Development of Screening Test for Prediction of Sleep Apnea Syndrome

Objective : Patients with sleep apnea should be diagnosed with polysomnography(PSG). However, it is not easy to recommend PSG for all patients suspected with sleep apnea in practice. Therefore, we tried to develop the screening test for referral of PSG. Method : 140 patients with snoring and sleep apnea syndrome were studied by the PSG. Sleep apnea questionnaire. Zung's scale for depression. Stanford Sleepiness Scale(SSS), insomnia scale and neuropsychological test were administered. Also, blood pressure, height, weight and neck circumference were measured and some histories were taken. Correlations between respiratory disturbance index(RDI) and various parameters mentioned above and discriminant coefficients of the parameters to RDI were computed. And, we investigated sensitivities of screening tests for selection of the patients with RDI above 20. Results : Using six parameters(neck circumference, systolic blood pressure before sleep, degree of alcohol drinking, frequency of breath-holding during sleep, degree of dry mouth during sleep, sleep apnea score), the patients with RDI above 20 could be discriminated in 92.8% sensitivity. In case of more than two among six parameters(neck circumference of above 40cm, systolic blood pressure of above 125mmHg, frequent alcohol drinking, frequent breath-holding during sleep, frequent dry mouth during sleep, sleep apnea score of above 35), same patients could be discriminated in 87.6% sensitivity. And, in case of more than one among four parameters(neck circumference of above 40cm. systolic blood pressure of above 125mmHg, frequent alcohol drinking, body weight of above 80kg), discrimination sensitivity was 83.5%. Conclusions : Patients with RDI above 20 could be discriminated by above parameters with high sensitivity. Therefore, the screening test using above parameters can be applied in selection of the patients with sleep apnea for PSG in practice.ope