TOPLINE: 

Integrating passive smartphone data with patient‑reported outcomes (PROs) can help detect flares early in patients with rheumatoid arthritis (RA). In this study, reduced mobility and shorter text messages were associated with higher odds of self‑reported flares, suggesting that digital behaviors may signal disease activity.

METHODOLOGY:

• Researchers conducted this study to characterize flare frequency and severity in patients with RA and to examine whether short‑term changes in PROs, together with passive smartphone data, were associated with self‑reported flares.
• They enrolled 292 patients with RA from a US registry of patients with rheumatic diseases who agreed to share their own PROs and passive smartphone data, including mobility and communication patterns.
• PROs included daily measures of pain and function and weekly assessments of pain and global health.
• The study comprised two phases: a conditional phase in which flare questions were administered based on changes in PROs, and a fixed phase in which flare questions were presented every 2 weeks regardless of PRO values; participants reported flares via the app question, "Are you currently experiencing a flare?"
• The conditional phase had 131 participants, of whom 57 also entered the fixed phase, in which new participants were also included.

TAKEAWAY:

• During the conditional phase, 71% of patients reported one or more flares over a median of 441 days, whereas 76% reported flares in the fixed phase over a median of 172 days; the average number of flares per participant was 2.9 in the conditional phase vs 3.7 in the fixed phase, corresponding to three and nine flares per year, respectively.
• Across both phases, mobility radius and the length of text messages were longer in weeks when participants did not report a flare, whereas reaction time — defined as the number of hours between the app prompt and the participant's response — was longer in weeks with self‑reported flares.
• Greater mobility radius was linked to lower odds of flares in the conditional phase (odds ratio [OR], 0.88; 95% CI, 0.80-0.97), as were shorter reaction times and responding on weekdays.
• In the fixed phase, greater text-message length was protective against flares (OR, 0.68; 95% CI, 0.50-0.92), as was the summer season. Worse pain and patient global visual analog scores were each linked to a greater likelihood of experiencing a flare.

IN PRACTICE:

“This study represents an innovative step in bridging traditional RA assessment methods with emerging digital health technologies to enhance the understanding and management of RA flare,” the authors wrote.

SOURCE:

The study was led by Elizabeth Mollard, PhD, University of Nebraska Medical Center in Omaha. It was published online on January 12, 2025, in ACR Open Rheumatology.

LIMITATIONS: 

Continuously evolving smartphone usage patterns may have affected applicability of these data. Passive data collection was limited to Android users. Additionally, the sample comprised 90% women, potentially limiting generalizability to men with RA.

DISCLOSURES:

The authors declared no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.