Validation of a Hindi version of the Epworth Sleepiness Scale (ESS) at AIIMS, New Delhi in sleep-disordered breathing

Abstract

Purpose: The Epworth Sleepiness Scale (ESS) is one of the most widely used questionnaire for the assessment of excessive daytime sleepiness (EDS) in sleep-disordered breathing (SDB). This study was conducted to assess the validity of ESS in the Hindi language.

Methods: The Hindi version was developed by translation and back translation by independent translators. The English and Hindi versions were administered to 115 bilingual subjects who presented with symptoms of SDB, of whom 98 underwent a polysomnography at a tertiary care hospital in North India.

Results: The questionnaire had a high level of internal consistency as measured by Cronbach's alpha (α = 0.84). There was no significant difference between the mean ESS scores of Hindi and English versions (11.65 ± 5.47 vs 11.70 ± 5.49, respectively; p = 0.80). The Hindi version of ESS showed a strong correlation with the English version (Spearman's correlation ρ = 0.98 and weighted kappa = 0.94). Each of the 8 individual questions of Hindi ESS demonstrated a good agreement with the corresponding English version. The Hindi ESS score was significantly higher in subjects with OSA compared to those without OSA (12.67 ± 5.29 vs 7.76 ± 5.44, respectively; p = 0.002). However, there was no difference in ESS score between mild and moderate OSA or between moderate and severe OSA.

Conclusions: The Hindi version of the ESS showed a good internal consistency and a strong correlation with the English version and can be used in the Hindi-speaking population.

Keywords: Apnea-hypopnea index (AHI); Epworth Sleepiness Scale (ESS); Obstructive sleep apnea (OSA); Obstructive sleep apnea/hypopnea syndrome (OSAHS).