The impact of the use of multiple risk indicators for fracture on case-finding strategies:: a mathematical approach
The impact of the use of multiple risk indicators for fracture on case-finding strategies:: a mathematical approach
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DOI：
10.1007/s00198-004-1689-z
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发表时间：
2005-03-01
影响因子：
4
通讯作者：
Kanis, JA
中科院分区：
文献类型：
--
作者：
De Laet, C;Odén, A;Kanis, JA
骨密度（BMD）测量对骨折概率分层的价值可以通过骨密度测量与独立临床风险指标相结合的病例发现策略来增强。假定的危险指标包括年龄和性别、身体质量指数或体重、既往骨折、皮质类固醇的使用，以及可能的其他因素。本研究的目的是建立一个数学框架，以量化在病例发现中使用风险指标与骨密度组合的影响。骨折概率可以表示为风险梯度，即每骨密度标准差（SD）变化的相对骨折风险（RR）。通过添加其他连续或分类风险指标，可以得到接近正态分布的风险指标的连续分布。这样就有可能计算出个人的风险，并将其与按年龄和性别分层的人群中的平均风险进行比较。骨折风险梯度为2 / SD的风险指标表明，36%的人群的骨折风险高于平均水平。在这样选择的个体中，风险平均是一般人群的1.7倍。其中，通过几个风险指标的组合，测试的风险梯度增加到4 / SD，较小的比例（24%）被确定为高于平均风险，但该组的平均风险是总体的3.1倍，这是一个更好的表现。在较高的风险阈值下，也发现了类似的现象。我们得出的结论是，尽管检测到的高危人群比例的变化很小，但当每SD的RR较高时，测试的性能得到改善，这表明被确定为高危人群的平均风险较高。将临床风险指标与骨密度相结合的病例查找策略提高了效率，同时对需要治疗的个体数量产生了适度影响。因此，提高了成本效益。
The value of bone mineral density (BMD) measurements to stratify fracture probability can be enhanced in a case-finding strategy that combines BMD measurement with independent clinical risk indicators. Putative risk indicators include age and gender, BMI or weight, prior fracture, the use of corticosteroids, and possibly others. The aim of the present study was to develop a mathematical framework to quantify the impact of using combinations of risk indicators with BMD in case finding. Fracture probability can be expressed as a risk gradient, i.e. a relative risk (RR) of fracture per standard deviation (SD) change in BMD. With the addition of other continuous or categorical risk indicators a continuous distribution of risk indicators is obtained that approaches a normal distribution. It is then possible to calculate the risk of individuals compared with the average risk in the population, stratified by age and gender. A risk indicator with a gradient of fracture risk of 2 per SD identified 36% of the population as having a higher than average fracture risk. In individuals so selected, the risk was on average 1.7 times that of the general population. Where, through the combination of several risk indicators, the gradient of risk of the test increased to 4 per SD, a smaller proportion (24%) was identified as having a higher than average risk, but the average risk in this group was 3.1 times that of the population, which is a much better performance. At higher thresholds of risk, similar phenomena were found. We conclude that, whereas the change of the proportion of the population detected to be at high risk is small, the performance of a test is improved when the RR per SD is higher, indicated by the higher average risk in those identified to be at risk. Case-finding strategies that combine clinical risk indicators with BMD have increased efficiency, while having a modest impact on the number of individuals requiring treatment. Therefore, the cost-effectiveness is enhanced.