The utility of the elbow sign in the diagnosis of OSA

Abstract

Background: Multiple questionnaires have been used to predict the diagnosis of OSA. Such models typically have multiple questions requiring cumulative scoring for interpretation. We wanted to determine whether a simple two-part questionnaire has predictive value in the pretest clinical evaluation for OSA.

Methods: A questionnaire consisting of two questions--(1) Does your bed partner ever poke or elbow you because you are snoring? and (2) Does your bed partner ever poke or elbow you because you have stopped breathing?--was prospectively administered to patients evaluated in a sleep disorders clinic prior to undergoing polysomnography. Age, sex, BMI, and Epworth Sleepiness Scale data were collected.

Results: Among the 128 patients who had a polysomnogram, answering "yes" to being awakened for snoring increased the OR of an apnea-hypopnea index≥5/h 3.9 times compared with "no." Answering "yes" to being awakened for apneic spells was associated with an OR of 5.8 for an apnea-hypopnea index≥5/h compared with "no." These associations did not differ by sex, BMI, Epworth Sleepiness Scale or answering "yes" to the other question. Subjects>50 years old with OSA were less likely to report a positive elbow sign and had a significantly lower OR for being awakened for apneic spells than those<50 years old. The sensitivity and specificity of being awakened for apneic spells was 65% and 76%, respectively, with a positive predictive value of 90%. Subgroup analysis revealed that in men with a BMI>31 a positive elbow sign had a specificity of 96.6% for a diagnosis of OSA.

Conclusions: Among patients referred to a sleep disorders clinic, a positive response to being elbowed/poked for apneic spells significantly improves the pretest prediction of OSA.