Background: Sleep and rest are basic physiological human needs. Nurses work irregularly in morning, afternoon, and evening shifts; therefore, they are at greater risk of sleep problems than others. The aim of this study was to identify the factors related to sleep quality of nurses at Rafsanjan University of Medical Sciences, Iran.

Materials and Methods: This cross-sectional study was conducted in 2013. The study subjects consisted of 366 nurses who were randomly selected from among nurses working at the medical university. Data collection tools included the occupational demographic questionnaire and Pittsburgh Sleep Quality Index (PSQI). Data analysis was performed using chi-square test and logistic regression model in SPSS software.

Results: It was found that 273 (74.7%) of the nurses had poor sleep quality. The overall mean score of nurses was 7.35 ± 2.86. The logistic regression model showed a statistically significant relationship between poor sleep quality and variables of age (P = 0.030) (95% CI: 1.09-1.010) (OR = 1.50), gender (P = 0.001) (95% CI: 0.23-0.70) (OR = 0.40), number of night shifts (P = 0.003), (95% CI: 1.138-1.11) (OR = 1.20), and having children of less than one year of age (P = 0.019) (95% CI: 3.8-1.12) (OR = 2.10). The chi-square test showed a significant relationship between poor sleep quality and the type of working shift (P = 0.001). About one-third of the nurses in this study used medicine for sleeping and had difficulty in falling asleep.

Conclusions: The results indicated that the sleep quality of the majority of the nurses was poor. It is suggested that a certain guideline be developed for planning nurses’ schedules using the results of this study and other studies in this area.