Modification of the Epworth Sleepiness Scale in Central China

Abstract

PurposeThe well-known excessive daytime sleepiness (EDS) assessment, Epworth Sleepiness Scale (ESS), is not consistently qualified for patients with diverse living habits. This study is aimed to build a modified ESS (mESS) and then to verify its feasibility in the assessment of EDS for patients with suspected sleep-disordered breathing (SDB) in central China.MethodsA Ten-item Sleepiness Questionnaire (10-ISQ) was built by adding two backup items to the original ESS. Then the 10-ISQ was administered to 122 patients in central China with suspected SDB [among them, 119 cases met the minimal diagnostic criteria for obstructive sleep apnea by sleep study, e.g., apnea and hypopnea index (AHI) ≥ 5 h−1] and 117 healthy central Chinese volunteers without SDB. Multivariate exploratory techniques were used for item validation. The unreliable item in the original ESS was replaced by the eligible backup item, thus a modified ESS (mESS) was built, and then verified.ResultsItem 8 proved to be the only unreliable item in central Chinese patients, with the least factor loading on the main factor and the lowest item-total correlation both in the 10-ISQ and in the original ESS, deletion of it would increase the Cronbach’s alpha (from 0.86 to 0.87 in the 10-ISQ; from 0.83 to 0.85 in the original ESS). The mESS was subsequently built by replacing item 8 in the original ESS with item 10 in the 10-ISQ. Verification with patients’ responses revealed that the mESS was a single-factor questionnaire with good internal consistency (Cronbach’s alpha = 0.86). The sum score of the mESS not only correlated with AHI (P < 0.01) but was also able to discriminate the severity of obstructive apnea (P < 0.01). Nasal CPAP treatment for severe OSA reduced the score significantly (P < 0.001). The performance of the mESS was poor in evaluating normal subjects.ConclusionThe mESS improves the validity of ESS for our patients. Therefore, it is justified to use it instead of the original one in assessment of EDS for patients with SDB in central China.

Excessive daytime sleepiness assessed by the Epworth Sleepiness Scale and its association with health related quality of life: a population-based study in China

“…Furthermore, the lifestyles and economic backgrounds of the populations in these two regions differ from those in Mainland China. Zhang et al [42] and Peng et al [43] have also developed two simplified Chinese versions of the ESS. In the former study, the researchers created a modified ESS by adding two backup items to the original ESS and forming a ten-item Sleepiness Questionnaire; however, this practice might have changed the original meaning of the scale.…”

A Comparison of Personality Characteristics and Psychiatric Symptomatology between Upper Airway Resistance Syndrome and Obstructive Sleep Apnea Syndrome

“…Given cultural differences in lifestyle, inaccuracy of the ESS based on evidence in previous studies has been suggested. 37 , 38 The number of people who drive themselves in automobiles is much smaller in Korea than in Western countries, especially among women and the elderly. Furthermore, the floor living lifestyle in Korea and Japan is different from the lifestyle of sitting in a chair in China and Western countries.…”

Validation of a modified Hindi version of the Epworth Sleepiness Scale among a North Indian population

“…[1314] Although uniformity in the questionnaires across the population, ethnic group, and languages is important to maintain comparability, variability due to the irrelevance of a question does become a dominant issue. Hence, customizing the question according to the population being tested is important.…”

“…[14] The authors of that study observed a poor response to the item 8 question and attributed this to the lack of driving experience among almost 75% of their patients. In this Chinese study also, modifications were added to the scale, based on the sociocultural characteristics of their population.…”