Background There are disease-specific activity measures for almost each rheumatic disease. Disease-specific questionnaires may be optimal for clinical trials and other research studies, but it is not feasible to have patients complete different self-report questionnaires in busy clinical settings. A single questionnaire regarding to disease activity for all rheumatic diseases may present advantages to introduce quantitative measurement into routine care. Recently, routine assessment of patient index data 3 (RAPID3) which is based on 3 multi-dimensional health assessment questionnaire (MDHAQ) components, including patient function, pain, and patient global assessment, is speculated to be a candidate index for most of the rheumatic diseases.

Objectives To evaluate correlation of RAPID3 with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and AS Disease Activity Score (ASDAS).

Methods This single-center, cross-sectional study was performed in a rheumatology department at a tertiary-care hospital in Turkey between May 2011 and September 2013. We included 341 consecutive AS patients who met the modified New York classification criteria. All patients completed BASDAI, and MDHAQ at each visit, and their physicians completed physician global assessment. ASDAS scores were calculated using defined formulas. Proposed RAPID3 severity categories were compared to BASDAI and ASDAS categories. Spearman's rho correlation test and kappa statistics were used to analyze statistical significance.

Results The median age of AS patients was 34.0 (21.0-69.0) years and the median disease duration 10.0 (2.0-35.0) years; 273 patients (80.1%) were male. Median scores for RAPID3, BASDAI, ASDAS-CRP, and ASDAS-ESR, were 13.0 (0.0-27.3), 4.7 (0.0-9.7), 3.0 (0.4-5.8), 2.5 (0.5-6.3), respectively. RAPID3 was strongly correlated with BASDAI, and ASDAS-ESR (r=0.842, r=0.815; p<0.001, respectively). Among the 209 patients with high disease activity according to BASDAI, 83.3% had high or moderate severity according to RAPID3. The kappa statistic for agreement of RAPID3 with BASDAI was 0.693 (p<0.001). Among the 133 patients with moderate, high, and very high disease activity on ASDAS-CRP, 91.7% had high or moderate severity according to RAPID3. The kappa statistic for agreement of RAPID3 with ASDAS-CRP was 0.548 (p<0.001).

Conclusions RAPID3 is as informative as BASDAI and ASDAS in our cohort of AS patients. We therefore suggest that RAPID3 may be used to assess, monitor, and document patient status quantitatively in AS patients, as part of routine care.

Disclosure of Interest : None declared

DOI 10.1136/annrheumdis-2014-eular.1940