Affiliations: Qazvin University of Medical Sciences, Qazvin, Iran | Department of Occupational Medicine, Tehran University
of Medical Sciences, Tehran, Iran
Note: [] Corresponding author: Zohreh Yazdi, Department of Education,
Qazvin University of Medical Sciences, Shahid Bahonar Avenue, PO BOX: 34197
59811, Qazvin, Iran. Tel.: +98 281 3336002; Fax: +98 281 3359503; E-mail:
zyazdi@qums.ac.ir
Abstract: BACKGROUND: Morningness and eveningness preference
(chronotype), an endogenous component of the circadian clock could play a key
role in a worker's ability for adjusting to shift work. Morning types are those
individuals who prefer going to bed and waking up early, whereas Evening types
tend to sleep at later hours and find it difficult to get up in the morning. OBJECTIVE: The objective of this study was to survey, the relationship
between morningness-eveningness type, sleep quality and insomnia in shift worker nurses. PARTICIPANTS: The participants comprised 160 nurses
working in three different wards in two university hospitals in Iran. METHODS: Nurses completed the Horne and Ostberg [23] questionnaire to
assess the distribution of morningness or eveningness preference, the Pittsburg
Sleep Quality Index [22] and Insomnia Severity Index questionnaire [21]
to measure self reported sleep quality and insomnia. Demographic information
was also collected in order to explore the relationship between circadian
rhythms, sleep quality and prevalence of insomnia in shift workers. RESULTS: The results showed that the prevalence of poor sleep quality was
high. More than half of the participants had poor sleep. Evening type nurses
had worse sleep quality in our study (P < 0.05). There is not any
significant association between the shift type and age of the nurses with their
quality of sleep (P > 0.05). CONCLUSIONS: The results suggested that
nurses who had a morning sleep preference had better sleep quality. A survey of
chronotype of nurses could be useful, so that individuals may be assigned to
different shifts according to their sleep preference.
