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

This Personalized Trial will test the feasibility and effectiveness of employing technology to facilitate remote N-of-1 interventions to research participants with self-identified fatigue. Participant's initial levels of fatigue and other outcomes will be assessed in a baseline period 2 weeks in length. Participants will spend 12 weeks alternating between bright light therapy, dim light therapy, and usual care methods to treat their fatigue, while answering daily questions and wearing an activity tracker. After 14 weeks, participants will have the ability to share their opinions about the Personalized Trials platform. The investigators believe a Personalized Trials platform will be satisfactory to participants and feasible to scale to large randomized controlled trials, and eventually to clinical practice.

This Personalized Trial will test the feasibility of employing technology to facilitate remote N-of-1 interventions to research participants with self-identified fatigue. Symptoms of fatigue will be defined using the PROMIS Fatigue measures. Following a 2 week baseline assessment period, participants will be randomized in a multiple crossover design to receive bright blue light therapy, dim blue light therapy, and usual care in 6 treatment periods 2 weeks in length (12 weeks total). Participants will be randomly assigned to 2 groups receiving treatments in different order. Group 1 will receive treatments in the following order: bright light, dim light, usual care, usual care, dim light, bright light. Group 2 will receive treatments in the following order: usual care, dim light, bright light, bright light, dim light, usual care. Light therapy will be delivered using commercial available devices manufactured by AYO. The total duration of the study will be 14 weeks. During the baseline assessments and all treatment periods, participants will be assessed using daily survey measures, weekly survey measures, ecological momentary assessment (EMA) measures delivered via text message 3 times daily, and information collected via a Fitbit device. Survey measures will assess participant self-reported fatigue. EMA measures will ask participants to rate their fatigue, pain, concentration, confidence, mood, and stress in the moment. Participant daily steps and nightly sleep duration will be assessed using the Fitbit Charge 3™ device. After at the end of the study, participants will receive a personalized report summarizing their data from the baseline assessment and from each treatment period. Participants will be asked to evaluate their experience with the Personalized N-of-1 Trial overall and each element of the trial using the System Usability Scale (SUS) as well as a satisfaction survey measure. Participant adherence to study intervention devices (e.g. AYO bright blue light and AYO dim blue light machines), survey measures, EMA measures, and Fitbit device usage will also be assessed.

Eligibility Criteria:
Inclusion criteria:

* Age 18 - 59 years old of age
* Fluent in English
* Self reported fatigue results score \> 12 on a modified PROMIS Fatigue Short Form 8a scale
* Able to participate in blue light therapy
* Owns and can regularly access a smartphone capable of receiving text messages
* Owns and can regularly access an e-mail account
* Lives in the United States

Exclusion criteria:

* \<18 years old or \>60 years old
* Pregnant women
* Previous diagnosis of a serious mental health condition or psychiatric disorder, such as bipolar disorder
* Previous diagnosis of eye disease, such as cataracts, glaucoma, macular degeneration, Stargardt disease or family history of Stargardt disease, retinitis or retinopathy, or other retinal disorders
* Previous diagnosis of diabetes
* Previous eye surgery
* Sensitivity to light or use of medication causing sensitivity to light
* Epilepsy or a history of seizures
* Participation in shift work (evening/night shifts, early morning shifts, rotating shifts, etc.)