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Reliability and validity studies of the Turkish version of the Epworth Sleepiness Scale

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Abstract

The Epworth Sleepiness Scale (ESS) is a self-administered eight-item questionnaire that is widely used in English speaking countries for assessment of daytime sleepiness in adults. The aim of this study was to investigate the reliability and validity of the ESS in the Turkish language. The Turkish version of the ESS (ESStr) was applied to 194 healthy controls and 150 consecutive subjects attending the sleep centre with symptoms of sleep-disordered breathing. Test–retest reliability of the ESStr was tested in a separate group of 30 subjects. The ESStr scores of 60 subjects with mild to severe obstructive sleep apnoea (OSA) were compared with the ESStr scores of 60 healthy controls matched for age, gender, and body mass index (BMI). Concurrent validity with the Functional Outcomes of Sleep Questionnaire (FOSQtr) was also assessed in 12 subjects. The questionnaire had a high level of internal consistency as measured by Cronbach’s alpha (≥0.86). The test–retest intraclass correlation coefficient was r  = 0.81 (95% confidence interval: 0.64–0.90) (p < 0.001) and Spearman’s correlation coefficient was r = 0.80 (p = 0.01). The control group had lower ESStr scores than subjects with sleep-disordered breathing (3.6 ± 3 vs 12.6 ± 6, respectively; p < 0.001). Subjects with mild sleep-disordered breathing also had lower scores of the ESStr than those with moderate and severe sleep-disordered breathing (10 ± 6.2 vs 14 ± 5. and 10 ± 6.2 vs 16 ± 5.4, respectively; both p < 0.05), but there were no significant differences between moderate and severe subjects with sleep apnoea. There were significant correlations between the ESStr and total FOSQtr and its subscales (r  = −0.22 to r = −0.92; all p  = 0.05). Factor analysis of item scores showed that the ESStr had only one factor. The ESStr is a reliable and valid measure of daytime sleepiness. These features and the simplicity of the ESStr make it a valuable measure for clinical management and research.

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References

  1. Engleman HM, Douglas NJ (2004) Sleep 4: sleepiness, cognitive function, and quality syndrome of life in obstructive sleep apnoea/hypopnoea. Thorax 59:618–622

    Article  PubMed  CAS  Google Scholar 

  2. Guilleminault C, Abad VC (2004) Obstructive sleep apnea syndromes. Med Clin North Am 88(3):611–630

    Article  PubMed  Google Scholar 

  3. Douglas NJ (2001) Excessive daytime sleepiness and the sleep apnoea/hypopnoea syndrome: a major public health problem? Monaldi Arch Chest Dis 56(1):64–66

    PubMed  CAS  Google Scholar 

  4. Young T, Peppard PE, Gottlieb DJ (2002) Epidemiology of obstructive sleep apnea: a population health perspective. Am J Respir Crit Care Med 165(9):1217–1239

    Article  PubMed  Google Scholar 

  5. Johns MW (1991) A new method for measuring daytime sleepiness: the Epworth Sleepiness Scale. Sleep 14(6):540–545

    PubMed  CAS  Google Scholar 

  6. Johns MW (1994) Sleepiness in different situations measured by the Epworth Sleepiness Scale. Sleep 17(8):703–710

    PubMed  CAS  Google Scholar 

  7. Engleman HM, Martin SE, Kingshott RN, Mackay TW, Deary IJ, Douglas NJ (1998) Randomised placebo controlled trial of daytime function after continuous positive airway pressure (CPAP) therapy for the sleep apnoea/hypopnoea syndrome. Thorax 53(5):341–345

    Article  PubMed  CAS  Google Scholar 

  8. Engleman HM, McDonald JP, Graham D, Lello GE, Kingshott RN, Coleman EL, Mackay TW, Douglas NJ (2002) Randomized crossover trial of two treatments for sleep apnea/hypopnea syndrome: continuous positive airway pressure and mandibular repositioning splint. Am J Respir Crit Care Med 166(6):855–859

    Article  PubMed  Google Scholar 

  9. Faccenda JF, Mackay TW, Boon NA, Douglas NJ (2001) Randomized placebo-controlled trial of continuous positive airway pressure on blood pressure in the sleep apnea-hypopnea syndrome. Am J Respir Crit Care Med 163(2):344–348

    PubMed  CAS  Google Scholar 

  10. Johns MW (1992) Reliability and factor analysis of the Epworth Sleepiness Scale. Sleep 15(4):376–381

    Google Scholar 

  11. Chervin RD, Aldrich MS, Pickett R, Guilleminault C (1997) Comparison of the results of the Epworth Sleepiness Scale and the Multiple Sleep Latency Test. J Psychosom Res 42(2):145–155

    Article  PubMed  CAS  Google Scholar 

  12. Johns MW (2000) Sensitivity and specificity of the multiple sleep latency test (MSLT), the maintenance of wakefulness test and the Epworth Sleepiness Scale: failure of the MSLT as a gold standard. J Sleep Res 9(1):5–11

    Article  PubMed  CAS  Google Scholar 

  13. American Sleep Disorders Association (1997) Practice parameters for the indications for polysomnography and related procedures. Polysomnography Task Force, American Sleep Disorders Association Standards of Practice Committee. Sleep 20(6):406–422

    Google Scholar 

  14. Rechtschaffen A, Kales A (1973) A manual of standardized terminology, techniques and scoring system for sleep stages of human subjects. National Institute of Health (USA) publication no. 204. Brain Information Service/Brain Research Institute, University of California, Los Angeles, California

  15. American Academy of Sleep Medicine Task Force (1999) Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research. Sleep 22:667–689

    Google Scholar 

  16. Gould GA, Whyte KF, Rhind GB, Airlie MA, Catterall JR, Shapiro CM, Douglas NJ (1988) The sleep hypopnea syndrome. Am Rev Respir Dis 137(4):895–898

    PubMed  CAS  Google Scholar 

  17. Izci B, Firat H, Ardic S, Kokturk O, Gelir E, Altinors M (2004) Adaptation of functional outcomes of sleep questionnaire (FOSQ) to Turkish population. Tuberk Toraks 52(3):224–230

    PubMed  Google Scholar 

  18. Weaver TE, Laizner AM, Evans LK, Maislin G, Chugh DK, Lyon K, Smith PL, Schwartz AR, Redline S, Pack AI, Dinges DF (1997) An instrument to measure functional status outcomes for disorders of excessive sleepiness. Sleep 20(10):835–843

    PubMed  CAS  Google Scholar 

  19. Streiner DL, Norman GR (1995) Reliability and validity. Health measurement scales: a practical guide to their development and use, 2nd edn. Oxford University Press, Oxford, pp 104–161

    Google Scholar 

  20. Guyatt GH, Bombardier C, Tugwell PX (1986) Measuring disease-specific quality of life in clinical trials. CMAJ 134(8):889–895

    PubMed  CAS  Google Scholar 

  21. Bloch KE, Schoch OD, Zhang JN, Russi EW (1999) German version of the Epworth Sleepiness Scale. Respiration 66(5):440–447

    Article  PubMed  CAS  Google Scholar 

  22. Chen NH, Johns MW, Li HY, Chu CC, Liang SC, Shu YH, Chuang ML, Wang PC (2002) Validation of a Chinese version of the Epworth Sleepiness Scale. Qual Life Res 11(8):817–821

    Article  PubMed  Google Scholar 

  23. Cronbach LJ (1951) Coefficient alpha and the internal structure of tests. Psychometrika 16:297–334

    Article  Google Scholar 

  24. Gottlieb DJ, Yao Q, Redline S, Ali T, Mahowald MW (2000) Does snoring predict sleepiness independently of apnea and hypopnea frequency? Am J Respir Crit Care Med 162:1512–1517

    PubMed  CAS  Google Scholar 

  25. Johns MW (1993) Daytime sleepiness, snoring, and obstructive sleep apnea. The Epworth Sleepiness Scale. Chest 103(1):30–36

    Article  PubMed  CAS  Google Scholar 

  26. Chervin RD, Aldrich MS (1999) The Epworth Sleepiness Scale may not reflect objective measures of sleepiness or sleep apnea. Neurology 52(1):125–131

    PubMed  CAS  Google Scholar 

  27. Fong S, Ho C, Wing Y (2005) Comparing MSLT and ESS in the measurement of excessive daytime sleepiness in obstructive sleep apnoea syndrome. J Psychosom Res 58(1):55–60

    Article  PubMed  CAS  Google Scholar 

  28. Kingshott RN, Engleman HM, Deary IJ, Douglas NJ (1998) Does arousal frequency predict daytime function? Eur Respir J 12(6):1264–1270

    Article  PubMed  CAS  Google Scholar 

  29. Martin SE, Engleman HM, Kingshott RN, Douglas NJ (1997) Microarousals in patients with sleep apnoea/hypopnoea syndrome. J Sleep Res 6(4):276–280

    Article  PubMed  CAS  Google Scholar 

  30. Ferrer M, Vilagut G, Monasterio C, Montserrat JM, Mayos M, Alonso J (1999) Measurement of the perceived impact of sleep problems: the Spanish version of the functional outcomes sleep questionnaire and the Epworth sleepiness scale. Med Clin (Barc) 113(7):250–255

    CAS  Google Scholar 

  31. Gooneratne NS, Weaver TE, Cater JR, Pack FM, Arner HM, Greenberg AS, Pack AI (2003) Functional outcomes of excessive daytime sleepiness in older adults. J Am Geriatr Soc 51(5):642–649

    Article  PubMed  Google Scholar 

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Acknowledgements

Thank you very much to all the subjects who gave their time for this study. Thanks are also due to Dr. Jon Balserak for reviewing the text to ensure that the level of English is good.

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Correspondence to Bilgay Izci.

Appendices

Appendix A: The Epworth Sleepiness Scale

How likely are you to doze off or fall asleep in the following situations, in contrast to feeling just tired? This refers to your usual way of life in recent times. Even if you have not done some of these things recently, try to work out how they would have affected you. Use the following scale to choose the most appropriate number for each situation.

Scale

  • 0 = would never doze

  • 1 = slight chance of dozing

  • 2 = moderate chance of dozing

  • 3 = high chance of dozing

Situation

Chance of dozing (enter number below)

Sitting reading

 

Watching TV

 

Sitting, inactive in a public place (e.g. a theatre or a meeting)

 

As a passenger in a car for an hour without a break

 

Lying down to rest in the afternoon when circumstances permit

 

Sitting and talking to someone

 

Sitting quietly after lunch without alcohol

 

In a car, when stopped for a few minutes in the traffic

 
  1. TOTAL....................

Appendix B: Turkish version of Epworth Sleepiness Scale

Son zamanlarda, günlük yaşantınız içinde, aşağıda belirtilen durumlarda hangi sıklıkla uyuklarsınız (buradan yorgun hissetmek değil, uyuklamak veya uyuya kalmak anlaşılmalıdır)? Bu şeylerden birini son zamanlarda yapmamış olsanız bile, böyle bir durumun, sizi nasıl etkileyeceğini düşünmeye çalışarak cevap veriniz.

Ölçekteki herbir DURUM için, aşağıdaki ifadelere karşılık gelen sayılardan, sizin için en uygununu isaretleyiniz.

  • 0 = hiçbir zaman uyuklamam

  • 1 = nadiren uyuklarım

  • 2 = zaman zaman uyuklarım

  • 3 = büyük olasılıkla uyuklarım

Table 6

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Izci, B., Ardic, S., Firat, H. et al. Reliability and validity studies of the Turkish version of the Epworth Sleepiness Scale. Sleep Breath 12, 161–168 (2008). https://doi.org/10.1007/s11325-007-0145-7

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  • DOI: https://doi.org/10.1007/s11325-007-0145-7

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