RAPID3 and ACR/EULAR Provisional Definitions as Predictors of Radiographic Outcome in a Rheumatoid Arthritis Clinical Trial with Tocilizumab

Arthritis Care Res 2016; Accepted article. DOI 10.1002/acr.23008.

The findings reported represent the first validation of RAPID3 (Routine Assessment of Patient Index Data 3) remission ± SJC ≤1 as an alternative to the established SDAI or Boolean remission definitions, which can be time consuming and costly to measure. RAPID3 is a pooled index of the patient-reported measures: function, pain and Patient Global estimate of status.Data were analysed from the TociLIzumab Safety and THE Prevention of Structural Joint Damage (LITHE) study, a 2-year double-blind Phase 3 randomised controlled trial in MTX-IR patients with moderate to severe RA. Year 1 measures (RAPID3 remission or RAPID3 low disease activity, both ± a single SJC; SDAI criteria and/or Boolean criteria) and their association with Year 2 radiographic and functional outcomes were examined.At the end of Year 2, sufficient data were available for 690 patients. Achieving Year 1 measures was statistically significantly associated with higher odds of achieving good radiographic plus functional outcomes at Year 2. The predictability of RAPID 3 ± joint count was similar to that of SDAI and Boolean criteria, with joint count not substantially affecting its predictability.RAPID3 measurement requires patient input only, can be completed quickly, and could help engage patients in their own care. Importantly, by increasing the number of physicians who measure and use disease activity (treat to target), patient outcomes may be improved.