Evaluation of disease activity in rheumatoid arthritis by Routine Assessment of Patient Index Data 3 (RAPID3) and its correlation to Disease Activity Score 28 (DAS28) and Clinical Disease Activity Index (CDAI): an Indian experience

[Implementation, of multidisciplinary consultations for patients with inflammatory arthritis and treated with subcutaneous biologic DMARDs: Assessment at one year and outlook]

INTRODUCTION

Biologics (bDMARDs) have revolutionized the prognosis of patients with inflammatory arthritis, but are not without serious side effects. The patient must be able to identify them, acquire self-care abilities or skills and adhere to their treatment. Multidisciplinary consultations, including a pharmaceutical consultation could improve the care of these patients. The pharmaceutical presence make it easier to switch to a biosimilar with etended patient support thanks to the community-hospital network. The return on investment is possible thanks to the more frequent use of biosimilars and the pricing of this type of consultation by the "Forfait de Prestation Intermédiaire".

METHODOLOGY

Eligible patients are patients with rheumatoid arthritis or spondyloarthritis, treated with subcutaneous bDMARDs. The criteria assessed were patient's knowledge of their biotherapy using the Biosecure score, their medication adherence using the CQR-5, the total of switch to biosimilars perform and the financial statement of the consultations. An assessment of the actions deployed for the community-hospital network.

RESULTS

Two hundred and ninety-five patients (47.4%) benefited multidisciplinary consultation. The mean score of the Biosecure score was 69.6/100 (moderate knowledge) and 261 patients (88.5%) were highly adherent. 57 patients (73%) accepted the switch to biosimilar. 197 pharmacy were contacted, all of witch for patients who receive the switch. Overall patient's satisfaction was 26.9/28.

CONCLUSION

Multidisciplinary consultations with involvement of the pharmacist should optimized patient care and the management of outpatients treated with bDMARDs. Patients have already expressed their satisfaction with this course of care and the return on investment is positive.

Impact of Perceived Stress During the SARS-CoV-2 Pandemic on Rheumatoid Arthritis Patients' Disease Activity: An Online Survey

INTRODUCTION/OBJECTIVES

Psychological stress worsens rheumatoid arthritis (RA) disease activity, and the COVID-19 pandemic has increased stress/anxiety in rheumatic patients. The purpose of this study was to determine if stress during the COVID-19 pandemic specifically impacts RA disease activity as reported by the patient.

METHOD

This was a cross-sectional COVID-19 RA survey study. University of California, Los Angeles rheumatology clinic patients were emailed a link to a survey in July and November 2020. The 30-question survey pertained to COVID-19-related stress, RA disease activity, and demographics. For the survey responders, anti-cyclic citrullinated antibody, rheumatoid factor, and age were extracted from the electronic health record. Analyses were performed to examine the association between the 4-item Perceived Stress Scale (PSS-4) and other COVID-19-related stress measures with the Routine Assessment of Patient Index Data 3 (RAPID3).

RESULTS

A total of 1138/5037 subjects completed the emailed survey (22.6% response rate). When examining responses across RAPID3 categories (near remission, low, moderate, and high disease severity), there were significant increases in PSS-4 and other stress variables. Multiple linear regression models showed that PSS-4, financial stress, age, seropositivity, disease duration, and Black race were independently associated with worsened RAPID3 scores, when controlling for other confounding factors.

CONCLUSIONS

This study suggests that stress overall negatively impacts RAPID3, and Black RA patients had a higher RAPID3 scores during the COVID-19 pandemic. Despite colossal efforts to combat the pandemic, RA patients currently suffer from stress/anxiety, and methods to mitigate these psychological effects are needed.

Routine Assessment of Patient Index Data 3 (RAPID3) in Patients with Rheumatoid Arthritis Treated with Long-Term Upadacitinib Therapy in Five Randomized Controlled Trials

Introduction

The Routine Assessment of Patient Index Data 3 (RAPID3) is a patient-reported outcome tool recommended for the assessment of disease activity in patients with rheumatoid arthritis (RA) in clinical practice. This analysis evaluated the long-term effect of upadacitinib vs. comparators on RAPID3 scores in patients with RA in the phase 3 SELECT clinical trial program.

Methods

This post hoc analysis included data from five randomized controlled trials (RCTs) in patients receiving upadacitinib 15 mg or 30 mg once daily (QD) as monotherapy or in combination with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). The proportions of patients reporting RAPID3 remission (scores ≤ 3) were assessed at week 60. Correlations between absolute scores for RAPID3 and Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), and 28-joint Disease Activity Score with C-reactive protein (DAS28[CRP]) at week 60 were assessed using Spearman correlation coefficients.

Results

A total of 3117 patients were included from the SELECT-NEXT, -BEYOND, -MONOTHERAPY, -COMPARE, and -EARLY trials. By week 60, 32–52% of methotrexate-naïve and csDMARD inadequate responder (IR) patients treated with either upadacitinib 15 mg QD or upadacitinib 30 mg QD reported RAPID3 scores consistent with remission. The proportions were slightly lower in the biologic DMARD-IR SELECT-BEYOND population (19–28%). RAPID3 scores highly correlated (Spearman correlation values ≥ 0.58) with CDAI, SDAI, and DAS28(CRP) scores through week 60 (all p < 0.001).

Conclusions

Upadacitinib, as monotherapy or in combination with csDMARDs, was associated with patient-reported remission assessed by RAPID3 over 60 weeks across the SELECT RCTs in patients with RA.

Trial registration

SELECT-BEYOND (NCT02706847); SELECT-NEXT (NCT02675426); SELECT-MONOTHERAPY (NCT02706951); SELECT-EARLY (NCT02706873); SELECT-COMPARE (NCT02629159).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-022-00483-4.

Rheumatoid arthritis (RA) is a disease that causes inflammation of the joints. Doctors have several ways of assessing how bad a patient’s disease is, and these often use a combination of signs and symptoms to develop a ‘score’. One method is called RAPID3, which is a score based on an overall assessment of the disease by the patient, the level of pain, and the amount of physical disability. An advantage of RAPID3 is that it is quick and easy to use, and since it uses only patient-reported symptoms, it can be measured easily via telemedicine, without the need for an in-person consultation. In this study, we decided to look into the effect of upadacitinib, a drug used for the treatment of RA, on RAPID3 score in patients with RA. We also investigated whether RAPID3 correlates with other ways of measuring RA severity, including scores that use physician-measured factors such as number of affected joints, as this can help show whether RAPID3 is a valid and useful tool. We found that upadacitinib led to long-term improvements in RAPID3 score, and that results were the same in different studies and patient groups, including patients who had not responded well to other treatments. We also found that RAPID3 correlated well with other measures, i.e., improvements in RAPID3 happened in parallel with improvements in other scores. Overall, these results suggest that RAPID3 can be a useful tool in patients with RA.

The RAPID3 questionnaire as a screening tool to reduce the number of outpatient clinic visits: a retrospective cohort study

Background

Treat-to-target strategies require frequent on-site evaluations of disease activity in patients with rheumatoid arthritis (RA), burdening patients and caregivers. However, this frequency may not be required in patients in a stable low disease activity state. The Routine Assessment of Patient Index Data 3 (RAPID3) is a reliable tool to detect such states in groups but has not been tested to reduce the frequency of on-site evaluations in individual patient care. In Reade, an outpatient rheumatology clinic, patients can complete the questionnaire online prior to consultation, and the results are directly fed into the electronic patient record. Focusing on low disease activity, we retrospectively studied the test characteristics of RAPID3 and its agreement with the DAS28 in our database of routine patient care.

Objective

To assess the test characteristics and agreement between de DAS28 and the RAPID3 in patients with RA, with a focus on the low disease activity categories.

Methods

We performed a retrospective database study with available clinical data collected as part of usual care from the electronic medical record at Reade Amsterdam. The dataset comprised RAPID3 assessments followed by a DAS28 within 2 weeks, obtained between June 2014 and March 2021. We dichotomized the disease activity categories for both the RAPID3 and DAS28 into low (remission and low disease activity) and high (moderate and high disease activity). With cutoff values of 2.0 for RAPID3 and 3.2 for DAS28, we calculated test characteristics and agreement (Cohen’s kappa).

Results

A total of 5009 combined RAPID3 and DAS28 measurements were done at Reade in 1681 unique RA patients. The mean age was 60 years, and 76% of patients were female with a median disease duration of 4 years. Agreement was considered fair (kappa = 0.26). In total, 1426 (28%) of the RAPID3 measurements were classified as low and could be potentially targeted to skip their consultations. The sensitivity to detect low disease activity was 0.39, specificity was 0.93, and the positive predictive value was 0.92.

Conclusion

We showed that when the RAPID3 classifies a patient into low disease activity state, the accuracy is 92%. Of all consultations, 28% could possibly be postponed following the screening with RAPID3.

Patient Reported Outcome Measures for Rheumatoid Arthritis Disease Activity: a systematic review following COSMIN guidelines

BACKGROUND

The current standard of care in rheumatoid arthritis (RA) requires regular assessment of disease activity (DA). All standard RA DA measurement instruments require joint counts to be undertaken by a healthcare professional with/without a blood test. Few healthcare providers have the capacity to assess patients as frequently as stipulated by guidelines. Patient Reported Outcome Measures (PROMs) could be an efficient and informative way to assess RA DA, which is highlighted by the SARS-COV-2 pandemic, as most consultations are remote rather than face-to-face. We aimed to assess all PROMs for RA DA against the internationally recognised COSMIN guidelines to provide evidence-based recommendations to select the most suitable PROMs.

METHODS

Review registered on PROSPERO as CRD42020176176. The search strategy was based on a previous similar systematic review and expanded to include all articles up to January 2019. All identified articles were rated by two independent assessors following the COSMIN guidelines.

RESULTS

668 abstracts were identified, with 10 articles included. A further 21 were identified from a previous review. Ten PROMs were identified. There was insufficient evidence to place any of the identified PROMs into recommendation for use category A due to lack of evidence for content validity, as stipulated by the COSMIN guidelines.

CONCLUSION

Lack of evidence of content validity limits suitable PROM selection, therefore none can be recommended for use. It is acknowledged that all included PROMs were developed before the COSMIN guidelines were published. Future research on PROMs for RA DA must provide evidence of content validity.

Dairy Consumption: Does It Make an Impact on Self-Reported Disease Activity of Inflammatory Arthritis?

Background

As researchers and the public become more cognizant of the impacts of diet and nutrition on health, continued research is needed to provide evidence to support dietary claims. At present, there exists mixed reporting on the effects of dairy consumption and disease activity of inflammatory arthritis (IA).

Objective

This study attempts to advance current research on the relationship between dairy consumption and self-reported disease activity in patients with IA and to investigate whether dietary modifications can be helpful as a conservative, cost-effective, and accessible supplement to established treatments.

Methods

Participants completed a modified diet history questionnaire (DHQ), which assessed dairy consumption over the past year, and a Routine Assessment of Patient Index Data 3 (RAPID3) questionnaire, which assessed a participants’ self-reported inflammatory disease activity. DHQ and RAPID3 were analyzed using a Pearson product-moment partial correlation to assess variables’ relationships. Participants completed the questionnaire in the setting of a rheumatology clinic. Two hundred and four participants were recruited for this study. All of the participants were at least 18 years of age, capable of giving informed consent, and were formally diagnosed with either rheumatoid arthritis or psoriatic arthritis by a board-certified rheumatologist. 

Results

The results from the questionnaires found that dairy consumption does not contribute to self-reported IA disease activity. While 11 of the 16 DHQ variables maintained a positive correlation with the overall RAPID3 scores, none of these possessed statistical significance. Only when controlling for age and sex did the study find two statistically significant variable correlations between the quantity of milk consumed as a beverage (r=0.147, n=193, p=0.043) and milk added to cereal (r=0.170, n=189, p=0.019) with the RAPID3 scores.

Conclusion

In summation, the study found no notable correlation between dairy consumption and patients’ self-reported IA disease activity.

The association between serum levels of growth differentiation factor-15 and rheumatoid arthritis activity

BACKGROUND

Macrophages play a crucial role in the pathogenesis of rheumatoid arthritis (RA). Growth differentiation factor-15 (GDF-15) acts as an autocrine regulator of macrophage activation.

OBJECTIVE

The aim of this study was to assess serum level of GDF-15 as a potential biomarker for detecting RA activity.

METHOD

A total of 100 female RA patients and 55 age and weight matched healthy control females were enroled. The serum level of GDF-15 was measured using enzyme-linked immunosorbent assay.

RESULTS

Serum levels of GDF-15 in RA patients with high, moderate, low and no disease activity were 989.0 ± 161.9, 505.6 ± 220.5, 349.2 ± 155.9 and 349.0 ± 144.0 pg/mL, respectively. GDF-15 with a cut-off value higher than 705 pg/mL was indicative of high RA activity with sensitivity of 96% and specificity of 92%.

CONCLUSION

GDF-15 serum levels may be used as a biomarker to predict high RA disease activity.

Routine Assessment of Patient Index Data 3 (RAPID3) alone is insufficient to monitor disease activity in rheumatoid arthritis in clinical practice

Objective

To test the longitudinal association between patient-reported outcome, Routine Assessment of Patient Index Data 3 (RAPID3) and the Disease Activity Score in 28 joints that includes the erythrocyte sedimentation rate (DAS28-ESR) in routine-care patients with rheumatoid arthritis (RA).

Methods

Patients with RA treated with disease-modifying antirheumatic drugs were included in this prospective observational cohort. The longitudinal association between RAPID3 (0-10) and DAS28-ESR and its individual components (swollen joint count (SJC), erythrocyte sedimentation rate (ESR) (mm/hour), tender joint count (TJC) and patient global assessment (PGA)) was tested using generalised estimating equations in patients with more than two consecutive visits with data on RAPID3 and DAS28-ESR. Interactions between RAPID3 and gender, pain, PGA and age at baseline were tested, and if significant (p<0.20) and clinically relevant, models were fit in the corresponding strata.

Results

In total, 330 patients were included (mean follow-up 10.7 (SD 9.7) months, female gender 67.9%). The longitudinal association between RAPID3 and DAS28-ESR was weak (β=0.29 (95% CI 0.24 to 0.35), n=207), meaning that one unit increase in RAPID3 corresponded to a 0.29 unit increase in Disease Activity Score in 28 joints (DAS28). RAPID3 was most strongly associated with subjective (TJC: β=0.89 (95% CI 0.61 to 1.17); PGA: β=0.94 (95% CI 0.84 to 1.04)) and not with objective components of DAS28 (SJC: β=0.29 (95% CI 0.17 to 0.41), n=172). The association between RAPID3 and ESR was poor but modified by gender, being only significant in men (β=0.37 (95% CI 0.08 to 0.67)).

Conclusions

These data suggest that RAPID3 does not sufficiently capture changes in objective inflammatory signs. Monitoring by RAPID3 alone is therefore insufficient to follow disease activity in patients wth RA in clinical practice.

Measurement of Disease Activity in Ecuadorian Patients with Rheumatoid Arthritis: Does RAPID3 Correlate with Traditional Indexes?

Objective

The aim of this study is to demonstrate if routine assessment of patient index data 3 has a correlation with disease's activity as much as disease activity score 28, clinical disease activity index, and simplified disease activity index in Ecuadorian patients with rheumatoid arthritis seen in Unidad de Enfermedades Reumáticas y Autoinmunes [UNERA] from December 2016 to December 2017.

Methods

This is a retrospective study in 200 patients that fulfill the American College of Rheumatology 2010 criteria for diagnosis of rheumatoid arthritis. The patients were evaluated from December 2016 to December 2017. Descriptive analyses were carried out, also Pearson correlation was used, and, to give a better clinical significance, a chi-square test was conducted. Whenever assumptions of chi-square test were violated, a Fisher's exact test was reported.

Results

RAPID3 correlated best with DAS28 (r.83, p < 0.001), followed by CDAI (r.80, p < 0.001) and then SDAI (r.77, p < 0.001).

Conclusion

RAPID3 is a questionnaire that only takes 10 seconds to calculate and correlates in a significant way with traditional clinical measures that require more time to perform, saving time in busy health facilities.

Performance of routine assessment of patient index data 3 (RAPID3) in monitoring disease activity of Chinese rheumatoid arthritis patients

AIM

To explore the performance of routine assessment of patient index data 3 (RAPID3) in reflecting disease activity in Chinese rheumatoid arthritis (RA) patients.

METHOD

The clinical data of 189 consecutive RA patients, including RAPID3 questionnaire, Disease Activity Score based on 28-joint count (DAS28), clinical disease activity index (CDAI) and simplified disease activity index (SDAI), and ultrasonography of hand and wrist joints were collected. The consistency between RAPID3 and DAS28, CDAI, SDAI in RA patients with different disease activities was performed by Spearman's correlations, kappa and/or weighted kappa coefficients.

RESULT

RAPID3 score was significantly associated with DAS28 and erythrocyte sedimentation rate (ESR), DAS28 with C-reactive protein (CRP), CDAI, SDAI (r = 0.797, 0.786, 0.784, and 0.760 respectively, P < 0.001 for all). RAPID3 was also significantly correlated with tender joint count, swollen joint count, ESR and CRP. The agreement of RAPID3 with DAS28 scoring systems was better in patients with moderate/high disease activity than those in remission/low disease activity. Ultrasonographic subclinical synovitis was presented in 42.3%-48.6% of patients in remission/low disease activity defined by various scoring criteria including RAPID3 with no significant difference observed (P = 0.22, >0.05).

CONCLUSION

RAPID3 showed good correlation with DAS28 scoring systems, especially in patients with moderate/high disease activity. RAPID3 is a reliable and convenient tool to monitor disease activity.

Correlation between rapid-3, DAS28, CDAI and SDAI as a measure of disease activity in a cohort of Colombian patients with rheumatoid arthritis

The objective of this study is to correlate the patient-driven tool Routine Assessment of Patient Index Data 3 (RAPID-3) with other common tools used in daily practice to measure disease activity in rheumatoid arthritis (RA).One hundred nineteen RA patients according to 1987 American College of Rheumatology criteria who consecutively attended a RA outpatient clinic between August and December 2015 were evaluated. Data was stored in an electronic form that included demographic information, comorbidities, concomitant medication, and laboratory results. The disease activity was determined by tender and swollen joint count, pain and disease activity visual analog scales (VAS), disease activity score 28 (DAS28), Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), and multidimensional health assessment questionnaire (MDHAQ). Correlations between RAPID-3 and other disease activity tools were assessed. Mean age was 61 ± 13.8 years with a median disease duration of 14 years (IQR 5-21), 77% were females. Median scores were MDHAQ 0.5 (IQR 0.1-1.2), DAS 28 3.8 (IQR 2.7-5.1), and RAPID-3 12.3 (IQR 6-19). A strong correlation was obtained between RAPID-3 and DAS 28 (r 0.719, p < 0.001), CDAI (r 0.752, p < 0.001), and SDAI (r 0.758, p < 0.001). RAPID-3 had a high correlation with tools regularly used for disease activity assessment of RA patients in daily practice. The ease of its application favors routine use as it does not require laboratory results and joint counts.

Systematic review of patient-reported outcome measures (PROMs) for assessing disease activity in rheumatoid arthritis

Patient assessment of disease activity in rheumatoid arthritis (RA) may be useful in clinical practice, offering a patient-friendly, location independent, and a time-efficient and cost-efficient means of monitoring the disease. The objective of this study was to identify patient-reported outcome measures (PROMs) to assess disease activity in RA and to evaluate the measurement properties of these measures. Systematic literature searches were performed in the PubMed and EMBASE databases to identify articles reporting on clinimetric development or evaluation of PROM-based instruments to monitor disease activity in patients with RA. 2 reviewers independently selected articles for review and assessed their methodological quality based on the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) recommendations. A total of 424 abstracts were retrieved for review. Of these abstracts, 56 were selected for reviewing the full article and 34 articles, presenting 17 different PROMs, were finally included. Identified were: Rheumatoid Arthritis Disease Activity Index (RADAI), RADAI-5, Patient-based Disease Activity Score (PDAS) I & II, Patient-derived Disease Activity Score with 28-joint counts (Pt-DAS28), Patient-derived Simplified Disease Activity Index (Pt-SDAI), Global Arthritis Score (GAS), Patient Activity Score (PAS) I & II, Routine Assessment of Patient Index Data (RAPID) 2–5, Patient Reported Outcome-index (PRO-index) continuous (C) & majority (M), Patient Reported Outcome CLinical ARthritis Activity (PRO-CLARA). The quality of reports varied from poor to good. Typically 5 out of 10 clinimetric domains were covered in the validations of the different instruments. The quality and extent of clinimetric validation varied among PROMs of RA disease activity. The Pt-DAS28, RADAI, RADAI-5 and RAPID 3 had the strongest and most extensive validation. The measurement properties least reported and in need of more evidence were: reliability, measurement error, cross-cultural validity and interpretability of measures.

Evaluating patient reported outcomes in routine practice of patients with rheumatoid arthritis treated with biological disease modifying anti rheumatic drugs (b-DMARDs)

Objectives

In this study the concordance between the Routine Assessment of Patient Index Data 3 (RAPID3) and the Disease Activity Score 28-joint count (DAS28) was investigated in a clinical routine outpatient setting.

Patients and methods

A sample of 150 adult patients with stable RA treated with biological DMARDs (bDMARDs) was asked to complete the RAPID3 (digital or on paper) just before their outpatient routine visit during which DAS28 assessment took place. The RAPID3 correlation with and the agreement in four DAS28 categories was studied using Spearman’s rank order and Cohen’s observed kappa statistics respectively. The positive (PPV) and negative (NPV) predictive values were calculated to test whether RAPID3 could make distinction in active disease (DAS28 >3.2) or not.

Results

A moderate correlation (ρ 0.576) and a poor kappa value of 0.13 were found in the whole study population. Patients reported a higher disease severity than was measured by DAS28. The PPV of RAPID3 for active disease by DAS28 was 0.59 (95 % CI 0.50–0.68) and the NPV was 0.91 (95 % CI 0.75–0.98) with a sensitivity and specificity of 96 and 40 % respectively.

Discussion

While RAPID3 correlates to some extent with DAS28 at the group level, agreement between RAPID3 and DAS28 at the individual patient level is to poor to rely on RAPID3 results in monitoring patients with RA. RAPID3 tends to over-report disease activity as assessed by DAS28.

Is the state of health of rheumatoid arthritis patients receiving adequate treatment, predictable? - Results of a survey

Background

A survey was conducted to evaluate whether a steady improvement in the quality of life of Rheumatoid Arthritis (RA) patients as frequently reported in clinical studies, does actually occur. The focus of this study laid on the personal perception of RA patients. How do patients who have been treated along accepted guidelines see the state of their health and their joint pain at different points in time?

Methods

RA patients were asked to complete a questionnaire and return it to an opinion research centre. The questionnaire, which was developed by the authors, was divided into the areas: demography, symptom description and medical care, as well as the illness in a personal context. Three telephone interviews followed in monthly intervals when the patients´ feelings about their illness, their every-day coping mechanisms and their social lives were rated. Intra-subject correlation and the level of agreement among patients when assessed at three different points within a two month period, was determined.

Results

127 patients replied to the questionnaire. RA exerts a significant impact on a patient’s daily life. Average ratings of current state of health and joint pain (answered on a 5-part scale extending from 1 (very good) to 5 (very bad)) range between 2.6 and 2.9 all three times. However, intra-subject correlation between the different assessment times, is in general quite modest. Concerning the question: “How is your join pain today?” only 14 of 127 participants express identical ratings all three times , while in one third of the participants, a difference of two digits on the 5-part scale, at least twice had to be noticed. Intra-class correlation coefficients between answers at different points are often much smaller than 0.5. Results were similar in all subgroups analysed (men vs. women; patients receiving biologics vs. those not receiving biologics; disease duration ≤3 years vs. 4 to 10 years vs. ≥11 years).

Conclusion

On an individual level personal assessments of health, well-being and joint pain are nevertheless unsteady even within the timeframe of two months. This is why, even now, RA patients still cannot plan their lives as non-affected people can.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0567-5) contains supplementary material, which is available to authorized users.

Performance of Routine Assessment of Patient Index Data 3 (RAPID3) for assessment of rheumatoid arthritis in clinical practice: differential agreement of RAPID3 according to disease activity categories

To evaluate the performance of Routine Assessment of Patient Index Data 3 (RAPID3) with the disease activity score 28 (DAS28) and the clinical/simplified disease activity index (CDAI/SDAI) in a Korean population with rheumatoid arthritis (RA). Four hundred patients with RA were consecutively enrolled. All patients completed disease activity indices such as RAPID3, DAS28, SDAI, and CDAI. The kappa and/or weighted coefficients were used to assess agreement between RAPID3 and other disease activity indices. ANOVA, Mantel-Haenszel chi-square test, and Spearman's partial correlation analysis were used for analyses. RAPID3 scores were significantly correlated with DAS28 (r = 0.62), SDAI (r = 0.74), and CDAI (r = 0.75; p < 0.0001 for all indices) and other activity measures including swollen/tender joint counts, erythrocyte sediment rate, and C-reactive protein. The weighted kappa coefficients of RAPID3 with DAS28, SDAI, and CDAI among the four disease activity categories were 0.33, 0.34, and 0.33, respectively. Kappa coefficients for RAPID3 in two disease activity categories increased more than four categories (κ = 0.40-0.42) indicating fair agreement. More than 86 % of patients with high-to-moderate disease activity in DAS28, CDAI, and SDAI had high-to-moderate disease activity using RAPID3 criteria. However, approximately 50 % of patients with remission-to-low disease activity in DAS28, CDAI, and SDAI showed remission-to-low disease activity in RAPID3. This study confirms RAPID3 as an informative disease activity index with equivalent values in DAS28, CDAI, and SDAI. RAPID3 reveals differential agreement in patients with lower disease activity.