Why the Workplace Impairment Test (WIT) is Based Upon the 'DRE' Exam

Impairment is defined as 'the state of being diminished, weakened or damaged especially mentally or physically'1, or by being 'in an imperfect or weakened state or condition'2. There is also legal case law3 which defines impairment as any degree of impairment ranging from slight to great and does not need to exhibit a marked departure from normal behaviour.

Safety sensitive positions, such as transportation, aviation, oil and gas, mining, and highly regulated activities such as driving are often examples that are used when discussing concerns pertaining to impairment in the workplace.

However, there are other types of work environments that can be considered safety-sensitive. These include positions such as health care, compounding of medications, arranging loads of shipping materials, and crossing guards responsible for children getting to school safely.

Employees are the foundation of all companies. Ensuring all workplaces have the opportunity to be educated regarding medication safety, as well as alcohol and drug consumption and the effects of this consumption are essential. It is incumbent upon the employer to ensure a safe workplace for everyone.

Validity of DRE Testing

The International Association of Chiefs of Police (IACP) with support from the National Highway Traffic Safety Administration (NHTSA) developed the Drug Recognition Expert (DRE) program in the early 1970s. The training relies heavily upon the Standardized Field Sobriety Tests (SFSTs).
These psychophysical tests are the methods of investigating the mental and physical characteristics of a person suspected of alcohol or drug impairment. Most psychophysical tests employ the concept of divided attention to assess a suspect’s impairment.

Standardized Field Sobriety Testing is composed of three tests, Horizontal Gaze Nystagmus (HGN), Walk and Turn (WAT) and One Leg Stand (OLS). Developed from a series of controlled laboratory environments and assessed with field studies, scientifically validated clues of alcohol impairment have been identified for each of these three tests.

The validity and sensitivity of these tests have been demonstrated in three commonly referred studies, which include:
The Colorado Study
To be genuinely useful, roadside tests must be valid and reliable; i.e., they must measure changes in performance associated with alcohol and they must do it consistently. To the extent that they meet the validity and reliability criteria, they can be expected to contribute to traffic safety by increasing the likelihood that alcohol-impaired drivers will be removed from the roadway by arrest. Importantly, they also will further serve the driving public’s interests by decreasing the likelihood that a driver who is not alcohol impaired will be mistakenly detained or arrested. Thus, the validity and reliability of the tests are important issues.

Overall, for 234 cases confirmed by breath or blood tests, officers’ decisions to arrest and release were 86% correct, and 93% of their arrest decisions were correct.
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The California Study
The results of decision analyses provide clear indication of SFST accuracy. Decision analyses found that officers' estimates of whether a motorist's BAC was above or below 0.08 or 0.04 percent were extremely accurate. Estimates at the 0.08 level were accurate in 91 percent of the cases, or as high as 94 percent if explanations for some of the false positives are accepted. Officers' estimates of whether a motorist's BAC was above 0.04 but under 0.08 were accurate in 94 percent of the decisions to arrest and in 80 percent of the relevant cases, overall.

The results of this study provide clear evidence of the validity of the Standardized Field Sobriety Test Battery to discriminate above or below 0.08 percent BAC. Further, study results strongly suggest that the SFSTs also accurately discriminate above or below 0.04 percent BAC.
The Florida Study
The data obtained during this study demonstrate that 95% of the officers’ decisions to arrest drivers were correct decisions. Furthermore, 82% of their decisions to release drivers were correct. It is concluded that the SFSTs not only aid police officers in meeting their responsibility to remove alcohol-impaired drivers from the roadway, they also protect the rights of the unimpaired driver. These data validate the SFSTs as used in the State of Florida by Pinellas County Sheriff’s deputies who have been trained under NHTSA guidelines. SFST validity now has been demonstrated in Florida, California (1997) and Colorado (1995). There appears to be little basis for continuing legal challenge.
1. Dictionary.com definition
2. Merriam-Webster Dictionary
3. Regina vs STELLATO, 1994 SCC