Quality of life, sleep and rheumatoid arthritis (QUASAR): a protocol for a prospective UK mHealth study to investigate the relationship between sleep and quality of life in adults with rheumatoid arthritis

Introduction: People with rheumatoid arthritis (RA) frequently report reduced health-related quality of life (HRQoL), the impact one’s health has on physical, emotional and social well-being. There are likely numerous causes for poor HRQoL, but people with RA have identified sleep disturbances as a key contributor to their well-being. This study will identify sleep/wake rhythm-associated parameters that predict HRQoL in patients with RA.
Methods and analysis: This prospective cohort study will recruit 350 people with RA, aged 18 years or older. Following completion of a paper-based baseline questionnaire, participants will record data on 10 symptoms including pain, fatigue, and mood twice-daily for 30 days using a study-specific mobile application (app). A tri-axial accelerometer will continuously record daytime activity and estimate evening sleep parameters over the 30 days. Every 10 days following study initiation participants will complete a questionnaire that measures disease specific (Arthritis Impact Measurement Scale 2 - Short Form (AIMS2-SF)) and generic (WHOQOL-BREF) quality of life. A final questionnaire will be completed at 60 days after entering the study. The primary outcomes are the AIMS2-SF and WHOQOL-BREF. Structural equation modelling (SEM) and latent trajectory models (LTM) will be used to examine the relationship between sleep/wake rhythm-associated parameters and HRQoL, over time.