Validation of the Standardized Field Soberiety Test Battery at BACs Below 0.10 Percent

• NCJ Number: 197439
• Author(s): Jack Stuster Ph.D.; Marcelline Burns Ph.D.
• Date Published: August 1998
• Length: 21 pages
• Contract Number(s): DTNH22-95-C-05192
• Sponsoring Agency: US Dept of Transportation National Highway Traffic Safety Admin
• Corporate Author: Anacapa Sciences, Inc
• Sale Source: US Dept of Transportation National Highway Traffic Safety Admin
• Publication Format: Document
• Publication Type: Test/Measurement
• Language: English
• Country: United States of America

Annotation

This study evaluated the accuracy of the Standardized Field Sobriety Test (SFST) Battery, which is designed to assist law enforcement officers in making arrest decisions for driving while intoxicated (DWI) at blood alcohol concentrations (BACs) below 0.10 percent.

Abstract

The trend in States to reduce the statutory DWI limit to 0.08 percent BAC prompted this research. In addition to a major field study in the city of San Diego, California, the research included planning, site-selection, training, data entry, and data analysis. Seven San Diego police officers in the alcohol enforcement unit were trained in the administration and modified scoring of the National Highway Traffic Safety Administration's SFST battery. This battery consists of the horizontal gaze nystagmus-HGN, walk and turn, and one-leg stand. During routine patrols, the participating officers followed study procedures in administering SFSTs and completing a data collection form for each test administered. The officer's final step in each case was the administration of an evidentiary breath alcohol test. Analysis of the officers' data found the SFSTs to be accurate in discriminating between BACs above and below 0.08 percent. The mean estimated and measured BACs of the 297 motorists' tests were 0.117 and 0.122, respectively. Analyses of the officers' decisions regarding BAC levels above or below 0.08 or 0.04 percent were very 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 about whether a motorist's BAC was above 0.04 percent but lower than 0.08 percent were accurate in 94 percent of the decisions to arrest and in 80 percent of cases overall. The officers and prosecutors who were interviewed about the use of the SFST battery found it to be acceptable for field use in establishing probable cause for a DWI arrest. 7 figures, 13 references, and appended description of SFSTs