Table 1.

Variables and measures.

Categories and variables (frequency/source)			Definition
Demographic and baseline clinical characteristics (once at registration/ArthritisPower)
	Age	Date of birth
	Gender	Male or female
	Race	American Indian or Alaskan Native, Asian, Black or African American, Native Hawaiian or other Pacific Islander, Caucasian, multiple race, RTAa
	Hispanic ethnicity	No, unknown, yes
	Zip code	5-digit US postal code
	Condition(s)	Rheumatoid arthritis
	Years since RAb diagnosis	—c
	Rheumatologist name	National Provider Identifier lookup by city, state
	Height	—
	Weight	—
	Current medications, supplements, vitamins, over the counter, and other nonprescription remedies	DMARDd medication class for all medications taken for the treatment of RA. This attribute serves as confirmation of self-reported RA as well as a baseline covariate.
	Telephone number (cellular)	—
	Preference for email versus text notifications and reminders	—
	Typical work schedule	—
	Typical sleep schedule	—
ePROe measures
	Pain, single-item NRSf (daily/ArthritisPower)	0 (no pain) - 10 (pain as bad as it could be) at 0.5 intervals
	Fatigue, single-item NRS (daily/ArthritisPower)	0 (no fatigue) - 10 (worst possible fatigue) at 0.5 intervals
	PROMIS-CATg Fatigue (weekly/ArthritisPower)	0-100 t-score; 0 - <55 (within normal limits), 55 - <60 (mild), 60 - <70 (moderate), ≥70 (severe)
	PROMIS-CAT Pain Interference (weekly/ArthritisPower)	0-100 t-score; 0 - <55 (within normal limits), 55 - <60 (mild), 60 - <70 (moderate), ≥70 (severe)
	PROMIS-CAT Physical Function (weekly/ArthritisPower)	0-100 t-score; ≥55 (within normal limits), 40 - <55 (mild), 30 - <40 (moderate), <30 (severe)
	PROMIS-CAT Satisfaction with Participation in Discretionary Social Activities (weekly/ArthritisPower)	0-100 t-score; ≥55 (within normal limits), 40 - <55 (mild), 30 - <40 (moderate), <30 (severe)
	PROMIS-CAT Sleep Disturbance (weekly/ArthritisPower)	0-100 t-score; 0 - <55 (within normal limits), 55 - <60 (mild), 60 - <70 (moderate), ≥70 (severe)
	OMERACTh RA Flare (weekly/ArthritisPower)	0 (low) - 50 (high)
	Godin Leisure-Time Physical Activity Questionnaire (weekly/ArthritisPower)	0-23 (insufficiently active), ≥24 (active)
	Adherence to ePRO measure completion (daily or weekly/ArthritisPower)	Ratio of completed ePROs to number of required ePROs prior to discontinuation or end of study period
	Persistence with ePRO measure completion (daily or weekly/ArthritisPower)	Days until first incomplete or missing ePRO within study period
Passively collected biosensor data (continuous [if smartwatch is synced every <5 days]/Fitabase)
	Activity	Steps (minute, hour, day) Activity intensity (minute, hour, day) Distance (day) - units = miles Energy expenditure (minute, hour, day) Metabolic Equivalents (minute)
	Activity-derived variables	Time walking per day (minutes) Time in activity intensity categories per day (minutes) Active time (minutes) Aerobic time (minutes)
	Heart rate	Beats per minute (minute, day)
	Heart rate–derived variables	Time in heart rate zone of interest based on exercise charts
	Sleep	Time sleeping in last 24 hours (minute, day)
	Sleep-derived variables	Time in light, deep, and REMi sleep and time to sleep onset, time awake and other derived variables (day)
	Adherence to wearing and syncing smartwatch	Ratio of days with smartwatch data to number of days during study period prior to discontinuation or end of study period
	Persistence with wearing and syncing smartwatch	Days until first day without any smartwatch data in Fitabase

^aRTA: refuse to answer.

^bRA: rheumatoid arthritis.

^cNot applicable.

^dDMARD: Disease-Modifying Antirheumatic Drug.

^eePRO: electronic patient-reported outcome.

^fNRS: numeric rating scale.

^gPROMIS-CAT: Patient-reported outcome measurement information system-computer adaptive testing.

^hOMERACT: Outcome Measures in Rheumatology.

ⁱREM: rapid eye movement.