Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethedsa, MD, USA.
Stat Med. 2011 May 10;30(10):1090-104. doi: 10.1002/sim.4187. Epub 2011 Feb 21.
This paper defines absolute risk and some of its properties, and presents applications in breast cancer counseling and prevention. For counseling, estimates of absolute risk give useful perspective and can be used in management decisions that require weighing risks and benefits, such as whether or not to take tamoxifen to prevent breast cancer. Absolute risk models are also useful in designing intervention trials to prevent breast cancer and in assessing the potential reductions in absolute risk of disease that might result from reducing exposures that are associated with breast cancer. In these applications, it is important that the risk model be well calibrated, namely that it accurately predicts the numbers of women who will develop breast cancer in various subsets of the population. Absolute risk models are also needed to implement a 'high risk' prevention strategy that identifies a high-risk subset of the population and focuses intervention efforts on that subset. The limitations of the high-risk strategy are discussed, including the need for risk models with high discriminatory accuracy, and the need for less toxic interventions that can reduce the threshold of risk above which the intervention provides a net benefit. I also discuss the potential use of risk models in allocating prevention resources under cost constraints. High discriminatory accuracy of the risk model, in addition to good calibration, is desirable in this application, and the risk assessment should not be expensive in comparison with the intervention.
本文定义了绝对风险及其一些性质，并介绍了其在乳腺癌咨询和预防中的应用。对于咨询，绝对风险的估计提供了有用的视角，并可用于需要权衡风险和收益的管理决策，例如是否服用他莫昔芬预防乳腺癌。绝对风险模型也可用于设计预防乳腺癌的干预试验，以及评估通过减少与乳腺癌相关的暴露来降低疾病绝对风险的潜在效果。在这些应用中，风险模型必须具有良好的校准能力，即它必须准确预测在人群的不同亚组中发生乳腺癌的女性数量。绝对风险模型还需要实施“高危”预防策略，该策略确定了高危人群的亚组，并将干预重点放在该亚组上。本文还讨论了高危策略的局限性，包括需要具有高区分准确性的风险模型，以及需要降低风险阈值的毒性较小的干预措施，以便在提供净收益的情况下进行干预。我还讨论了风险模型在成本约束下分配预防资源的潜在用途。在这种应用中，风险模型除了良好的校准外，还需要具有较高的区分准确性，并且与干预相比，风险评估不应昂贵。
