SHIFTWORK General effects & effects on performance
What will be discussed • Definition • Shiftwork effects • Case studies/ Articles: - Shiftwork experience, age and cognitive performance - Strategies for coping with shift work • Recommendations
Definition • No common definition exists • However it can be described as a system ‘where people work organizationally defined different blocks of time on a regular basis’ (Pierce et al. 1989 cited in Johnson 1999,p. 9). • It is though mostly associated with working outside the standard day shift patterns. • Usually characterised as ‘work hours that are scheduled outside daylight (6 am–6 pm) hours’, (Hughes & Stone, 2004).
What are the effects of shiftwork? • Physiological effects: - Disturbed circadian rhythms and sleep; endogenous body clock (e.g. controlling body temperature) vs. exogenous factors (e.g. controlling sleep/wake cycles) - Chronic fatigue; fatigue is cumulative - Suppression of the immune system/health problems - Individual differences contribute to the severity/type of any physiological responses & problems • Psychological effects: - Depression after a long term exposure - Stress
Effects of shiftwork (cont.) • Effects on performance: - Complexity of the task defines efficiency - Short term memory is a vital factor of performance - More complex working memory tasks (e.g. logical reasoning) improve by midday & then decline (Folkard & Monk, 1980) - Immediate retention on a task is better in the morning, however delayed retention (>7 days) is generally better during the afternoon/evening (Folkard & Monk, 1985a) - Personality types are relevant to the psychosomatic adjustment in shiftwork thus affecting performance
SW experience, age and cognitive performance Results: • Current male shift workers cognitive score >workers never did SW • SW have same effect on cognitive efficiency at every age • Difference between speed & verbal memory performance; speed performance is rapidly affected by SW while verbal memory would be impaired after several years of exposure. • Effect of shift duration; immediate recall performance decreases as SW experience increases • Possible reversibility of effects: cognitive performance of participants who stopped SW more than 4 years, seemed to be increased
Strategies for coping with shift work • Dingley 1996, Reid et al 1997; effects of fatigue; delayed reaction time, delayed responses, delayed thinking, diminished memory, failure to respond at the appropriate time, impaired efficiency & provision of false responses. • Reduced alterness can lead to clinical errors, which may compromise patients well being (landrigan et al 2004, Lockley et al 2004) • Sleep deprivation: Equivalent to a person with blood alcohol concentration of 0.10% (0.08% level in UK for driving) (Williamson and Feyer 2000) • Lee et al (2003) investigated mortality rates in NICUs: Babies born at 24-32 weeks were 60% more likely to die if born at night in comparison to babies with the same gestational age born during the day. Proposed 3 possible reasons : Performance of nursing and medical staff during night shifts linked to fatigue and circadian dysfunction resulted in inferior levels of alertness and performance.
Recommendations • Take a nap during the night/ nap rooms • Sleep in the afternoon • Environmental considerations: • - Bright lights • - Lightning & ventilation • Nutritional consideration : healthy well- balanced diet • Fixed shift • Rest Break • Use curtains, eye shades, ear plugs, switch off phone…
References • Hughes, R., & Stone, P. (2004). The perils of shiftwork: Evening shift, night shift and rotating shifts: Are they for you? American Journal of Nursing, 104(9), 60-63 • Johnson, K. (1999). Shiftwork from a work & family perspective. Applied Research Branch, Strategic Policy, Human Resources Development Canada, Hull, Quebec, Canada • Warr, P. (2002). Psychology at work. London: Penguin books • Twarog, J. (2005). Dealing with the dangers of shiftwork. Labour Department: Educating our members. Massachussets Nurse • Rouch, I., Wild, P., Ansiau, D., & Marquies, J-C. (2005). Shiftwork experience, age and cognitive performance. Ergonomics, Vol. 48, No. 10, 1282-12.93 • Peate, I., (2007). Strategies for coping with shiftwork. Nursing Standard. 22, 4, 42-45.
