Does obstructive sleep apnea correlate with Epworth Sleepiness Scale in an Indian population?

Various demographic and clinical predictors attributing to the severity of obstructive sleep apnea (OSA) in Indian subjects have not been extensively studied. Therefore, we aimed to study the various demographic, clinical and other predictors, if any, to corroborate the severity of OSA in the Indian population. We also validated the Epworth Sleepiness Scale (ESS) in the South Indian population, thereby assessing its utility in measuring excessive day time sleepiness (EDS) in this population which has not hitherto been performed. We recruited 145 consecutive subjects with polysomnography (PSG)-proven OSA attending our Comprehensive Sleep Disorder Clinic. Their demographic and clinical details were extracted using a standard proforma and EDS was assessed using ESS. We observed that EDS assessed by ESS positively correlated with the severity of OSA, and increasing body mass index (BMI) but not with age. We also noted that men were more prone to severe OSA than females. When individual questions of ESS were analyzed, only 3 out of 8 were able to strongly differentiate mild-to-moderate OSA from the severe group. We concluded that, severity of OSA correlated well with ESS, but not with age and BMI in Indian population and ESS could be a good indicator to assess the severity of EDS.