Background Rheumatoid arthritis impact of disease (RAID) is a well validated patient reported outcome (PRO) in patients with Rheumatoid Arthritis (RA) [1]. RAID score involves the active participation of patients and can be easily calculated at the comfort of home with minimal training and assistance or while the patient is waiting to see the doctor in the outpatient department. It is helpful in giving an idea of the overall well-being of the patient and takes into account sleep and depression which are the unmet needs in RA treatment. However, the effectiveness of RAID as a patient reported outcome and the optimal RAID score which can be used as a target for treat-to-target approach has not been studied in the Indian population.

Objectives To determine if the RAID score can be used as a PRO target along with a clinician reported disease activity score for managing patients with RA under a treat-to-target approach. To establish an acceptable cut-off for the RAID score which can be used as a target in patients with RA and validate it against disease activity indices.

Methods We prospectively enrolled patients with RA diagnosed using ACR/EULAR 2010 criteria in our tertiary care institute, at Jodhpur, India from March 2021 to May 2022 and followed them over 6 months after their written informed consent and Ethics Committee approval (AIIMS/IEC/2021/3370). DAS28, patient assessment of global disease activity (PtGA), Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), RAID score and modified Boolean indices (2) were calculated at enrolment and 6 months. Binary logistic regression analysis was used to determine if RAID could reliably predict DAS28 <3.2 and Boolean remission indices at enrolment and 6 months. DAS28 <3.2, CDAI ≤10 and SDAI ≤11 were considered as the target as per EULAR recommendations, with remission and low disease activity as acceptable goals to achieve while treating patients with RA.

Results We included 156 patients with a mean age of 47.0±12.3 years, 86.5% were females. Among them, 23.4% patients had DAS28 <3.2, 11.7% had SDAI ≤11, 13.6% had CDAI ≤10 while only 0.6% were in Boolean and Boolean2.0 remission. At 6 months, 110 patients were followed up and among them, 78.6% had achieved DAS28 <3.2, 66.0% had achieved SDAI ≤11, 68.9% had achieved CDAI ≤10 while only 1.9% had achieved remission according to Boolean remission criteria. However, Boolean2.0 criteria showed that 20.9% were in remission. RAID score could reliably and independently predict DAS28, SDAI, CDAI, PtGA and Boolean2.0 criteria.

We constructed multiple Receiver Operating Characteristic (ROC) curves to determine the optimal cut-off of RAID for defining low disease activity and remission using SDAI, CDAI, DAS28 and Boolean2.0 remission criteria (Figure 1). We noted that the RAID score of 2.32 had 85.7% sensitivity and 76.1% specificity in predicting SDAI ≤11 and 87.5% sensitivity and 74.3% specificity in predicting CDAI ≤10. Further, RAID score of 2.32 had a sensitivity of 86.4% and specificity of 72.5% in predicting DAS28 <3.2 and a sensitivity of 55.9% and specificity of 81.2% in predicting remission as per Boolean2.0 criteria.

Conclusion RAID score can be used as a reliable and validated PRO in patients with RA. We also propose a cut-off of a composite RAID score of 2.32 as an additional target to achieve while treating patients with RA in the Indian population.

References [1]Gossec L, Paternotte S, Aanerud GJ, Balanescu A, Boumpas DT, Carmona L, et al. Finalisation and validation of the rheumatoid arthritis impact of disease score, a patient-derived composite measure of impact of rheumatoid arthritis: a EULAR initiative. Ann Rheum Dis. 2011 Jun;70(6):935–42.

[2]Studenic P, Aletaha D, de Wit M, Stamm TA, Alasti F, Lacaille D, et al. American College of Rheumatology/EULAR Remission Criteria for Rheumatoid Arthritis: 2022 Revision. Arthritis Rheumatol. 2023;75(1):15–22.

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Acknowledgements: NIL.

Disclosure of Interests None Declared.