Pounder D J, Kuroda N
Department of Forensic Medicine, University of Dundee, Scotland.
Forensic Sci Int. 1994 Mar 25;65(2):73-80. doi: 10.1016/0379-0738(94)90262-3.
Vitreous humour alcohol concentration (VHAC) and blood alcohol concentration (BAC) measured by gas chromatography were available from 345 medico-legal autopsies. Simple linear regression with BAC as outcome variable and VHAC as predictor variable (range 1-705 mg%) gave the regression equation BAC = 3.03 + 0.852 VHAC with 95% prediction interval +/- 0.019 square root of [7157272 + (VHAC - 189.7)2] and 99% prediction interval +/- 0.025 square root of [7157272 + (VHAC - 189.7)2]. The residual standard deviation of VHAC was 26 mg%, the standard error of the slope 0.0098 and the 95% confidence interval for the slope 0.833-0.871. In practice a BAC of 80 mg% is predicted with 95% certainty by a VHAC of 150 mg% and similarly a BAC of 150 mg% by a VHAC of 232 mg%. The prediction interval is too wide to be of real practical use. Previous authors have provided various formulae, including a simple conversion factor, to predict BAC from VHAC without taking into account the uncertainty of the prediction for an individual subject. A re-analysis of the raw data from previous publications gave in most instances regression equations significantly different from the authors' own.
通过气相色谱法测定了345例法医尸检的玻璃体液酒精浓度（VHAC）和血液酒精浓度（BAC）。以BAC作为结果变量、VHAC作为预测变量（范围为1 - 705mg%）进行简单线性回归，得到回归方程BAC = 3.03 + 0.852VHAC，其95%预测区间为±0.019√[7157272 + (VHAC - 189.7)²]，99%预测区间为±0.025√[7157272 + (VHAC - 189.7)²]。VHAC的残差标准差为26mg%，斜率的标准误差为0.0098，斜率的95%置信区间为0.833 - 0.871。实际上，当VHAC为150mg%时，有95%的把握预测BAC为80mg%；同样，当VHAC为232mg%时，预测BAC为150mg%。预测区间过宽，实际应用价值不大。此前的作者提供了各种公式，包括一个简单的转换因子，用于从VHAC预测BAC，但未考虑个体预测的不确定性。对先前出版物的原始数据进行重新分析，在大多数情况下得到的回归方程与作者自己的有显著差异。
