Feasibility of Light Therapy for Fatigue N-of-1 Trials

The SUS is a validated 10-item questionnaire that asks users to score each item on a Likert scale from Strongly Disagree (rating of 1) to Strongly Agree (rating of 5). The SUS will be presented to the participant as addressing the ease of use, complexity, consistency of the Personalized Trials system as a whole, from recruitment to receipt of the report. Individual results are calculated to arrive at a composite measure out of 100. Participant SUS scores will be averaged together and an overall mean will be reported with standard deviation. Higher scored values correlate to a more usable system, and therefore a better outcome.

All Daily Fatigue items are rated on a scale of 1 to 5, with higher scores indicating higher levels of fatigue. PROMIS Daily Fatigue scale scores will be converted to T-scores using methods from the PROMIS scoring manual based on item response theory. Levels of daily fatigue will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of fatigue will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in daily fatigue over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

All Weekly Fatigue items are rated on a scale of 1 to 5, with higher scores indicating higher levels of fatigue. PROMIS Weekly Fatigue scale scores will be converted to T-scores using methods from the PROMIS scoring manual based on item response theory. Levels of weekly fatigue will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of weekly fatigue will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in weekly fatigue over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Fatigue will be assessed via 3 daily text message prompts sent at random times throughout the day asking individuals to rate their fatigue on a scale of 0(low) to 10(high). Levels of EMA fatigue will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of EMA fatigue will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in EMA fatigue over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Participants will rate their satisfaction with the Personalized N-of-1 Trial overall and with individual elements of the trial in a satisfaction survey administered following the baseline and treatment periods (14 weeks). Satisfaction items are not part of an already existing scale but were developed to assess participant satisfaction with specific elements of the current study and the personalized trial overall. Participants will rate their satisfaction on a scale of 1 to 5, with higher numbers indicating greater levels of satisfaction. Means and standard deviations will be reported for each element of satisfaction.

Pain will be assessed via 3 daily text message prompts sent at random times throughout the day asking individuals to rate their pain on a scale of 0(low) to 10(high). Levels of EMA pain will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of EMA pain will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in EMA pain over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Concentration will be assessed via 3 daily text message prompts sent at random times throughout the day asking individuals to rate their concentration on a scale of 0(low) to 10(high). Levels of EMA concentration will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of EMA concentration will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in EMA concentration over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Confidence will be assessed via 3 daily text message prompts sent at random times throughout the day asking individuals to rate their confidence on a scale of 0(low) to 10(high). Levels of EMA confidence will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of EMA confidence will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in EMA confidence over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Mood will be assessed via 3 daily text message prompts sent at random times throughout the day asking individuals to rate their mood on a scale of 0(poor) to 10(excellent). Levels of EMA mood will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of EMA mood will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in EMA mood over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Stress will be assessed via 3 daily text message prompts sent at random times throughout the day asking individuals to rate their stress on a scale of 0(low) to 10(high). Levels of EMA stress will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean levels of EMA stress will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Changes in EMA stress over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Daily step counts will be assessed by a Fitbit Charge 3™ device. Daily step counts will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean daily steps will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Daily steps values over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

Nightly sleep duration will be assessed by a Fitbit Charge 3™ device. Sleep duration will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate an overall mean and standard deviation for each period. Mean sleep duration will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Sleep duration values over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.

For each participant of the proportion of surveys measures completed (both daily and weekly surveys) will be calculated. Completion rates across all participants will be reported with means and standard deviations.

For each participant of the proportion of EMA measures completed will be calculated. Completion rates across all participants will be reported with means and standard deviations.

For each participant, the proportion of days where the Fitbit device was worn will be calculated. Completion rates across all participants will be reported with means and standard deviations.

For each participant, the proportion of days where 30-minute sessions using the bright blue light device were completed will be calculated. Completion rates across all participants will be reported with means and standard deviations.

For each participant, the proportion of days where 30-minute sessions using the dim blue light device were completed will be calculated. Completion rates across all participants will be reported with means and standard deviations.

Participant self-reported side effects will be assessed utilizing a weekly survey measure. Number of side effects will be will be aggregated within the baseline assessment period and in each of the treatment periods (bright light, dim light, and usual care) to generate a count of self-reported side effects in each study period. Mean number of self-reported side effects will be compared to baseline using three paired-samples t-tests (bright light vs baseline, dim light vs baseline, usual care vs baseline). Side effects over the course of the study will also be evaluated using Generalized Linear Mixed Model analyses.