Indian Journal of Rheumatology

: 2017  |  Volume : 12  |  Issue : 4  |  Page : 209--213

A comparison of 3 rheumatoid arthritis disease activity indices in routine clinical practice

Amit Kumar Das, Rathindra Nath Sarkar, Chandan Kumar Das, Ritasman Baisya, Urmimala Bhattacharjee, Pallab Biswas, Akashdip Bhattacharya 
 Department of Medicine, Medical College, Kolkata, West Bengal, India

Correspondence Address:
Rathindra Nath Sarkar
GD - 43, Sector 3, Salt Lake City, Kolkata - 700 106, West Bengal


Objective: The objective of this study was to appraise the correlation and agreement of RAPID 3 with DAS 28 and CDAI in terms of measuring disease activity/severity and for monitoring response to treatment at 2 and 4 month follow up. Methods: 105 adult literate persons having rheumatoid arthritis according to the 2010 ACR EULAR revised criteria were included. They were evaluated for disease activity by DAS 28, CDAI, and RAPID 3 scores. Response to treatment at 2 month and 4 month follow up was measured by these scores. Achievement of treatment target was defined as conversion from high/moderate disease activity at initial visit to low activity/remission at follow up visit. Result: The mean DAS 28 (0-10), CDAI (0-76) , RAPID 3 (0-30) were 4.73 , 16.72, 10.72 respectively. There was substantial agreement between DAS 28 and RAPID 3 severity categories (kappa = 0.959, P < 0.0001) and also between CDAI and RAPID 3. Conclusion: In a busy clinical setting, our study has shown usefulness of RAPID3 compared to the two most commonly used indices to assess disease activity in RA, both in terms of measuring quantitative disease activity as well as monitoring of treatment response at follow up visits.

How to cite this article:
Das AK, Sarkar RN, Das CK, Baisya R, Bhattacharjee U, Biswas P, Bhattacharya A. A comparison of 3 rheumatoid arthritis disease activity indices in routine clinical practice.Indian J Rheumatol 2017;12:209-213

How to cite this URL:
Das AK, Sarkar RN, Das CK, Baisya R, Bhattacharjee U, Biswas P, Bhattacharya A. A comparison of 3 rheumatoid arthritis disease activity indices in routine clinical practice. Indian J Rheumatol [serial online] 2017 [cited 2020 Jul 2 ];12:209-213
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Full Text


For clinical practice, experts generally agree that Rheumatoid Arthritis (RA) related inflammation should be controlled as soon as possible and as completely as possible, and that control should be maintained for as long as possible, consistent with patient safety.[1] With the goal of treatment to attain and sustain low disease activity or even remission, the management of RA should clearly include systematic and regular quantitative evaluation of rheumatoid inflammation.[2] These principles are now widely known as “tight control” in the treatment of RA.[3],[4] Disease Activity Score (DAS) is a mathematical score devised by van der Heijde et al. in the 1990s [5],[6],[7] to quantify disease activity or monitoring treatment with disease-modifying antirheumatic drugs using 28-Joint Count after several modifications.[4],[8],[9],[10],[11],[12] A formal quantitative joint count is often not performed at most busy outpatient visits,[13] so DAS 28 and Clinical Disease Activity Index (CDAI)[14] are not routinely used. Besides, DAS 28 has low specificity for remission and low disease activity.[15]

Routine Assessment of Patient Index Data 3 (RAPID 3) is an index without formal joint counts, which is used to assess and monitor patients with RA and can be completed in [16],[17] RAPID 3 is included by the American College of Rheumatology (ACR) among the indices used to measure RA disease activity [18],[19] which can be calculated in 5–10 s on a Multidimensional Health Assessment Questionnaire (MDHAQ). An index that requires Study design

This observational study was conducted at our institute from July 2014 to August 2015. One-hundred and five adult patients who were classified as RA as per 2010 criteria were included.[20] Patients attended scheduled follow-ups at 2 month (1st follow-up) and 4 month (2nd follow-up) from the enrollment visit. All the patients were studied on the basis of demographic evaluation, clinical evaluation, questionnaire in Bengali/English to be completed by patients themselves, 28-Joint Count for tender and swollen joints, and estimation of erythrocyte sedimentation rate by Westergren method.

The MDHAQ [21],[22] includes the three self-report RA core dataset scores for physical function, pain, and patient global estimate (PtGA) (formula and format downloaded from http://mdhaq. org/public/Questionnaires.asps). Each is scored on a scale of 0–10. The investigator calculated a RAPID 3 score from the MDHAQ before or while seeing the patient and entered the score on the MDHAQ. DAS 28 (scoring formula and format downloaded from and CDAI score ( were calculated. All the 105 patients getting different forms of treatment were followed up at 2 months and 4 months and the same method of data collection was followed for each patient at each visit. All patients were evaluated for disease activity by DAS 28, CDAI, and RAPID 3 scores at 1st and 2nd follow-up visit. Achievement of treatment target (i.e., conversion from high/moderate disease activity at initial visit to low activity/remission at follow-up visit) measured by RAPID 3 at 2- and 4-month follow-up was compared with change in disease activity measured by DAS 28 and CDAI at the same time intervals. A validated Bengali translation of the RAPID 3 questionnaire was used for patients not familiar in English.

Statistical analysis

Statistical analysis was done using SPSS 20.0 software SPSS 20.0 software (IBM, Armonk, NY, United States of America). Spearman's rank-order correlation coefficients were computed to compare RAPID 3 with DAS 28 and CDAI at all the three visits. 4-month follow-up was measured in all the 105 patients Level of agreement between the three scoring methods in measuring achievement of treatment target was analyzed using Kappa statistics.

Ethical approval

The study was approved by the ethics committee of the institute. Informed written consent was obtained from all patients prior to their enrollment in this study.


The mean age of patients was 42.46 years, with 80 (76.2%) females and rest were males [Table 1]. On initial visit, mean DAS 28 (0–10 scale), CDAI (0–76 scale), and RAPID 3 (0–30 scale) scores were 4.73 ± 1.44, 16.72 ± 12.77, and 10.72 ± 6.11, respectively. On the 1st follow-up visit, the corresponding scores were 4.05 ± 1.06, 10.46 ± 6.90, and 7.42 ± 3.76, respectively. On the 2nd follow-up visit, the corresponding scores were 3.55 ± 1.05, 7.78 ± 6.69, and 5.98 ± 3.32, respectively.{Table 1}

On initial visit, all the three scores significantly correlated with each other, the maximum correlation was between DAS 28 and CDAI (ρ =0.980, P < 0.001), in the 2nd visit; there was also a significant correlation with highest between DAS 28 and CDAI (ρ =0.947, P < 0.001). In the final visit, all the three scores were correlated significantly. At the initial visit RAPID 3 had substantial agreement with both DAS 28 and CDAI [Table 2] and [Table 3]. Same degree of substantial agreement was also found the 1st and 2nd follow-up visits.{Table 2}{Table 3}

Additional analyses were performed for each index in two groups, high/moderate compared with low/remission. There was a high agreement (percentage) between RAPID 3/DAS 28/CDAI for moderate-to-high activity/severity and remission/near remission to low activity/severity [Table 4].{Table 4}

Achievement of treatment target was defined as conversion from high/moderate disease activity at initial visit to low activity/remission at follow-up visit.[1],[2],[3],[4],[23] Achievement of treatment target was comparable between DAS 28 and RAPID 3 scores – kappa value of agreement was 0.861 at 2 months and 1.00 at 4 months (P < 0.0001) [Table 5].{Table 5}

Achievement of treatment target between CDAI and RAPID 3 scores showed complete agreement – kappa value of agreement in the 2nd and 4th months was 1.00 for both (P < 0.0001) [Table 6].{Table 6}


RAPID 3 scores were significantly correlated with DAS 28 and CDAI scores in this study, similar to the results seen in previous other studies by Pincus et al[22],[23] (P = 0.995 for RAPID 3 vs. DAS 28 and P = 0.943 for RAPID 3 vs. CDAI, both highly statistically significant [P < 0.001]). Comparisons of RAPID 3 scores with DAS 28 and CDAI scores in 285 patients, in a study by Pincus et al., indicated Spearman's rank-order correlation coefficients for DAS 28 with RAPID 3 of 0.66 and for CDAI with RAPID 3 of 0.74, all highly statistically significant (P = 0.001).[23]

Overall, 97%–100% of the patients identified as having high or moderate activity according to the DAS 28 and CDAI scores, the level at which rheumatologists might strongly consider a change in therapy, had high or moderate activity according to the RAPID 3. Similarly, 96%–100% of patients had low activity/remission according to the RAPID 3 compared with the DAS 28 and CDAI scores. There was a substantial agreement between DAS 28 and RAPID 3 severity categories (kappa = 0.959, P < 0.0001) and also between CDAI and RAPID 3 severity categories (kappa = 0.931, P < 0.0001). Although most patients met criteria for moderate or high activity according to DAS 28 or CDAI, they also met criteria for moderate or high RAPID 3 severity. A few patients had discrepant values. Perhaps, these findings may be explained in part by sensitivity of this patient questionnaires (RAPID 3) to long-term joint damage (i.e., functional impairment of involved joints) as well as inflammatory activity. In additional analysis, it was found that RAPID 3 score field had almost identical results in agreement with DAS 28 and CDAI scores to monitor achievement of treatment target at 2- and 4-month follow-up period.

Hence, it can be concluded that RAPID 3, performs as well as the two most commonly used indices to assess disease activity in RA – DAS 28 and CDAI – both in terms of measuring quantitative disease activity as well as monitoring of treatment response at follow-up.

It must be emphasized that no index including RAPID 3 can act as a substitute for a careful history and joint examination in assessing the patients with RA. In addition, based on this study, it can not be suggested that a formal tender and swollen 28-Joint Count is not required to monitor the patients of RA, but RAPID 3 appears preferable to no quantitative clinical data at all (other than laboratory tests), as usually seen in contemporary rheumatology visits. Quantitative data in the form of RAPID 3 scores can help in guiding the treatment decisions and improve patient outcomes, particularly in busy clinical settings where DAS28 and CDAI take longer time for calculation of disease activity than RAPID 3 score.

All RA disease activity measures and indices are surrogates, and limitations are seen for the joint count and DAS 28[24] as well as for patient questionnaires and RAPID 3.[25] One limitation of using RAPID 3 to assess disease activity is that it can only be used in literate patients. Nonetheless, physical function as reported by a patient on a questionnaire, and not a laboratory test or radiograph, provides the most significant clinical prognostic indicator of most severe 5–10 year outcomes of RA (other than radiographic damage), including work disability, cost, and mortality.[26]

This study has several limitations. First, this study was conducted in only one center, and it would be desirable to have larger, multiple centric studies. Second, this study followed up patients only for a 4-month period, and longitudinal data from clinical settings would appear desirable to study the potential value of RAPID 3 in helping to guide therapy further. However, rigorous longitudinal observations concerning RAPID 3 are available from clinical trials.

In conclusion we have found that RAPID 3 is comparatively easily scored than DAS 28 or CDAI. in addition, RAPID 3 appears to have usefulness in assessing and monitoring and documenting patient's status quantitatively in busy clinical settings which is essential to improve care and enhance documentation.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Wolfe F, Cush JJ, O'Dell JR, Kavanaugh A, Kremer JM, Lane NE, et al. Consensus recommendations for the assessment and treatment of rheumatoid arthritis. J Rheumatol 2001;28:1423-30.
2Fransen J, Stucki G, van Riel P. The merits of monitoring: Should we follow all our rheumatoid arthritis patients in daily practice? Rheumatology (Oxford) 2002;41:601-4.
3Kiely PD, Brown AK, Edwards CJ, O'Reilly DT, Ostör AJ, Quinn M, et al. Contemporary treatment principles for early rheumatoid arthritis: A consensus statement. Rheumatology (Oxford) 2009;48:765-72.
4Grigor C, Capell H, Stirling A, McMahon AD, Lock P, Vallance R, et al. Effect of a treatment strategy of tight control for rheumatoid arthritis (the TICORA study): A single-blind randomised controlled trial. Lancet 2004;364:263-9.
5van der Heijde DM, van 't Hof MA, van Riel PL, Theunisse LA, Lubberts EW, van Leeuwen MA, et al. Judging disease activity in clinical practice in rheumatoid arthritis:First step in the development of a disease activity score. Ann Rheum Dis 1990;49:916-20.
6van der Heijde DM, van 't Hof M, van Riel PL, van de Putte LB. Development of a disease activity score based on judgment in clinical practice by rheumatologists. J Rheumatol 1993;20:579-81.
7Prevoo ML, van 't Hof MA, Kuper HH, van Leeuwen MA, van de Putte LB, van Riel PL. Modified disease activity scores that include twenty-eight-joint counts. Development and validation in a prospective longitudinal study of patients with rheumatoid arthritis. Arthritis Rheum 1995;38:44-8.
8Möttönen T, Hannonen P, Leirisalo-Repo M, Nissilä M, Kautiainen H, Korpela M, et al. Comparison of combination therapy with single-drug therapy in early rheumatoid arthritis: A randomised trial. FIN-RACo trial group. Lancet 1999;353:1568-73.
9Puolakka K, Kautiainen H, Möttönen T, Hannonen P, Korpela M, Hakala M, et al. Early suppression of disease activity is essential for maintenance of work capacity in patients with recent-onset rheumatoid arthritis: Five-year experience from the FIN-RACo trial. Arthritis Rheum 2005;52:36-41.
10Goekoop-Ruiterman YP, de Vries-Bouwstra JK, Allaart CF, van Zeben D, Kerstens PJ, Hazes JM, et al. Clinical and radiographic outcomes of four different treatment strategies in patients with early rheumatoid arthritis (the BeSt study): A randomized, controlled trial. Arthritis Rheum 2005;52:3381-90.
11Goekoop-Ruiterman YP, de Vries-Bouwstra JK, Allaart CF, van Zeben D, Kerstens PJ, Hazes JM, et al. Comparison of treatment strategies in early rheumatoid arthritis: A randomized trial. Ann Intern Med 2007;146:406-15.
12Verstappen SM, Jacobs JW, van der Veen MJ, Heurkens AH, Schenk Y, ter Borg EJ, et al. Intensive treatment with methotrexate in early rheumatoid arthritis: Aiming for remission. Computer Assisted Management in Early Rheumatoid Arthritis (CAMERA, an open-label strategy trial). Ann Rheum Dis 2007;66:1443-9.
13Pincus T, Segurado OG. Most visits of most patients with rheumatoid arthritis to most rheumatologists do not include a formal quantitative joint count. Ann Rheum Dis 2006;65:820-2.
14Aletaha D, Smolen J. The Simplified Disease Activity Index (SDAI) and the Clinical Disease Activity Index (CDAI): A review of their usefulness and validity in rheumatoid arthritis. Clin Exp Rheumatol 2005;23 5 Suppl 39:S100-8.
15Salaffi F, Cimmino MA, Leardini G, Gasparini S, Grassi W. Disease activity assessment of rheumatoid arthritis in daily practice: Validity, internal consistency, reliability and congruency of the Disease Activity Score including 28 joints (DAS28) compared with the Clinical Disease Activity Index (CDAI). Clin Exp Rheumatol 2009;27:552-9.
16Yazici Y, Bergman M, Pincus T. Time to score quantitative rheumatoid arthritis measures: 28-Joint Count, Disease Activity Score, Health Assessment Questionnaire (HAQ), Multidimensional HAQ (MDHAQ), and Routine Assessment of Patient Index Data (RAPID) scores. J Rheumatol 2008;35:603-9.
17Pincus T, Swearingen CJ, Bergman MJ, Colglazier CL, Kaell AT, Kunath AM, et al. RAPID 3 (routine Assessment of Patient Index Data) on an MDHAQ (Multidimensional Health Assessment Questionnaire); agreement with DAS 28 (Disease Activity Score) and CDAI (Clinical Disease Activity Index) activity categories, scored in five versus more than ninety seconds. Arthritis Care Res 2010;62:181-9.
18Saag KG, Teng GG, Patkar NM, Anuntiyo J, Finney C, Curtis JR, et al. American College of Rheumatology 2008 recommendations for the use of nonbiologic and biologic disease-modifying antirheumatic drugs in rheumatoid arthritis. Arthritis Rheum 2008;59:762-84.
19Anderson J, Caplan L, Yazdany J, Robbins ML, Neogi T, Michaud K, et al. Rheumatoid arthritis disease activity measures: American College of Rheumatology recommendations for use in clinical practice. Arthritis Care Res (Hoboken) 2012;64:640-7.
20Aletaha D, Neogi T, Silman AJ, Funovits J, Felson DT, Bingham CO 3rd, et al. 2010 rheumatoid arthritis classification criteria: An American College of Rheumatology/European League Against Rheumatism collaborative initiative. Ann Rheum Dis 2010;69:1580-8.
21Pincus T, Swearingen C, Wolfe F. Toward a multidimensional Health Assessment Questionnaire (MDHAQ): Assessment of advanced activities of daily living and psychological status in the patient-friendly health assessment questionnaire format. Arthritis Rheum 1999;42:2220-30.
22Pincus T, Sokka T, Kautiainen H. Further development of a physical function scale on a MDHAQ [corrected] for standard care of patients with rheumatic diseases. J Rheumatol 2005;32:1432-9.
23Pincus T, Swearingen CJ, Bergman M, Yazici Y. RAPID3 (Routine Assessment of Patient Index Data 3), a rheumatoid arthritis index without formal joint counts for routine care: Proposed severity categories compared to disease activity score and clinical disease activity index categories. J Rheumatol 2008;35:2136-47.
24Pincus T. The DAS is the most specific measure, but a patient questionnaire is the most informative measure to assess rheumatoid arthritis. J Rheumatol 2006;33:834-7.
25Mäkinen H, Hannonen P. How to assess patients with rheumatoid arthritis and concomitant fibromyalgia? J Rheumatol 2009;36:9-11.
26Pincus T, Wolfe F. Patient questionnaires for clinical research and improved standard patient care: Is it better to have 80% of the information in 100% of patients or 100% of the information in 5% of patients? J Rheumatol 2005;32:575-7.