Insomnia, anxiety, and heart rate variability among nurses working different shift systems in Taiwan.

This cross-sectional comparative study investigated the levels of insomnia, anxiety, and heart rate variability of nurses members working different shift systems. One hundred and twenty-four participants were recruited from members of the nurses of two Taiwanese hospitals. Data were collected using the Chinese versions of the Athens Insomnia Scale and Beck Anxiety Scale questionnaires and electrocardiograms recorded immediately upon completion of each participant's work shift.