乳腺癌的死亡率，但有人认为降低全因死亡率应该构成有效性证据的负担。使用乳腺癌发展，检测和治疗的微观模拟模型，可以直接证明这对实际规模和观察期的试验是不切实际的期望，即使在乳腺癌死亡率降低显着的情况下也是如此。全因死亡率的估算不仅取决于筛查干预的有效性，还取决于筛查对减少死亡影响的年龄分布与其他主要死亡原因之间的一致性。为了证明全因死亡率降低，需要进行一项随机试验，因此，取决于观察期的长短和时机，通常将比试验性试验至少大十倍，该试验旨在测试因乳腺癌导致的死亡减少。对于仅占总死亡人数一小部分的乳腺癌，全因死亡率既不是评估筛查效果的实用方法，也不是提供信息的指标。