Consistency analysis and influencing factors of performing VOTE scores for drug-induced sleep endoscopy

Abstract

Objective: To investigate the consistency of Velum, Oropharygneal, Tongue base, Epiglottis (VOTE) scores between two surgeons with similar clinical experience in obstructive sleep apnea hypopnea syndrome (OSAHS) patients with different degree of disease, and to analyze the influencing factors leading to the difference in score. Methods: This was a cross-sectional study. 64 preoperative drug-induced sleep endoscopy (DISE) videos of OSAHS patients during December 2014 to July 2018, from Nanfang Hospital, Southern Medical University were analyzed. The VOTE score was assessed single-blind by two similar experienced surgeons, and the Kappa value between the two scorers was calculated by the third researcher. According to the characteristics of the case, Fisher's exact test or chi-square test method was used to further explore the factors that influenced the consistency. Results: Sixty-four patients were divided into four groups according to the severity of the disease, including mild (7 cases), moderate (30 cases), severe(18 cases), and extremely severe (9 cases). The scores evaluated between two researchers were analysed for consistency. For mild patients, the two scorers were completely consistent in the configuration and degree of obstruction in the velum and epiglottis (Kappa=1). There was no agreement on whether obstruction or not, obstructed configuration, obstructed degree of the oropharynx and tongue base, and presence of velum and epiglottis obstruction. For moderate patients, the two scorers had a good consistency in the configuration and degree of the velum (0.61≤Kappa≤0.80), and there was no consistency in the evaluation of the degree of tongue base and epiglottis (P>0.05). The consistency of the remaining obstructed conditions in the four planes was generally or moderate (0.21≤Kappa≤0.60). For patients with severe OSAHS, the two raters were completely consistent in the evaluation of palatopharyngeal and epiglottic planes for the presence of obstruction, but there was no consistency in the degree of obstruction. Although the degree of obstruction in the oropharyngeal plane can be assessed with good consistency, the consistency of whether the plane was blocked or not was generally not high. In the assessment of other obstructive conditions in the four planes of severe patients, the agreement between the two scorers was moderate or generally. For extremely severe patients, the two scorers were completely consistent in the evaluation of the velum obstruction, but there was no consistency in the degree of obstruction of the oropharynx and tongue base, and the obstruction configuration and degree of the epiglottis. The evaluation of other obstructed conditions in the four planes is good or moderate. Among the patients with severe OSAHS, the difference in the assessment of obstruction of the oropharynx was associated with tonsil size (P<0.05). Conclusion: When physicians with similar clinical experience scored VOTE, the consistency of whether the velum and oropharyngeal planes are obstructed is related to the severity of the disease. Better consistency is observed among more severe OSAHS patients. The reason for the poor consistency of the oropharyngeal plane in severe OSAHS patients OSAHS is due to the difference of the tonsils size. For severe OSAHS patients with small tonsils, the assessment of whether the oropharynx is obstructed should be more cautious.