Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)




Exposure to light is known to produce changes within the human body. It has demonstrated ability to produce changes in the circadian rhythm and the sleep wake cycle and to change the production and secretion of melatonin and corticosteroids. The bulk of research is related to the use of bright light therapy (BLT) for certain depressive disorders. The literature does not provide a standard of care for BLT administration dose or schedule. This study intended to define any relationship between natural and ambient light with a hospitalized patient’s mood and/or fatigue level. Further it aimed to relate cumulative light levels with the hospitalized patient’s activity. In essence, it was an investigation for potential correlation between light and the independent variables of activity, mood and fatigue. If defined, there may be strength to pursue a trial utilizing BLT with a hospitalized patient population. Bone marrow transplant (BMT) patients were selected because of documented issues with mood disturbance and fatigue and because of the long hospital stay they experience during the transplant process. BMT participants were monitored at two time points for activity and completed tools to measure fatigue and mood. Monitoring devices captured light exposure and physical activity. Sample size was defined as 82 however 90 patients were enrolled. The study saw a 33% drop out rate finishing with only 60 participants. While some correlations were made between light measures and scores for mood and fatigue, the correlations were not consistent within one measurement period or between the two measurement periods. The final results are suggestive of some level of relationship however a more controlled study with a higher accrual rate would be indicated prior to proceeding

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Included in

Nursing Commons