Fiorentino Dary D
a Southern California Research Institute , Van Nuys , California.
Traffic Inj Prev. 2018 May 19;19(4):352-357. doi: 10.1080/15389588.2018.1423561. Epub 2018 Mar 20.
Two of the 3 standardized field sobriety tests that U.S. law enforcement uses at roadside checks have a postural equilibrium component to them. Those tests have been validated to detect impairment caused by blood alcohol concentrations (BACs) of 0.08 g/dL or above. Many medical and traffic safety associations support a lower limit, and one state, Utah, has passed a law to lower the limit to 0.05 g/dL. Many studies have examined the effects of alcohol on postural control (of which postural equilibrium is a component), with a consensus emerging that impairment is usually found at BACs greater than 0.06 g/dL. Most of these studies, however, had a relatively small number of subjects, usually between 10 and 30. The current study collected data from a much larger sample.
The objective of this study was to provide additional evidence that posture control is negatively affected at BACs greater than 0.06 g/dL or breath alcohol concentrations (BrACs) of 0.06 g/210 L.
This was a between-subjects study, with BrAC group as the independent variable (5 levels: 0.00, 0.04, 0.06, 0.08, and 0.10 g/210 L); 4 measures of postural control as the dependent variables; and age, height, and weight as the covariates. Posture control was measured with a force-sensing platform connected to a computer. The feet's center of pressure (CoP) on the platform was recorded and the corresponding movement of the body in the anterior-posterior and lateral planes was derived. Participants (N = 96) were randomly assigned to one of the BrAC groups. Positive BrAC groups were compared to the zero BrAC group. Data were examined with hierarchical multiple regression.
Adjusted for age, height, and weight, the main effect of lateral CoP with eyes open was not statistically significant. There was a statistically significant main effect of alcohol on anterior-posterior CoP excursion with eyes open and with eyes closed and lateral CoP excursion with eyes closed. For all 3 of those variables, only BrACs of 0.08 and 0.10 g/210 L produced differences against zero BrAC. Although the main effect of alcohol on Lateral CoP Excursion with eyes open was not statistically significant, the contrasts between 0 and 0.08 and 0 and 0.10 g/210L BrAC were in the hypothesized direction.
The current study did not directly address the issue of whether the sobriety tests are sensitive to BrACs of 0.05 g/210 L or above; rather, it provides additional evidence that postural control, one of the components of those tests, is relatively unaffected by BrACs lower than 0.08 g/210 L. Additional research is needed on the diagnostic characteristics of the sobriety tests at BrACs lower than 0.08 g/210 L.
美国执法部门在路边检查时使用的3项标准化现场清醒度测试中有两项包含姿势平衡部分。这些测试已被验证可检测出血液酒精浓度（BAC）达到或超过0.08 g/dL所导致的机能受损情况。许多医学和交通安全协会支持更低的限制，并且有一个州，犹他州，已经通过一项法律将限制降低到0.05 g/dL。许多研究已经考察了酒精对姿势控制（姿势平衡是其中一个组成部分）的影响，逐渐形成的共识是通常在BAC大于0.06 g/dL时会出现机能受损。然而，这些研究大多数的受试者数量相对较少，通常在10到30人之间。当前的研究从一个大得多的样本中收集了数据。
本研究的目的是提供更多证据，证明在BAC大于0.06 g/dL或呼气酒精浓度（BrAC）达到0.06 g/210 L时，姿势控制会受到负面影响。
这是一项组间研究，以BrAC组作为自变量（5个水平：0.00、0.04、0.06、0.08和0.10 g/210 L）；4项姿势控制测量指标作为因变量；以及年龄、身高和体重作为协变量。使用连接到计算机的力敏平台测量姿势控制。记录平台上双脚的压力中心（CoP），并得出身体在前后平面和横向平面的相应移动。参与者（N = 96）被随机分配到其中一个BrAC组。将阳性BrAC组与零BrAC组进行比较。使用分层多元回归对数据进行检验。
在对年龄、身高和体重进行校正后，睁眼时横向CoP的主效应无统计学意义。酒精对睁眼和闭眼时前后CoP偏移以及闭眼时横向CoP偏移有统计学意义的主效应。对于所有这3个变量，只有0.08和0.10 g/210 L的BrAC与零BrAC产生差异。尽管酒精对睁眼时横向CoP偏移的主效应无统计学意义，但0与0.08以及0与0.10 g/210 L BrAC之间的对比符合假设方向。
当前的研究没有直接解决清醒度测试对0.05 g/210 L或更高的BrAC是否敏感的问题；相反，它提供了更多证据，证明姿势控制作为这些测试的组成部分之一，相对不受低于0.08 g/210 L的BrAC影响。需要对低于0.08 g/210 L的BrAC时清醒度测试的诊断特征进行更多研究。
