An ingenious questionnaire with a high predictive value may improve OSA treatment times, according to a study published in Chest.
A clinical observation led to the development of a simple yet ingenious questionnaire for predicting which patients referred to a sleep disorders clinic will ultimately be diagnosed with obstructive sleep apnea (OSA).
“I noticed that partners of patients being investigated for OSA would often comment on being distressed at witnessing apneic spells and feel the need to poke or elbow their partner to restore regular breathing,” study co-author Mark Fenton, MD, of the University of Saskatchewan, tells Sleep Review.
As published in Chest with the title “The Utility of the Elbow Sign in the Diagnosis of OSA,” the questionnaire Fenton’s team came up with consists of these 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?
Among patients who had a polysomnogram, answering “yes” to being awakened for snoring increased the odds ratio of an OSA diagnosis by 3.9 times compared with patients who answered “no.” Answering “yes” to being awakened for apneic spells was associated with an odds ratio of 5.8 for an OSA diagnosis compared with “no.” Subjects over 50-years-old with OSA were less likely to report a positive elbow sign and had a significantly lower odds ratio for being awakened for apneic spells than those who were younger. The sensitivity and specificity of being awakened for apneic spells was 65% and 76%, respectively, with a positive predictive value of 90%.
Overall, among the study participants, the elbow sign was found to be highly specific for OSA in males with a BMI of 31 or higher, according to Fenton. He says, “A positive elbow sign nearly guaranteed a diagnosis of OSA in that group.”
Benefits and Future Use in Sleep
The advantages of this newly developed questionnaire may include improved treatment time, as well as more prompt diagnosis of OSA. “For physicians and others caring for patients with OSA, this questionnaire has the potential to improve the prediction of disease to aid in triaging waitlists,” Fenton explains. “If used in this manner, it may influence wait times for patients and has the potential to result in improved time to treatment.”
In addition, if used in a pretest clinical evaluation for OSA, this brief questionnaire may improve treatment time, which may have a positive economic impact, Fenton says, adding, “As you know, untreated OSA increases direct healthcare costs and reduces workplace productivity.”
Future research of the “elbow sign” questionnaire should be conducted in order to determine the efficacy of the questionnaire in sleep medicine practices. “The questionnaire needs to be more broadly validated as our study was from a single center,” Fenton says. In addition, since the study was done on patients referred to a sleep disorders clinic, the conclusions drawn are limited to that population, the researcher explains. “An intriguing question that arises from our data is whether in select patients this questionnaire can obviate a test. With a specificity of 97% there are very few false positives,” he says.
In regards to the application of this new questionnaire in daily sleep practice, Fenton says its use may simplify diagnosis of this sleep disorder. Fenton says, “I don’t know that I would be so bold as to say it is more effective. It has not been compared to other questionnaires. Rather I would say it is less cumbersome than some others that have multiple domains and scoring systems.”
For future use of this questionnaire in OSA diagnosis, Fenton says the questionnaire would be very easy to incorporate into a clinical history and use in the diagnosis of OSA. According to Fenton, “Although our study needs to be more broadly validated, the practical application of it is improved pre-test prediction of OSA. This can be used to inform triaging of patients waiting for testing.”
Cassandra Perez is associate editor of Sleep Review. CONTACT [email protected]