Contralateral Occlusion Test (COT): Predicting the degree of conductive hearing loss by the effect of external ear canal occlusion

Bedside testing may decrease turnaround time and improve decision making for a quick qualitative assessment of hearing loss. It was designed a bedside test with tuning forks that can allow the quantitative evaluation of hearing loss in the presence of unilateral conductive hearing loss. COT showed a better association between hearing loss and the lateralization response using the 512 Hz tuning fork (p = 0.001). The sensitivity of the 512 Hz fork in detecting a PTA of at least 35.6 dB was 94.6% and the specificity was 75.0% for a positive predictive value of 89.7% and a negative predictive value of 85.7%, assuming a pretest prevalence of 69.8%. The overall accuracy of the COT in predicting the degree of unilateral conductive hearing loss was significant. The COT had significant power in one direction: if lateralization to the affected ear occurred, it was almost certain evidence of a moderate or severe conductive hearing loss.

床旁检测（Bedside testing）可缩短检测周转时间，助力开展听力损失的快速定性评估以优化临床决策。本研究研发了一款基于音叉（tuning forks）的床旁检测方案，可针对单侧传导性听力损失（unilateral conductive hearing loss）患者实现听力损失的定量评估。采用512Hz音叉开展的COT检测显示，听力损失与偏侧反应之间存在更强的相关性（p=0.001）。若设定检测前患病率为69.8%，则512Hz音叉在检测至少35.6dB的纯音听阈（Pure Tone Audiometry, PTA）时的灵敏度为94.6%，特异度为75.0%，阳性预测值为89.7%，阴性预测值为85.7%。COT在预测单侧传导性听力损失程度方面的整体准确率具有统计学意义。此外，COT在单一判别方向上具备显著效能：若出现偏侧反应指向患耳的情况，则几乎可确诊为中度或重度传导性听力损失。