Application of Neck Circumference in Four-Variable Screening Tool for Early Prediction of Obstructive Sleep Apnea in Acute Ischemic Stroke Patients.

BACKGROUND

The purpose of this study was to validate and pilot the use of the four-variable screening tool (4V) and modified 4V tools to identify acute ischemic stroke and transient ischemic attack (TIA) patients at high risk of obstructive sleep apnea (OSA).

METHODS

Two modified scales, 4V-1 (ie, using neck circumference instead body mass index, regardless of gender) and 4V-2 (ie, as above but scored differently according to gender) were designed. These tools were used in a consecutive cohort of 124 acute ischemic stroke/TIA patients, together with the 4V-1, 4V-2, 4V, as well as the STOP-BANG, the Berlin questionnaire, and the Epworth Sleepiness Scale (ESS). Objective level 2 or level 3 polysomnography was used to confirm OSA and its severity. Both questionnaires and polysomnography were completed within 1 week from symptom onset.

RESULTS

Area under the curve (AUC) of 4V was 0.807 (P< .0001) while AUC of STOP-BANG, Berlin Questionnaire and ESS were .701 (P< .0001), .704 (P< .0001) and .576 (P = .1556), respectively. AUC of 4V was greater than of STOP-BANG (z = 2.200, P = .0220), Berlin (z = 2.024, P = .0430) and ESS (z = 3.363, P = .0003). AUC of modified 4V-1 and modified 4V-2 were .824 (P< .001) and .835 (P< .001), respectively. Performance of modified 4V-2 was higher versus modified 4V-1 (z = 2.111, P = .0348) and higher but not significantly so to regular 4V (z = 1.784, P = .0744).

CONCLUSIONS

Neck circumference scored by gender is a useful substitution to body mass index in the 4V when screening OSA at early stages of ischemic stroke/TIA patients.