Objective structured assessment ultrasound skill scale for hyomental distance competence - psychometric study

Ultrasound assessment of the airway recently integrates the point-of-care approach to patient evaluation since ultrasound measurements can predict a difficult laryngoscopy and tracheal intubation. Because ultrasonography is performer-dependent, a proper training and assessment tool is needed to increase diagnostic accuracy. An objective, structured assessment ultrasound skill (OSAUS) scale was recently developed to guide training and assess competence. This work aims to study the psychometric properties of OSAUS Scale when used to evaluate competence in ultrasound hyomental distance (HMD) measurement.

Prospective and experimental study. Volunteers were recruited and enrolled in groups with different expertise. Each participant performed three ultrasonographic HMD evaluation. The performance was videorecorded and anonymized. Five assessors blindly rated participants' performance using OSAUS scale and a Global Rating Scale (GRS). A psychometric study of OSAUS scale as assessment tool for ultrasound HMD competence was done.

Fifteen voluntaries participated on the study. Psychometric analysis of OSAUS showed strong internal consistency (Cronbach's alpha 0.916) and inter-rater reliability (ICC 0.720; p < 0.001). The novice group scored 15.4±0.18 (mean±SD), the intermediate 14.3±0.75 and expert 13.6±0.1.25, with a significant difference between novice and expert groups (p = 0.036). The time in seconds to complete the task was evaluated: novice (90±34) (mean±SD), intermediate (84±23) and experts (83±15), with no significant differences between groups. A strong correlation was observed between OSAUS and global rating scale (r = 0.970, p < 0.001).

The study demonstrated evidence of validity and reliability. Further studies are needed to implement OSAUS scale in the clinical setting for training and assessment of airway ultrasound competence.