TORONTO – The disease burden of osteoarthritis at the time of the first visit to a rheumatologist is similar to that of a new rheumatoid arthritis patient; the big difference between the two diseases is that a year later the disease burden of RA is significantly diminished, while it remains unchanged over time in OA patients, Theodore Pincus, MD, reported at the OARSI 2019 World Congress.
These divergent trajectories of disease burden, as measured using a validated patient self-assessment instrument, reflect the far superior and more numerous therapies available for treatment of RA. It’s an unfortunate disparity, especially given that OA is more than 20 times as prevalent as RA.
But the side-by-side, patient self-reported disease burden data presented by Dr. Pincus also underscored another point: “The severity of disease burden in OA to the patient appears to be underrated by the medical community, general public, and even patients,” he said at the meeting sponsored by the Osteoarthritis Research Society International.
Dr. Pincus, a pioneer in outcomes assessment in rheumatology, is credited with codeveloping the RAPID 3 (Routine Assessment of Patient Index Data 3) score, widely utilized by rheumatologists as part of routine care in clinical practice (Bull NYU Hosp Jt Dis. 2009;67[2]:211-25).
At OARSI 2019, he presented results of a longitudinal study of disease burden over the course of 2 years in 101 patients with OA and 175 with RA who completed the Multidimensional Health Assessment Questionnaire (MDHAQ) and RAPID 3 in the waiting room before their first and all subsequent office visits with a rheumatologist. The MDHAQ, another self-assessment tool codeveloped by Dr. Pincus, is a two-page questionnaire that includes scores for pain, physical function in 10 activities, fatigue, and a self-reported painful joint count.
At the first visit with a rheumatologist, the mean MDHAQ/RAPID 3 score on a 0-30 scale was 11.9 in the OA group and 13.7 in the RA patients, a difference small enough that Dr. Pincus dismissed it as not clinically significant. After 1 year, the mean score was 11.5 in the OA group, and 2 years later it was 11.9, identical to the OA patients’ score back at their first visit. Meanwhile, the RA patients improved from 13.7 at baseline to 10.9 at 1 year and 9.0 at 2 years, according to Dr. Pincus, professor of rheumatology at Rush Medical College, Chicago.
The between-group differences over time in pain and physical function were particularly telling. Pain on a 0-10 scale stuttered from 5.0 at first visit in the OA group to 4.9 at 1 year and 4.7 at 2 years, while the RA group registered much greater improvement, going from a mean of 5.5 at first visit to 4.3 at 1 year and 3.6 at 2 years. Meanwhile, physical function worsened over time in the OA group while improving in the RA group from 0.78 at first visit to 0.66 at 1 year and 0.53 at 2 years, he noted.
Dr. Pincus reported having no financial conflicts regarding this study.