Karolinska Sleepiness Scale is not Associated with Obstructive Sleep Apnea Severity Indices in Male Taxi Drivers

Abstract views: 31 / PDF downloads: 33





Obstructive sleep apnea, daytime sleepiness, sleep testing


Objective: In the current study, we aimed to evaluate the diagnostic utility of the Karolinska Sleepiness Scale (KSS) for obstructive sleep apnea (OSA) in taxi drivers.

Methods: Forty male professional taxi drivers who participated in a driving simulator experiment in the sleep laboratory were included in the current study. All participants were asked to fill out the KSS before and after a 50-minute driving simulator task in the morning after overnight polysomnography (PSG) in the hospital. OSA was defined as an apnea-hypopnea-index (AHI) 15 events/hour on the PSG. Excessive daytime sleepiness (EDS) was defined as KSS score of at least 6.

Results: In all, only 3 cases fulfilled the criteria for EDS before the driving whereas 13 cases were sleepy after the task was completed (p <0.001). No significant association was found between KSS scores after the task and the PSG variables including total sleep time, time spent in delta sleep and REM sleep as well as OSA severity indices AHI and Oxygen Desaturation Index (ODI). The agreement between OSA and sleepiness on the KSS was calculated as 0.21 (p=0.07) indicating a very weak association. The KSS has a sensitivity of 24.1%, a specificity of 45.5%, a positive predictive value of 53.9%, a negative predictive value of 30.0%, an accuracy of 46.6% for the OSA diagnosis. The area under the curve was 0.57 (95% CI 0.39 – 0.74) for the AHI and 0.56 (95% CI 0.39 – 0.73) for the ODI, confirming a very poor performance of the KSS scores to predict AHI and ODI.

Conclusion: The KSS is not associated with the severity of the OSA indices in male taxi drivers. Objective measurements of EDS are warranted for a more precise evaluation of fitness to drive in professional drivers.


Metrics Loading ...


Howard ME, Desai AV, Grunstein RR, Hukins C, Armstrong JG, Joffe D, Swann P, Campbell DA, Pierce RJ (2004) Sleepiness, sleep-disordered breathing, and accident risk factors in commercial vehicle drivers. Am J Respir Crit Care Med. 170(9):1014-21. https://doi:10.1164/rccm.200312-1782OC

Teran-Santos J, Jimenez-Gomez A, Cordero-Guevara J, Burgos–Santander CG (1999) The association between sleep apnea and the risk of traffic accidents. N Engl J Med. 340(11):847-51. https://doi:10.1056/NEJM199903183401104

Peker Y (2016) Obstructive sleep apnea and driving risk: The current Turkish legislation, controversies, and future perspectives. Marmara Med J. 29:10-15. https://doi.org/10.5472/MMJsi.2902.03

Lal C, Weaver TE, Bae CJ, Strohl KP (2021) Excessive daytime sleepiness in obstructive sleep apnea. Mechanisms and clinical management. Ann Am Thorac Soc. 18(5):757-768. https://doi:10.1513/AnnalsATS.202006-696FR

Peker Y, Balcan B (2018) Cardiovascular outcomes of continuous positive airway pressure therapy for obstructive sleep apnea. J Thorac Dis. 10(34):4262-4279. https://doi:10.21037/jtd.2018.11.48

Sheldon, S. H., Kryger, M. H., Gozal, D., & Ferber, R. (Eds.). (2014). Principles and Practice of Pediatric Sleep Medicine: Expert Consult-Online and Print. Elsevier Health Sciences. https://doi.org/10.1016/b978-1-4557-0318-0.00060-7

Kelleher I, Lynch F, Harley M, Molloy C, Roddy S, Fitzpatrick C, Cannon M (2012) Psychotic symptoms in adolescence index risk for suicidal behavior: findings from 2 population-based case-control clinical interview studies. Arch Gen Psychiatry. 69(12):1277-83. https://doi:10.1001/archgenpsychiatry.2012.164

Demir AU, Ardic S, Firat H, Karadeniz D, Aksu M, Ucar ZZ, Sevim S, Ozgen F, Yilmaz H, Itil O (2015) Prevalence of sleep disorders in the Turkish adult population epidemiology of sleep study. Sleep Biol. Rhythm. 13:298-308. https://doi.org/10.1111/sbr.12118

Benjafield AV, Ayas NT, Eastwood PR, Heinzer R, Ip MS, Morrell MJ, Nunez CM, Patel SR, Penzel T, Pépin J-L (2019) Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis. Lancet Respir Med. 7:687-698. https://doi:10.1016/S2213-2600(19)30198-5

Amra B, Dorali R, Mortazavi S, Golshan M, Farajzadegan Z, Fietze I, Penzel T (2012) Sleep apnea symptoms and accident risk factors in Persian commercial vehicle drivers. Sleep Breath. 16:187-191. https://doi:10.1007/s11325-010-0473-x

Shahid, A., Wilkinson, K., Marcu, S., & Shapiro, C. M. (Eds.). (2012). STOP, THAT and one hundred other sleep scales. Springer Science & Business Media. https://doi.org/10.1007/978-1-4419-9893-4

Reyner L, Horne JA (1998) Falling asleep whilst driving: are drivers aware of prior sleepiness? Int J Legal Med. 111:120-123. https://doi:10.1007/s004140050131

Kaida K, Takahashi M, Åkerstedt T, Nakata A, Otsuka Y, Haratani T, Fukasawa K (2006) Validation of the Karolinska sleepiness scale against performance and EEG variables. Clin Neurophysiol. 117:1574-1581. https://doi:10.1016/j.clinph.2006.03.011

Miley AÅ, Kecklund G, Åkerstedt T (2016) Comparing two versions of the Karolinska Sleepiness Scale (KSS). Sleep Biol Rhythms.14:257-260. https://doi:0.1007/s41105-016-0048-8

Berry RB, Budhiraja R, Gottlieb DJ, Gozal D, Iber C, Kapur VK, Marcus CL, Mehra R, Parthasarathy S, Quan SF (2012) Rules for scoring respiratory events in sleep: update of the 2007 AASM manual for the scoring of sleep and associated events: deliberations of the sleep apnea definitions task force of the American Academy of Sleep Medicine. J Clin Sleep Med. 8:597-619. https://doi:10.5664/jcsm.2172

Sateia MJ (2014) International classification of sleep disorders. Chest. 146:1387-1394. https://doi:10.1378/chest.14-0970

Wong KK, Marshall NS, Grunstein RR, Dodd MJ, Rogers NL (2008) Comparing the neurocognitive effects of 40 h sustained wakefulness in patients with untreated OSA and healthy controls. J Sleep Res. 17:322-330. https://doi:10.1111/j.1365-2869.2008.00665.x

Wallström S, Balcan B, Thunström E, Wolf A, Peker Y (2019) CPAP and health-related quality of life in adults with coronary artery disease and nonsleepy obstructive sleep apnea in the RICCADSA trial. J Clin Sleep Med. 15:1311-1320. https://doi:10.5664/jcsm.7926

Bostan OC, Akcan B, Saydam CD, Tekin M, Dascı O, Balcan B. (2021) Impact of Gender on Symptoms and Comorbidities in Obstructive Sleep Apnea. Eurasian J Med. 53(1):34-39. https://doi:10.5152/eurasianjmed.2021.19233

Horne JA, Reyner LA (1995) Sleep related vehicle accidents. Bmj 310:565-567. https://doi:10.1136/bmj.310.6979.565

Powell NB, Schechtman KB, Riley RW, Li K, Guilleminault C (2002) Sleepy driving: accidents and injury. Otolaryngol Head Neck Surg. 126:217-227. https://doi:10.1067/mhn.2002.122699

Strohl KP, Brown DB, Collop N, George C, Grunstein R, Han F, Kline L, Malhotra A, Pack A, Phillips B (2013) An official American Thoracic Society Clinical Practice Guideline: sleep apnea, sleepiness, and driving risk in noncommercial drivers. An update of a 1994 Statement. Am J Respir Crit Care Med. 187:1259-1266. https://doi:10.1164/rccm.201304-0726ST

Bonsignore MR, Randerath W, Riha R, Smyth D, Gratziou C, Gonçalves M, McNicholas WT (2016) New rules on driver licensing for patients with obstructive sleep apnea: European Union Directive 2014/85/EU. J Sleep Res. 25:3-4. https://doi:10.1111/jsr.12379

Axelsson J, Åkerstedt T, Kecklund G, Lowden A (2004) Tolerance to shift work—how does it relate to sleep and wakefulness? Int Arch Occup Environ Health. 77:121-129. https://doi:10.1007/s00420-003-0482-1

Ingre M, Kecklund G, Åkerstedt T, Kecklund L (2004) Variation in sleepiness during early morning shifts: a mixed model approach to an experimental field study of train drivers. Chronobiol Int. 21:973-990. https://doi:10.1081/cbi-200036895

Suhner A, Schlagenhauf P, Johnson R, Tschopp A, Steffen R (1998) Comparative study to determine the optimal melatonin dosage form for the alleviation of jet lag. Chronobiol Int. 15:655-666. https://doi:10.3109/07420529808993201

Gillberg M, Kecklund G, Åkerstedt T (1994) Relations between performance and subjective ratings of sleepiness during a night awake. Sleep 17:236-241. https://doi:10.1093/sleep/17.3.236

Kräuchi K, Cajochen C, Wirz‐Justice A (2004) Waking up properly: is there a role of thermoregulation in sleep inertia? J Sleep Res. 13:121-127. https://doi:10.1111/j.1365-2869.2004.00398.x

Åkerstedt T, Peters B, Anund A, Kecklund G (2005) Impaired alertness and performance driving home from the night shift: a driving simulator study. J Sleep Res. 14:17-20. https://doi:10.1111/j.1365-2869.2004.00437.x

Belz SM, Robinson GS, Casali JG (2004) Temporal separation and self-rating of alertness as indicators of driver fatigue in commercial motor vehicle operators. Hum Factors. 46:154-169. https://doi:10.1518/hfes.

Otmani S, Pebayle T, Roge J, Muzet A (2005) Effect of driving duration and partial sleep deprivation on subsequent alertness and performance of car drivers. Physiol Behav. 84:715-724. https://doi:10.1016/j.physbeh.2005.02.021




How to Cite

Çelik, Y. (2023). Karolinska Sleepiness Scale is not Associated with Obstructive Sleep Apnea Severity Indices in Male Taxi Drivers. European Journal of Therapeutics, 618–626. https://doi.org/10.58600/eurjther1794



Original Articles