Measuring quality of life of patients with axial spondyloarthritis for economic evaluation.

OBJECTIVES: To estimate the relationship between EQ5D (three levels, UK version) and the Ankylosing Spondylitis Disease Activity Score (ASDAS) for use in the economic evaluation of health technologies for people with axial spondyloarthritis (axSpA). To compare against the relationship with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). METHODS: An electronic, prospective, Portuguese, nationwide, rheumatic disease register (Reuma.pt) provided data on 1140 patients (5483 observations) with a confirmed diagnosis of axSpA. We estimated models of EQ5D as a function of ASDAS, alone or in combination with measures of functional impairment, using bespoke mixture models which reflect the complex distributional features of EQ5D. The SPondyloArthritis Caught Early cohort provided data from 344 patients (1405 observations) in four European countries and was used for validation. A previously published model of BASDAI/Bath Ankylosing Spondylitis Functional Index (BASFI) was also used to generate predicted EQ5D scores and model performance compared. RESULTS: A non-linear relationship exists between EQ5D from ASDAS. The final model included ASDAS, ASDAS squared, age and age squared and demonstrated close fit in both datasets except where data were sparse for patients with very high levels of disease activity (ASDAS >4). This finding held in the validation dataset. Models that included BASFI improved model fit. The ASDAS based models fit the data marginally less well than models using BASDAI. CONCLUSIONS: Mapping models linking ASDAS to EQ5D allow results from clinical studies to be used in economic evaluation of health technologies with confidence. There is some loss of information compared with BASDAI but this has only a marginal impact.

Impact of the combined presence of erosions and ACPA on rheumatoid arthritis disease activity over time: results from the METEOR registry.

Objective: To investigate associations between baseline presence of erosions and/or anti-citrullinated protein antibodies (ACPA) on functional ability, disease activity and treatment survival over time. Methods: Real life data from newly diagnosed rheumatoid arthritis patients were identified in the international METEOR registry. Patients were grouped according to presence/absence of ACPA and/or erosions at baseline. Associations between the presence of ACPA and/or erosions (four groups) with the change of Disease Activity Score (DAS) and Health Assessment Questionnaire (HAQ) over time were assessed using linear mixed models during maximum 6 or maximum 12 months from baseline. Treatment survival was assessed using multiple failure-times Cox regression. Results: Data were included from 701 ACPA‒/erosions‒, 334 ACPA‒/erosions+, 1585 ACPA+/erosions‒ and 1993 ACPA+/erosions+ patients. We found statistically significant differences in DAS and HAQ change over time between the four groups, both after maximum follow-up durations of 6 and of 12 months, but after stratification differences proved small and not clinically meaningful. Patients in the ACPA‒/erosions‒ group were less likely to switch treatment compared with the ACPA+/erosions‒ reference group (p<0.001). The other two ACPA/erosions groups did not differ from the reference group. Conclusions: In this analysis of worldwide real life data, we found statistically significant, but clinically irrelevant differences in treatment response to initial disease modifying anti-rheumatic drug therapies as measured by DAS and HAQ in ACPA‒/erosions‒, ACPA‒/erosions+, ACPA+/erosions‒ and ACPA+/erosions+ rheumatoid arthritis patients. However, after maximum follow-up durations of 6 and 12 months all groups had a similar response to initial treatment, but with a lower likelihood to switch treatment for ACPA‒/erosions‒ patients during the first year of follow-up.

An Internet-based technique for the identification of persons with symptoms of inflammatory polyarthritis of less than 12 weeks.

Identifying persons with early rheumatoid arthritis (RA) is a major challenge. The role of the Internet in making decisions about seeking care has not been studied. We developed a method for early diagnosis and referral using the Arthritis Foundation's website. A person with less than 3 months of joint pain symptom who has not yet sought medical attention was screened. Prescreened persons are linked to a self-scoring questionnaire and get a "likelihood" of RA statement. If "likely," the person is offered a free evaluation and biomarker testing performed by Quest Diagnostics. The system available only to Massachusetts's residents yielded a small steady flow of screen-positive individuals. Over 21 months, 43,244 persons took the Arthritis Foundation website prescreening questionnaire; 196 were from Massachusetts and 60 took the self-scoring algorithm. Of the 48 who screened positive, 29 set up an appointment for a free evaluation, but six never came in. Twenty-four subjects were evaluated and diagnosed independently by three rheumatologists. One met the 1987 American College of Rheumatology (ACR) criteria for RA and two met the 2010 ACR/EULAR RA criteria. The 24 examined individuals were contacted at a minimum of 1 year and asked to redo the case-finding questionnaire and asked about their health resource utilization during the interval. Seventeen of the 24 subjects responded, and 10 had seen a health professional. Three of the 17 had a diagnosis of RA; all were on at least methotrexate. Internet case finding was useful in identifying new potential RA cases. The system's performance characteristics are theoretically limited only by the number of study sites available. However, the major barrier may be that seeing a health professional is not a priority for many individuals with early symptoms.