2007 National Roadside Survey of Alcohol and Drug Use by Drivers

2007 National Roadside Survey of Alcohol and Drug Use by Drivers: Drug ResultsTime ofDayDaytimeNighttimeTable 33. Drug Class Distribution by Time of Day and Age (Oral Fluid)Drug Class16-20%21-34%35-44%45-64%65+%Total%N=99 N=436 N=374 N=668 N=245 N=1,822Antidepressants 0.9% 0.2% 0.3% 0.8% 0.3% 0.5%Marijuana 4.4% 7.4% 4.8% 1.7% 0.7% 4.0%Narcotic-Analgesics 0.0% 0.7% 1.9% 2.9% 0.8% 1.7%Sedatives 0.7% 0.2% 1.4% 2.3% 4.0% 1.6%Stimulants 0.3% 2.2% 1.2% 2.2% 0.1% 1.6%Other 0.0% 0.0% 0.0% 0.7% 0.0% 0.2%More than 1 Class 0.0% 0.6% 2.1% 2.6% 0.3% 1.5%Overall Drug PositiveDaytime6.2% 11.2% 11.6% 13.3% 6.4% 11.1%Negative 93.8% 88.8% 88.4% 86.7% 93.6% 88.9%N=961 N=2,437 N=1,042 N=1,216 N=148 N=5,804Antidepressants 0.3% 0.1% 0.4% 0.1% 0.3% 0.2%Marijuana 9.8% 8.5% 4.1% 1.1% 0.0% 6.2%Narcotic-Analgesics 1.1% 0.8% 4.2% 1.4% 0.4% 1.6%Sedatives 0.0% 0.6% 1.2% 0.7% 1.3% 0.7%Stimulants 2.0% 3.6% 2.8% 4.5% 0.0% 3.3%Other 0.2% 0.5% 0.2% 0.1% 0.0% 0.3%More than 1 Class 2.7% 2.9% 2.2% 1.5% 0.0% 2.4%Overall Drug PositiveNighttime16.1% 17.1% 15.2% 9.5% 2.0% 14.6%Negative 83.9% 82.9% 84.8% 90.5% 98.0% 85.4%“More than 1 Class” – Drivers testing positive for more than one drug are only counted in this category.In this table, percentages are weighted.Driver Drug Use Prevalence by Drug Category Based onOral Fluid ResultsIn this section of the report, we display drug use prevalence results from oral fluid tests by drugcategory. The three drug categories were: illegal, prescription, and over-the-counter. Becausethere were very few positive results for over-the-counter drugs, the prescription and over-thecountercategories are combined in these tables into a single category (“Medications”).Additionally, some respondents tested positive for more than one category of drug. Thus, tablespresenting drug categories present four mutually exclusive categories: Illegal; Medications;Illegal and Medications; and Negative. So as not to double count individual positive results, anindividual’s result appears in only one of these categories. However, for example in Table 34, todetermine the proportion of daytime drivers who tested positive for illegal drugs, one could sumthe daytime values for the “Illegal” category (5.8%) and for the ” Illegal & Medications”category (0.5%) to arrive at a prevalence estimate of 6.3% of daytime drivers who were positivefor at least one illegal drug. Detailed summaries of prevalence estimates for individual drugsappear in Tables 137-140 later in the report.As previously noted, drugs may be classified in different ways depending on the use of theclassification system. For example, in NHTSA’s drug evaluation and classification (DEC)48