The menstrual cycle associated with insomnia in newly employed nurses performing shift work: a 12-month follow-up study

This study aimed to investigate whether insomnia among newly-employed shift-working nurses is associated with menstrual cycle irregularity. We followed 287 nurses employed between 2015 and 2016 for 12 months. An Insomnia Severity Index (ISI) was completed to determine levels of insomnia 6 months after beginning work. At baseline and at 12-month follow-up, menstrual cycle information was obtained using clinical interviews. We analyzed baseline...