Jana Volná, Karel Šonka
Charles University and General University Hospital, 1st Faculty of Medicine, Department of Neurology, Prague, Czech Republic

Korespondenční autor: Jana Volná (

ISSN 1804-7181 (On-line)

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Submitted:25. 9. 2010
Published online: 27. 12. 2010


Shift work is associated with increased risk of health problems. We chose to test the parameters of wakefulness at shift-working nurses using the Performance Vigilance Task (PVT-192). The visual analogue scale of sleepiness (VAS) and selected sleep history data were included in the investigation.

20 nurses working in a 12-hour rotating shift regimen were included. Exclusion criteria comprised the use of sleep-modulating drugs, the presence of history-based sleep disorders, morbidity. Each of the nurses underwent a total of four PVT tests, before and then after her (day or night) duty.

The reaction time (RT) mean value before the day shift was 261.3ms (SD±38.7), after the day shift 260.1ms (SD±33.1), before the night shift 251.3ms (SD±23.5), after the night shift 260.5ms (SD±26.1). There were significant differences in RT before and after the night duty, and between the RT of both evening measurements. The difference in RT before and after duty was significantly greater after night shifts.

There was a significant difference between the rate of PVT test errors before the day shift and after the night shift.

VAS-based subjective rating of daytime sleepiness was 3.3 (SD±2.2) before and 3.5 (SD±2.8) after the day shift, 3.1 (SD±2.4) before and 5.9 (SD±2.3) after the night shift. There was a significant difference between VAS before and after night shifts, and a significant difference in the VAS difference between the beginning and end of the night shift in comparison with the day shift. Clearly enough, the circadian aspect has a major role to play in the testing.

Keywords: shift work; sleep disorders; PVT; reaction time; errors


1. Akerstedt T (1985). Adjustment of physiological circadian rhythms and the sleep-wake cycle to shiftwork. In Folkard S, Monk TH, editors: Hours of Work: Temporal Factors in Work scheduling. New York: Wiley, p. 185–197.

2. Akerstedt T (1988). Sleepiness as a consequence of shift work. Sleep. 11: 17–34.

3. Akerstedt T (2003). Shift work and disturbed sleep/wakefulness. Occup Med (Lond). 53: 89–94.

4. Akerstedt T, Peters T, Anund A, Kecklund G (2005). Impaired alerteness and performance while driving home from the night shift: a driving simulator study. J Sleep Res. 14: 17–20.

5. American Academy of Sleep Medicine (2005). International Classification of Sleep Disorders: Diagnostic and Coding Manual. Illinois: Westchester, 2nd ed.

6. Bjerner B (1949). Alpha depression and lowered pulse rate during delayed actions in a serial reaction test. Acta Physiol Scand. 19: 1–93.

7. Boggild H, Knutsson A (1999). Shift work, risk factors and cardiovascular disease. Scand J Work Environ Health. 25: 85–89.

8. Carskadon MA, Dement WC, Mitler MM, Roth T, Westbrook PR, Keenan S (1986). Guidelines for the Multiple Sleep Latency Test (MSLT): A standard measure of sleepiness. Sleep. 9: 519–524.

9. Dinges DF, Powell JW (1985). Microcomputer analyses of performance on a portable, simple visual RT task during sustained operations. Behavior Research, Methods, Instruments and Computers. 17: 652–655.

10. Drake CL, Roehrs T, Richardson G, Walsh JK, Roth T (2004). Shift work sleep disorder: prevalence and consequences beyond that of symptomatic day workers. Sleep. 27: 1453–1462.

11. Gold DR, Rogacz S, Bock N, Tosteson TD, Baum TM, Speizer FE et al. (1992). Rotating shift work, sleep, and accidents related to sleepiness in hospital nurses. Am J Public Health. 82: 1011–1014.

12. Hastings MH, Reddy AB, Maywood ES (2003). A clockwork web: circadian timing in brain and periphery, in health and disease. Nat Rev Neurosci. 4: 649–661.

13. Knauth P, Landau K, Dröge C, Schwitteck M, Widynski M, Rutenfranz J (1980). Duration of sleep depending on the type of shift work. Int J Occup Environ Health. 46: 111–125.

14. Knutsson A (2003). Health disorders of shift workers. Occup Med (Lond). 53: 103–108.

15. Landrigan CP, Rothschild JM, Cronin JW, Kaushal R, Burdick E, Katz JT et al. (2004). Effect of reducing interns’work hours on serious medical errors in intensive care units. N Engl J Med. 351: 1838–1848.

16. Reyner LA, Horne JA (1998). Falling asleep whilst driving: are drivers aware of prior sleepiness? Int J Legal Med. 111: 120–123.

17. Rogers A, Holmes S, Spencer M (2001). The effect of shiftwork on driving to and from work. J Hum Ergol (Tokyo). 30: 131–136.

18. Schernhammer ES, Laden F, Speizer FE, Willett WC, Hunter DJ, Kawachi I et al. (2001). Rotating night shifts and risk of breast cancer in women participating in the nurses health study. J Nat Cancer Inst. 93: 1563–1568.

19. Steele MT, Ma OJ, Watson WA, Thomas HA, Muelleman RL (1999). The occupational risk of motor vehicle collisions for emergency medicine residents. Acad Emerg Med. 6: 1050–1053.

20. Tasto DL, Colligan MJ (1978). Health Consequences of shift work (Project UR11–4426). California: Menlo Park, Stanford Research Institute.

21. Turek FW (2005). Disorders of Chronobiology. In Kryger MH, Roth T, Dement WC, editors: Principles and Practice of Sleep Medicine. Philadelphia: Elsevier Saunders, 4th ed., p. 656–700.

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