Rheumatoid Arthritis Severity Linked to Erratic Automobile Control

RA in hand
Rheumatoid arthritis. General practitioner examining a patient’s hand for signs of rheumatoid arthritis. This condition is caused by the immune system attacking the body’s own tissues, causing progressive joint and cartilage destruction. As the cartilage is worn away, new bone grows as part of the repair process. This causes stiffness and deformity of the fingers. Treatment is with anti-inflammatory drugs and physiotherapy.
A novel longitudinal study was undertaken to assess driving performance in patients with rheumatoid arthritis.

Using in-vehicle sensor-based technology, patients with rheumatoid arthritis (RA) who had more severe disease and declining physical function exhibited more erratic braking and accelerating during highway driving, according to study data published in Arthritis Care & Research.

For patients with RA, driving is a key factor to maintain independence. Patients with arthritis commonly give up driving due to their disease. This longitudinal study was undertaken to assess driving performance in patients with RA.

Participants included patients with RA and a control group without disease. Driving assessments were completed during 2separate 4-week periods for patients with RA or a 4-week period for control participants using an in-vehicle recording device that captured video (roadway and driver) and driving data. RA disease activity and physical functioning were measured using the Clinical Disease Activity Index (CDAI) and Health Assessment Questionnaire II (HAQ-II), respectively. Vehicle control, quantified using acceleration variability in both lateral (steering) and longitudinal (braking/accelerating) planes, was the primary outcome.

During 1,292 recorded hours of driving, researchers found significant differences in vehicle control between drivers with RA (n=33) compared with drivers without disease (n=23) at higher speeds. On residential roads (20-30 mph), participants with moderate to high and low RA disease activity had lower variability in braking/accelerating than control participants (P =.004 and .001, respectively). On highways (³55 mph), drivers with moderate to high RA demonstrated increased steering variability (P =.04). In models using only data from drivers with RA increased disease activity and physical disability between baseline and 12 weeks of follow-up were associated with a significant increase in braking/accelerating (both P <.05).

Limitations of the study included an inability to assess driving-related difficulties faced by people with arthritis (vehicle entry and exit, reversing, and extended periods of sitting), use of driving aids (padded steering wheels or modified foot pedals), and use of automation technologies (cruise control). In addition, participants may have altered their driving behaviors knowing they were being observed, it was noted.

The researchers concluded, “We found that measures of vehicle control differed significantly between participants with RA and [participants] without disease and that these differences varied substantially by road type. Naturalistic observations in this study provide direct, quantitative evidence on the effects of RA on real-world performance, behavior and life space. They also offer potential digital biometric indices for assessments of RA treatment efficacy and disease status.” The investigators wrote that future work may more “precisely map arthritis manifestations and related treatments to driving risk.”


Mikuls TR, Merickel J, Gwon Y, et al. Vehicle control as a measure of real-world driving performance in patients with rheumatoid arthritis. Arthritis Care & Research. Published online August 16, 2021. doi:10.1002/acr.24769.