RAPID3: An Effective Assessment Tool in Spondyloarthritis Save

Serial biomarker or clinical metric assessments are ubiquitous and commonly used to assess patients with rheumatoid arthritis (HAQ, CDAI, RAPID3), lupus (C3, C4, dsDNA) and gout (uric acid). But numerous disorders are either harder to assess or have tools or metrics that that are not commonly used.

Metric use in ankylosing spondylitis and spondyloarthritis has advanced significantly in the last 2 decades with the advent of the BASDAI, ASDAS and other clinical trial metrics and outcomes. However, their uptake in the clinic is largely limited to the spondyloarthritis mavens.

Investigators from France and the USA evaluated the commonly employed and simple routine assessment of patient index data (or RAPID3) to assess patients with axial spondyloarthritis (Ax-SpA).

The RAPID3 includes 3 patient self-report measures (physical function, pain and patient global estimate) and is the most commonly used practice metric to assess rheumatoid arthritis patients.

They used 461 patients in the Devenir des Spondylarthropathies Indifférenciées Récentes (DESIR) prospective cohort of patients with inflammatory back pain suggestive of Ax-SpA.  They compared RAPID3 index to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the AS Disease Activity Score (ASDAS) scores and examined therapeutic responses over 6 months. 

High level correlates were seen between the RAPID3 and BASDAI (r=0.84, p<0.005) or ASDAS-C-reactive protein (CRP) (r=0.74, p<0.005).

There was variability in the percentage of patients with inactive disease (9% to 25%) and high activity (10% to 45%) using these 3 measures, but the ability to discriminate between high and low disease activity was similar for the 3 indices.

The authors concluded that the RAPID3 index provides similar information to BASDAI and ASDAS-CRP in assessing patients with Ax-SpA and can be easily employed in outpatient clinical care.