The risk assessment by clinical background and cephalometry for obstructive sleep apnea with CPAP indication in Japanese

Obstructive sleep apnea (OSA) is a disease characterized by a brief period of cessation or marked decline in ventilation. The standard treatment is continuous positive airway pressure (CPAP). To determine the indication, full-night polysomnography (PSG) is required; however, it is a stressful examination. We verified the usefulness of pulse-oximetry at home as a predictor for CPAP indication before PSG. Simultaneously, the clinical background and cephalometry were also verified. Among 376 subjects who received PSG at our hospital from February 2005 to April 2020, 138 subjects received pulse-oximetry at home before PSG were enrolled retrospectively and performed logistic regression analysis on those with CPAP indication. Concurrently, 262 of 376 subjects received cephalometry were enrolled, and logistic regression analysis were performed using clinical background and cephalometry. A 3% oxygen desaturation (3% ODI) on the pulse-oximeter was a predictor for CPAP indication. The positive predictive value of 3% ODI ≥ 28.5 events/h was 73.3% and the negative predictive value was 62.5%. Older age, higher body mass index (BMI), stronger lower jaw retraction (wider ∠ANB), and longer distance from the anterior superior tip of the hyoid bone to the mandibular plane (MP-H) on cephalometry were also independent predictors. The positive predictive value when both BMI ≥ 26.0 kg/m2 and MP-H ≥ 17.5 mm were present was 88.2% and the negative predictive value when both were absent was 71.3%. The combination of clinical background and cephalometry would be a useful screening tool as well as a pulse-oximetry at home for CPAP indication.