Developing a standardized measurement of alcohol intoxication

Abstract

Introduction: We assessed multiple examinations and assessment tools to develop a standardized measurement of alcohol intoxication to aid medical decision making in the Emergency Department.

Methods: Volunteers underwent an alcohol challenge. Pre- and post-alcohol challenge, subjects were videotaped performing three standardized clinical examinations: (1) Standardized Field Sobriety Test (SFST) examination, (2) Hack's Impairment Index (HII) examination, and (3) Cincinnati Intoxication Examination (CIE). Emergency clinicians evaluated the level of intoxication using five standardized assessment tools in a blinded and randomized fashion: (1) SFST assessment tool (range 0-18), (2) HII assessment tool (range 0-1), (3) St. Elizabeth Alcohol Intoxication Scale (STE, range 0-17), (4) a Visual Analog Scale (VAS, range 0-100), and (5) a Binary Intoxication Question (BIQ). Construct validity was assessed along with inter- and intra-rater reliability.

Results: Median scores pre- and post-alcohol challenge were: SFST 6 (interquartile range 5) and 11 (3), respectively; HII 0 (0.05), 0.1 (0.1); STE 0 (1), 1 (2); VAS 10 (22), 33 (31). For BIQ, 59% and 91% indicated intoxication, respectively. Inter-rater reliability scores were: SFST 0.71 (95% confidence interval 0.48-0.86) to 0.93 (0.88-0.97) depending on examination component; HII 0.90 (0.82-0.95); STE 0.86 (0.75-0.93); VAS 0.92 (0.88-0.94); BIQ 0.3. Intra-rater reliability scores were: SFST 0.74 (0.64-0.82) to 0.87 (0.81-0.91); HII 0.85 (0.79-0.90); STE 0.78 (0.68-0.85); VAS 0.82 (0.74-0.87); BIQ 0.71. VAS reliability was best when paired with the HII and SFST examinations.

Conclusions: HII examination, paired with either a VAS or HII assessment tool, yielded valid and reliable measurements of alcohol intoxication.