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NHTSA Standardized Field Sobriety Test (SFST) Interpretation Administration and Scoring

NHTSA Standardized Field Sobriety Test (SFST) Interpretation Administration and Scoring. Presented by Todd La Neve and Deandra Grant. NHTSA research began in 1975 in California (238 volunteers lab 297 field) with three final reports being published:. California: 1977 (lab study only)

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NHTSA Standardized Field Sobriety Test (SFST) Interpretation Administration and Scoring

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  1. NHTSA Standardized Field Sobriety Test (SFST) Interpretation Administration and Scoring Presented by Todd La Neve and Deandra Grant

  2. NHTSA research began in 1975 in California (238 volunteers lab 297 field) with three final reports being published: California: 1977 (lab study only) California: 1981 (lab/field study) Maryland, Washington, DC, Virginia, North Carolina 1983 (field study only) Overview: Development and Validation Validation of the Standardized Field Sobriety Tests VIII - 1

  3. One Leg Stand Finger to Nose Finger Count Walk and Turn Tracing (a paper and pencil exercise) Nystagmus (called alcohol gaze nystagmus in the final report) Volunteers Were Subjected to Six Tests: Validation of the Standardized Field Sobriety Tests VIII - 2

  4. HGN by itself was 77% accurate Walk and Turn was 68% accurate One Leg Stand was 65% accurate It would be possible to combine the results of the HGN and Walk and Turn tests and be 80% accurate Laboratory Test DataResults at .10 BAC Validation of the Standardized Field Sobriety Tests VIII - 3

  5. Standardized administrative procedures Standardized clues Standardized criteria “Standardized” Elements Validation of the Standardized Field Sobriety Tests VIII - 4A

  6. Colorado: 1995 (234 participants) Florida: 1997 (256 participants) California: 1998 (298 participants) SFST Field Validation Studies Validation of the Standardized Field Sobriety Tests VIII - 5

  7. Occurs as the eyes gaze towards the side. It is the observation of the eyes for Horizontal Gaze Nystagmus that provides the first and most accuratetest in the Standardized Field Sobriety Test battery. Although this type of nystagmus is most accurate for determining alcohol impairment, its presence may also indicate use of certain other drugs. Horizontal Gaze Nystagmus Validation of the Standardized Field Sobriety Tests VIII - 9

  8. 1. Vestibular (inner ear related) Nystagmus Rotational - nystagmus while being spun in a circle Post-rotational - nystagmus after being spun in a circle Caloric - nystagmus caused by temperature differences in the ears Positional Alcohol Nystagmus (PAN) PAN I - the BAC is higher in the blood than the BAC in the inner ear PAN II - the BAC is higher in the inner ear than in the blood Categories of Nystagmus Validation of the Standardized Field Sobriety Tests VIII - 10

  9. 2. Neural Nystagmus Optokinetic - nystagmus caused by fast moving objects Physiological - a natural nystagmus that keeps the sensory cells of the eye from tiring. These tremors are generally too small to be seen with the naked eye Horizontal - nystagmus observed as the eyes move to the side Vertical - nystagmus observed moving the stimulus up Resting - nystagmus observed while the eyes are directed forward and not moving, very high BACs Categories of Nystagmus Validation of the Standardized Field Sobriety Tests VIII - 10

  10. 3. Pathological Disorders and Diseases These include brain tumors and other brain damage or some diseases of the inner ear Categories of Nystagmus Validation of the Standardized Field Sobriety Tests VIII - 10

  11. Two Seconds Nose Left Side Three Clues of Horizontal Gaze Nystagmus 1. Lack of Smooth Pursuit • Move the stimulus to the person’s left • Movement of the stimulus should take approximately 2 seconds out and 2seconds back for each eye Validation of the Standardized Field Sobriety Tests • Check the other eye at the same speed • Repeat Supplemental

  12. At least 4 Seconds Nose Left Side Three Clues of Horizontal Gaze Nystagmus 2. Distinct and Sustained Nystagmus at Maximum Deviation • Move the stimulus to the person’s left • Hold the stimulus at the corner of the eye (no white showing) for a minimum of4 seconds Validation of the Standardized Field Sobriety Tests • Check the other eye and hold for a minimum of 4seconds • Repeat Supplemental

  13. At least 4 seconds 45 Degrees Nose Left Side Three Clues of Horizontal Gaze Nystagmus • Slowly (at least 4 seconds) move the stimulus to the person’s left 3. Onset of Nystagmus Prior to 45 Degrees Validation of the Standardized Field Sobriety Tests • If nystagmus is observed, stop and verify that the jerking continues (prior to 45 degrees) • Check the other eye and hold for same length • Repeat Supplemental

  14. 4 or more clues indicates BAC at or above 0.10 - 77% accurate (1977 NHTSA study) 4 or more clues indicates BAC at or above 0.08 - 88% accurate (1998 San Diego study) 4 Horizontal Gaze Nystagmus Test Criterion Arrest Decision Point Validation of the Standardized Field Sobriety Tests VIII - 17

  15. At least 4 Seconds Vertical Nystagmus • Move the stimulus vertically • Raise the stimulus until the individual’s eyes are elevated as far as possible and hold for approximately four seconds Validation of the Standardized Field Sobriety Tests • Repeat Supplemental

  16. (Divided Attention Test - Mental Task and Physical Task) Instruction Stage Walking Stage Walk and Turn Validation of the Standardized Field Sobriety Tests VIII - 19

  17. Walk and Turn Test Clues 1. Can’t balance during instructions 2. Starts too soon 3. Stops while walking 4. Doesn’t touch heel to toe 5. Steps off the line 6. Uses arms for balance 7. Improper turn (or loses balance on turn) 8. Wrong number of steps Validation of the Standardized Field Sobriety Tests VIII - 21

  18. 2 or more clues indicates BAC at or above 0.10 - 68% accurate (1977 NHTSA study) 2 or more clues indicates BAC at or above 0.08 - 79% accurate (1998 San Diego study) 2 Walk and Turn Test Criterion Arrest Decision Point Validation of the Standardized Field Sobriety Tests VIII - 22

  19. (Divided Attention Test - Mental Task and Physical Task) Instruction Stage Balance and Counting Stage One Leg Stand Validation of the Standardized Field Sobriety Tests VIII - 23

  20. 1. Sways while balancing 2. Uses arms to balance 3. Hops 4. Puts foot down One Leg Stand Test Clues Validation of the Standardized Field Sobriety Tests VIII - 25

  21. 2 or more clues indicates BAC at or above 0.10 - 65% accurate (1977 NHTSA study) 2 or more clues indicates BAC at or above 0.08 - 83% accurate (1998 San Diego study) 2 One Leg Stand Test Criterion Arrest Decision Point Validation of the Standardized Field Sobriety Tests VIII - 26

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