Design. A descriptive correlational design was used in this preliminary study.
Methods. Between May 2011–April 2012, data were collected from a
convenience sample of 23 women and 17 men admitted to a large academically
affiliated hospital in the United States. Over 72 hours, light exposure and sleep–
wake patterns were continuously measured with wrist actigraph/light meters for
each participant. Mood was measured daily using the Profile Of Mood States
BriefTM Form. Subjective pain scores were abstracted from medical records.