Background RA generally is regarded by physicians and the public as a more severe problem than OA. However, OA has been ranked as the 11th (1) and RA as the 42nd (2) highest contributor to global disability among all diseases, and costs of OA and RA each have been found to account for about 1% of the US gross domestic product (3). These similarities of OA and RA are explained in part by the higher prevalence of OA compare to RA. Nonetheless, the standardized mortality ratio (SMR) (which is independent of prevalence) for OA is 1.55 (4), and quite similar to the SMR for RA of 1.5-1.6 (5). Therefore, the severity of OA may be underestimated.
Objectives To compare self-report scores of patients with a primary diagnosis of osteoarthritis (OA) or rheumatoid arthritis (RA) at 4 rheumatology clinical settings, according to data from a quantitative multidimensional health assessment questionnaire (MDHAQ)/routine assessment of patient data 3 (RAPID3) and physician global estimate.
Methods Patients were seen in routine care at 4 clinical settings: Liverpool Hospital, New South Wales (NSW), Australia, Rush University Medical Center, Chicago, IL, USA, NYU Medical Center, New York, NY, USA, and Arthritis and Rheumatology, a solo private practice, Ridley Park, PA, USA. At each site, patients complete an MDHAQ at each visit in the waiting area while waiting to see the rheumatologist. The MDHAQ includes scores for physical function (0-10), pain (0-10), and patient global estimate (0-10), and RAPID3 composite scores of these 3 RA core data set measures (0-30), as well as fatigue (0-10). The physician assigns a global estimate for each patient. Patients at each site with OA versus RA were compared for mean and median MDHAQ scores for demographic measures, 5 MDHAQ patient self-report measures, and physician global estimates.
Results Median scores for patients with OA were higher than for RA for 21 of 24 comparisons (6 variables, physical function, pain, patient global estimate, RAPID3, fatigue, and physician global estimate, in each of 4 settings): all 6 for Liverpool and Ridley Park, 5/6 at Rush, and 4/6 at NYU. Median physical function scores ranged from 1.7 to 2.7 for RA and 1.7 to 3.3 for OA. Median pain scores ranged from 4 to 5 for RA and 5 to 7 for OA. Median patient global estimates ranged from 4 to 5 for RA and 5 to 6 for OA. Median RAPID3 scores ranged from 9.7 to 11.8 for RA and 11.7 to 16.8 for OA. Median fatigue scores ranged from 3.5 to 5 for RA and 3.3 to 5 for OA. Median physician global scores ranged from 0 to 4 for RA and1 to 5 for OA.
Conclusions Among treated patients, levels of patient pain, physical function, patient and physician global estimates, RAPID3, and fatigue reported by patients with OA are as great as or greater than for patients with RA. While the findings likely reflect in part better treatments for RA, they suggest that the severity of OA may be underestimated. Better information concerning OA may lead to improved clinical management and resource allocation for OA.
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Disclosure of Interest None declared