Ring gauge measurements were associated with significant changes in finger joint swelling in patients with rheumatoid arthritis, according to a recent study. 

In the study, published in the Open Journal of Rheumatology and Autoimmune Diseases, the researchers evaluated the utility of a ring gauge as a simple, semiquantitative method to monitor changes in finger joint circumference in patients with rheumatoid arthritis (RA) initiating or switching biologic therapy. The study demonstrated significant reductions in joint circumferences following treatment, correlating with improvements in synovial inflammation.

The study enrolled 20 patients (18 women, 2 men; mean age = 60.5 years) with RA. Joint circumferences were measured using a ring gauge, and assessments included Gray Scale (GS) and Power Doppler ultrasonography, as well as Disease Activity Score 28 with C-reactive protein (DAS28-CRP). Measurements were performed at baseline and 28 days after biologic therapy initiation.

Joint circumference significantly decreased after treatment (P < .01). For example, the thumb’s circumference reduced from 20.1 ± 5.0 mm to 18.7 ± 5.1 mm. DAS28-CRP scores improved from 4.28 ± 1.05 to 2.72 ± 0.95 (P < .01). Reductions in ring gauge measurements were correlated with improvements in synovial thickening and blood flow as detected by ultrasonography. A receiver operating characteristic analysis identified a ring gauge cutoff value of 2 for GS changes, yielding a sensitivity of 54.5%, specificity of 71.7%, and an area under the curve of 0.70.

The study highlighted the ring gauge as a simple and accessible tool for assessing RA disease activity, offering a potential alternative to more complex imaging methods. A change of 2 or more in ring gauge measurements was associated with improvements or worsening in synovial inflammation. Although limited by a small sample size, these findings suggested potential utility warranting further study.

Full disclosures can be found in the published study.