A circadian and app-based personalized lighting intervention for the reduction of cancer-related fatigue

Abstract

Lighting interventions can mitigate fatigue by promoting circadian rhythmicity. We test whether individualized, wearable-based lighting interventions delivered via a mobile app reduce cancer-related fatigue in a randomized controlled trial with 138 breast cancer, prostate cancer, and hematopoietic stem cell transplant patients. Participants are randomized to tailored lighting intervention or control. The primary endpoint is PROMIS fatigue 4a at trial end, with secondary endpoints including change in daily fatigue, sleep, anxiety, depression, physical function, and overall health. Fatigue T-scores at week 11 do not differ between groups but decrease significantly from week 1 to week 11 (3.07 points, p = 0.001) in the intervention group, with a significant final-week treatment effect (p = 0.014). Daily fatigue, anxiety, sleep disturbance, and physical function improve within intervention. Further studies are needed to see if these results generalize in broader cancer care. The trial is registered at ClinicalTrials.gov (trial registration number: NCT04827446).

Keywords: cancer; cancer-related fatigue; circadian rhythm; lighting interventions; mathematical models; personalized medicine; precision medicine; wearable devices.

Graphical abstract

Figure 1

CONSORT flow diagram showing the study recruitment and reasons for exclusion Completing the study was defined as submitting some amount of survey data, not voluntarily withdrawing, and not being removed by research staff.

Figure 2

Weekly 4-item fatigue survey results (A) Mean weekly fatigue T-scores from week 1 to week 11. The control group is shown as a dashed line, and the intervention group as a solid line. Data are represented as mean, and bars denote the standard error of the mean (SEM). (B) Mean weekly fatigue T-scores, with results from the first week in the first two boxplots and the last (11th) week in the final two boxplots. Statistically significant differences (p value < 0.05) are denoted with a line and ∗. The median in each boxplot is denoted with a horizontal line, the edges in the box signify the 25th and 75th percentiles, and outliers are red plus signs. (C) Mean change in weekly fatigue from week 1 to week 11, divided by cancer population (BR, breast cancer; PR, prostate cancer; and HCT, hematopoietic cell transplant) and intervention (int) vs. control (con). Data are represented as mean, and bars denote the SEM.

Figure 3

Daily 1-item fatigue survey Responses options are “Not at all fatigued” (converted to 0), “A little bit fatigued” (converted to 1), “Somewhat fatigued” (converted to 2), and “Very fatigued” (converted to 3). (A) Daily fatigue for the intervention and control groups, considering surveys from the first week in the first two boxplots and the final (12th) week in the last two boxplots. Statistically significant differences (p value < 0.05, t test) are denoted with a line and ∗. The median in each boxplot is denoted with a horizontal line, the edges in the box signify the 25th and 75th percentiles, and outliers are given by red plus signs. (B) Mean daily fatigue value from the first to last week of the study, where the daily surveys were first binned weekly by individual. The control group is shown as a dashed line, and the intervention group as a solid line. Data are represented as mean, and bars denote the SEM.

Figure 4

PROMIS pre- and post-trial surveys, by intervention and control groups Data are shown using boxplots for (A) anxiety, (B) depression, (C) global physical health, (D) global mental health, (E) physical function, and (F) sleep disturbance. Statistically significant differences (p < 0.05) are denoted with a line and ∗. The median in each boxplot is denoted with a horizontal line, the edges in the box signify the 25th and 75th percentiles, and outliers are given by red plus signs.