• Mohd Shahril AH Faculty of Engineering Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Malaysia
  • Mohamad Ezuan AJ Faculty of Engineering Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Malaysia
  • Norazura I Faculty of Engineering Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Malaysia
Keywords: Sleepiness, shift work, shift workers, sleep, safety, manufacturing, Malaysia


The purpose of this study was to identify the relationship between sleepiness and daily sleep amount, and its significant associated factors among shift workers of the electronics manufacturing industry in Malaysia. 300 shift workers were asked to respond to a survey on demographic information, sleepiness and daily sleep. Sleepiness was surveyed by using the Karolinska Sleepiness Scale and daily sleep was captured by using sleep diary. A total of 255 employees provided valid data for analysis. To test the hypothesis, statistical analysis was conducted using IBM SPSS program version 24. Sleepiness among shift workers found to be increased by the end of the shift. Around 30% of workers did not have an adequate amount of daily sleep. Sleepiness was found to have significant associations with age, marital status, level of education, time of shift, and working experience. Meanwhile, the amount of daily sleep obtained was only significantly associated with the age of the respondents. There is no significant relationship found between sleepiness and daily sleep of the shift workers. Shift workers in the electronics manufacturing industry in Malaysia were exposed to sleepiness at work and reduction in their daily sleep. This will increase the risk of an accident in the workplace. Appropriate intervention program should be implemented to curb this problem.


1. Wyatt WB. Shift work and the assessment and management of shift work disorder (SWD). Sleep Med Rev 2013; 17(1): 41-54.

2. Smith L, Tanigawa T, Takahashi M, Mutou K, et al. Shiftwork locus of control, situational and behavioral effects on sleepiness and fatigue in shift workers. Industrial Health 2005; 43: 151-170.

3. American Academy of Sleep Medicine. International classification of sleep disorders: diagnostic and coding manual, ICSD-3. 3rd ed. Darien, IL: American Academy of Sleep Medicine 2014.

4. Folkard S, Lombardi D, Tucker P. Shiftwork: Safety, sleepiness and sleep. Industrial Health 2005; 43: 20 -23.

5. Sneddon A, Mearns K, Flin R. Stress, fatigue, situation awareness and safety in offshore drilling crews. Safety Science 2013; 56: 80–88.

6. Simon R. Shift work disorder: clinical assessment and treatment strategies. J Clin Psyc 2012; 73(6): 20-32.

7. Roth T. Appropriate therapeutic selection for patients with shift work disorder. Sleep Med 2012; 13(4): 335-341.

8. Antunes LC, Jornada MN, Ramalho L, Hidalgo MP. Correlation of shift work and waist circumference, body mass index, chronotype and depressive symptoms. Arq Bras Endo Metabol 2010; 54(7): 652-666.

9. Williamson AM, Feyer A, Mattick RP, et al. Developing measures of fatigue using an alcohol comparison to validate the effects of fatigue on performance. Accident Analysis and Prevention 2001; 33: 313–326.

10. Dorrian J, Lamond N, Dawson D. The ability to self-monitor performance when fatigued. J Sleep Res 2000; 9(2): 137–144.

11. Howard ME, Radford L, Jackson ML, et al. The effects of a 30-minute napping opportunity during an actual night shift on performance and sleepiness in shift workers. Biological Rhythm Research 2010; 41(2): 137-148.

12. Ohayon MM. Determining the level of sleepiness in the American population and its correlates. J Psychiatr Res 2012; 46: 422–427.

13. Philip P, Akerstedt T. Transport and industrial safety, how are they affected by sleepiness and sleep restriction?. Sleep Med Rev 2006; 10: 347–356.

14. Akerstedt T, Gillberg M. Subjective and objective sleepiness in the active individual. Int J Neuro 1990; 52: 29–37.

15. Nordin M, Alfredsson L, Westerholm P. Sleep and sleepiness: impact of entering or leaving shiftwork – a prospective study. Chronobiology International 2010; 27(5): 987-996.

16. Bener A, Yildirim E, Ozkan T, Lajunen T. Driver sleepiness, fatigue, careless behaviour and risk of motor vehicle crash and injury: population based case and control study. J Traffic Transp Eng 2017; 4(5): 496 – 502.

17. Costa G, Sartori S. Ageing, working hours and work ability. Ergonomics 2007; 50(11): 1914-1930.

18. Flo E, Pallesen S, Moen BE, et al. Short rest periods between work shifts predict sleep and health problems in nurses at 1-year follow-up. Occup Environ Med 2014; 71(8): 555-561.

19. Booker LA, Magee M, Rajaratnam SMW, et al. Individual vulnerability to insomnia, excessive sleepiness and shift work disorder amongst healthcare shift workers. A systematic review. Sleep Med Rev 2018; 41: 220-233.

20. Farzianpour F, Nosrati SA, Foroushani AR, et al. Relationship between shift work and personality traits of nurses and their coping strategies. Global J Health Sci 2016; 8(5): 166-174.

21. Chou TL, Chang LI, Chung MH. The mediating and moderating effects of sleep hygiene practice on anxiety and insomnia in hospital nurses. Int J Nurs Pract 2015; 21(Suppl. 2): 9-18.

22. West SH, Ahern M, Byrnes M, Kwanten L. New graduate nurses adaptation to shift work: can we help?, J Roy Coll Nurs Aust 2007; 14(1): 23-30.

23. Portela LF, Kroning Luna C, Rotenberg L, et al. Job strain and self-reported insomnia symptoms among nurses: what about the influence of emotional demands and social support?. Bio Med Res Int 2015; 1-8.

24. Akerstedt T, Ingre M, Broman JE, Kecklund G. Disturbed sleep in shift workers, day workers, and insomniacs. Chronobiol Int 2008; 25: 333–348.

25. Conway PM, Campanini P, Sartori S, et al. Main and interactive effects of shift- work, age and work stress on health in an Italian sample of healthcare workers. Appl Ergon 2008; 39: 630–639.

26. Drake CL, Roehrs T, Richardson G, et al. Shift work sleep disorder: prevalence and consequences beyond that of symptomatic day workers. Sleep 2004; 27: 1453–1462.

27. Ursin R, Baste V, Moen BE. Sleep duration and sleep-related problems in different occupations in the Hordaland Health Study. Scand J Work Environ Health 2009; 35: 193–202.

28. Sallinen M, Harma M, Mutanen P, et al. Sleepiness in various shift combinations of irregular shift systems. Ind Health 2005; 43(1): 114-122.

29. Cotrim T, Carvalhais J, Neto C, et al. Determinants of sleepiness at work among railway control workers. Applied Ergonomics 2017; 58: 293-300.

30. Melamed S, Oksenberg A. Excessive daytime sleepiness and risk of occupational injuries in non-shift daytime workers. Sleep 2002; 25: 315–22.

31. Takahashi M, Arito H. Maintenance of alertness and performance by a brief nap after lunch under prior sleep deficit. Sleep 2000; 23(6): 813–819.

32. Ker K, Edwards PJ, Felix LM, et al. Caffeine for the prevention of injuries and errors in shift workers. Cochrane Database Syst Rev 2010; 12(5)

33. Gander PH, Marshall NS, Bolger W, Girling I. An evaluation of driver training as a fatigue countermeasure. Transp Res Part F: Traffic Psychol Behav 2005; 8(1): 47–58.
How to Cite
Mohd Shahril AH, Mohamad Ezuan AJ, & Norazura I. (2020). SLEEPINESS AND DAILY SLEEP OF MALAYSIAN SHIFT WORKERS IN ELECTRONICS MANUFACTURING INDUSTRY. Malaysian Journal of Public Health Medicine, 20(Special1), 208-215.