Comparative Study of Subjective and Objective Analysis in Diagnosis of Obstructive Sleep Apnea

The gold standard for diagnosis of Obstructive sleep apnea (OSA) is an overnight polysomnography (PSG). However, PSG is time consuming, labour intensive and expensive. In our country PSG is not available everywhere. Therefore, a simple and reliable method of identifying patients of OSA is important for its prompt diagnosis and treatment. This study looks at the efficacy of three questionnaires to serve as a screening test for the diagnosis of OSA in the Indian population. For the first time in India, a prospective study was conducted wherein patients with history of OSA underwent PSG and were asked to fill three questionnaires-Epworth Sleepiness Score (ESS), Berlin Questionnaire (BQ) and Stop Bang Questionnaire (SBQ). The scoring of these questionnaires were compared with the PSG results. SBQ had a high negative predictive value (NPV) and the probability of moderate and severe OSA steadily increases with higher SBQ scores. In comparison, ESS and BQ had low NPV. SBQ is a useful clinical tool to identify patients at high risk of OSA and can facilitate in the diagnosis of unrecognised OSA.