JMIR Publications

ABSTRACT

Background:

Large gaps exist in understanding the symptomatic and functional impact of sarcoidosis. Smartphones could be used for prospective research, especially for rare diseases where organizing large cohorts can be challenging, given their near ubiquitous ownership and ability to track objective and subjective data.

Objective:

We investigate whether smartphones could assess quality of life (QoL) and physical activity of a large cohort of individuals with sarcoidosis.

Methods:

We developed a mobile application (“Sarcoidosis App") for prospective, cross-sectional study of individuals with sarcoidosis. Individuals were recruited, consented, and enrolled entirely within the App. Surveys of sarcoidosis history, medical history, and medications were administered. Patients completed modules from the Sarcoidosis Assessment Tool, a validated patient-reported outcomes assessment of physical activity, fatigue, pain, skin symptoms, sleep, and lungs symptoms. Physical activity measured by smartphones was tracked as available.

Results:

From April 2018 to May 2020, the App was downloaded 2,558 times, and 629 enrolled (64.2% female, mean age 51 years, 81.6% white, 13.7% black). Both QoL related to physical activity (p<0.001, ρ=0.250) and fatigue (p<0.01, ρ=-0.203) correlated with actual smartphone-tracked physical activity. Nineteen percent of participants missed at least one week of school or work in an observed month due to sarcoidosis, and 44% reported finances “greatly” or “severely” affected by sarcoidosis. Sixty-three percent reported medication side effects.

Conclusions:

We demonstrate that smartphones can prospectively recruit, consent, and study physical activity, QoL, and medication usage in a large sarcoidosis cohort, using both passively collected objective data and qualitative surveys. Our study provides a model for future smartphone-enabled clinical research for rare diseases and highlights key technical challenges.