Neck circumference – Height ratio cut-off as a predictor of obstructive sleep apnea severity among adult patients diagnosed with obstructive sleep apnea at the Lung Center of the Philippines

ABSTRACT

Introduction@#Obstructive sleep apnea (OSA) is the most common breathing-related sleep disorder. OSA is mainly characterized by a set of symptoms resulting from apnea events that have negative outcomes on health, such as excessive daytime sleepiness, cardiovascular impairment, and increased morbidity and mortality. It is important to develop simple, reliable, cost-effective methods to predict obstructive sleep apnea. Neck circumference - height ratio has limited studies in its relation to obstructive sleep apnea compared to neck circumference. @*Method@#This is a retrospective cross-sectional study using chart review of all patients who had been diagnosed with obstructive sleep apnea by polysomnogram at the Lung Center of the Philippines from January 2019 to December 2019. Demographic characteristics like age, gender, weight, height, neck circumference, BMI, neck circumference - height ratio [NHR], and apnea-hypopnea index were determined. Accuracy of the neck circumference - height radio cutoff had been determined in predicting obstructive sleep apnea and its severity by comparing neck - circumference - height ratio cut-off with a polysomnogram. @*Results@#Among the 384 charts collected and reviewed, this study had a total of 194 participants were included. Most participants were male (72.68%) and the age range was between 35 to 60 years old. There were 12 (6%) participants in the Mild OSA group, 19 (10%) in the Moderate OSA group, and 163 (84%) were categorized as Severe. Median Neck Circumference -Height Ratio was 0.23 to 0.26. A cutoff of > 0.23 NHR was used to predict Mild OSA showed PPV of 46.15% (24.47 to 65.98), NPV was 66.67% (50.78 to 79.49), AUC of 0.5307 (0.30 to 0.76), and accuracy of 58.06% (39.08 to 75.45). A cutoff of > 0.23 NH was used to predict Moderate OSA showed positive predictive value (PPV) was 15.94% (10.91 to 22.7), NPV of 93.6% (89.52 to 96.16), AUC of 0.6421 (0.52 to 0.77), and accuracy of 65.98% (58.85 to 72.61). A cutoff of > 0.23 HR was used to predict Severe OSA showed PPV of 15.94% (10.91 to 22.7), NPV of 93.6% (89.52 to 96.16), AUC of 0.6421 (0.52 to 0.77), and accuracy of 65.98% (58.85 to 72.61).@*Conclusion@#The HR cut-off demonstrated a moderate positive correlation with OSA, and NH increases as the apnea-hypopnea index are increased. NH cut-off of 0.23 is sufficient to predict severe OSA but has poor diagnostic accuracy for mild and moderate OSA. Moreover, the HR cut-off may also be an integral tool to predict severe OSA.