The Effectiveness of Low-Level LED Light Therapy for Sleep Problems, Psychological Symptoms, and Heart Rate Variability in Shift-Work Nurses: A Randomized Controlled Trial

Abstract

Background: Shift-work schedules can cause sleep and psychological problems among nurses, negatively affecting their health and quality of life. This trial examined the effects of low-energy light therapy on sleep, psychological symptoms, and heart rate variability among shift-work nurses. Methods: This randomized controlled trial was conducted from July 2021 to June 2022. The inclusion criteria were nurses with self-reported insomnia who worked in shifts in the last 6 months in a medical center in northern Taiwan. Block randomization was used to assign the study participants to two groups: experimental (n = 32) and control (n = 32). A portable Meridian Aura Cap equipped with a low-level light-emitting diode was used to provide red and near-infrared light (660 and 850 nm) for 30 min, three times a week for 4 weeks; the control group did not receive any intervention. The Depression Anxiety Stress Scale-21 and Insomnia Severity Index were used to measure psychological symptoms and sleep problems, respectively. Heart rate variability was measured by the ANSWatch. Results: No significant differences were reported in preintervention scores. After the 4-week intervention, the intervention group scored significantly lower in insomnia (4.3 vs. 12.6, respectively; p < 0.001), depression (2.5 vs. 7.9, p < 0.001), anxiety (3.1 vs. 9.2, p < 0.001), and stress (5.6 vs. 12, p < 0.001) than those in the controls. No significant differences were observed in heart rate variability between the two groups. Conclusion: Low-level light-emitting diode light therapy improved sleep quality in shift-work nurses with insomnia and alleviated depression, anxiety, and stress symptoms; however, it did not improve heart rate variability, possibly because of the short intervention duration and the ongoing shift-work schedule. Implications for Nursing Management: Employers could consider providing phototherapy for shift nurses to improve their health. Trial Registration: ClinicalTrials.gov identifier: NCT05146596.