A statistical method for determining normal ranges from laboratory data including values below the minimum detectable value.
A statistical method for determining normal ranges from laboratory data including values below the minimum detectable value.
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一种根据实验室数据确定正常范围（包括低于最小可检测值的值）的统计方法。
DOI：
10.1093/clinchem/25.12.2011
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发表时间：
1979
影响因子：
9.3
通讯作者：
L. Heminger
中科院分区：
文献类型：
--
作者：
J. Tsay;I. Chen;H. Maxon;L. Heminger
从含有不可测值的实验室数据中确定正常范围是多肽激素放射免疫分析中经常遇到的问题。在过去，这样的测定通常是基于中间点方法或一端Winsorized方法。还报告了一种使用概率纸的图解方法。我们认为最大似然估计是从这类数据(I类删失数据)中确定正常范围的一种更合适的统计方法。用这种方法，可以估计平均偏差和标准偏差，从而可以估计容差限度。以对数正态分布为基础，用极大似然估计法确定了93名健康受试者血清促甲状腺素值的正常范围。虽然14%的受试者无法检测到血清促甲状腺激素含量，但可以计算出正常范围。以95%可信度95%人群的耐受范围计算出促甲状腺激素的正常范围为0.51-5.75mU/L，平均值为1.71mU/L，并预测91.4%的未检出的血清促甲状腺激素值将落在正常范围内。
Determination of normal ranges from laboratory data containing undectable values is a frequently encountered problem in the radioimmunoassay of peptide hormones. In the past, such determinations usually have been based on the mid-point method or the one-end Winsorized method. A graphic method involving the use of probability paper has also been reported. We propose that the maximum-likelihood estimation is a more appropriate statistical method for the determination of normal range from this type of data (Type I censored data). With this method, the mean and standard deviation, and hence the tolerance limits, can be estimated. We used the maximum-likelihood estimation method to determine the normal range of serum thyrotropin values obtained from 93 healthy subjects, based on a log normal distribution. Although the serum thyrotropin content was undetectable in 14% of the subjects, a normal range could be calculated. Using tolerance limits for 95% coverage of the population with 90% confidence, we calculated the normal range of thyrotropin to be 0.51-5.75 milliunits/L, with a mean value of 1.71 milliunits/L, and predicted that 91.4% of undetectable serum thyrotropin values will fall within the normal range.