Re-examining remission definitions in rheumatoid arthritis: considering the 28-Joint Disease Activity Score, C-reactive protein level and patient global assessment

RheuMetric Quantitative 0 to 10 Physician Estimates of Inflammation, Damage, and Distress in Rheumatoid Arthritis: Validation Against Reference Measures

OBJECTIVE

To analyze a RheuMetric checklist, which includes four feasible physician 0 to 10 scores for DOCGL, inflammation (DOCINF), damage (DOCDAM), and distress (DOCSTR) for criterion and discriminant validity against standard reference measures.

METHODS

A prospective, cross-sectional assessment was performed at one routine care visit at Liverpool Hospital, Sydney, Australia. Rheumatologists recorded DOCGL, DOCINF, DOCDAM, DOCSTR, and 28 joint counts for swelling (SJC), tenderness (TJC), and limited motion/deformity (DJC). Patients completed a multidimensional health assessment questionnaire (MDHAQ), which includes routine assessment of patient index data (RAPID3), fibromyalgia assessment screening tool (FAST4), and MDHAQ depression screen (MDS2). Laboratory tests and radiographic scores were recorded. RheuMetric estimates of inflammation, damage, and distress were compared with reference and other measures using correlations and linear regressions.

RESULTS

In 173 patients with RA, variation in RheuMetric DOCINF was explained significantly by SJC and inversely by disease duration; variation in DOCDAM was explained significantly by DJC, radiographic scores, and physical function; and variation in DOCSTR was explained significantly by fibromyalgia and depression.

CONCLUSION

RheuMetric DOCINF, DOCDAM, and DOCSTR estimates were correlated significantly and specifically with reference measures of inflammation, damage, and distress, documenting criterion and discriminant validity.

Patient global assessment is elevated by up to 5 of 10 units in patients with inflammatory arthritis who screen positive for fibromyalgia (by FAST4) and/or depression (by MDS2) on a single MDHAQ

BACKGROUND

Patient global assessment (PATGL) is a component of rheumatoid arthritis (RA) and spondyloarthritis (SpA) activity indices, reflecting inflammation in selected clinical trial patients. In routine care, PATGL often may be elevated independently of inflammatory activity by fibromyalgia (FM) and/or depression, leading to complexities in interpretation. A feasible method to screen for FM and/or depression could help to clarify interpretation of high PATGL and index scores, including explanation of apparent limited responses to anti-inflammatory therapies.

PATIENTS AND METHODS

Patients with RA or SpA in routine care in Barcelona, Chicago, and Sydney complete a 2-page multidimensional health assessment questionnaire (MDHAQ) in 5-10 min. The MDHAQ includes PATGL and three indices, RAPID3 (routine assessment of patient index data) to assess clinical status, FAST4 (0-4 fibromyalgia assessment screening tool) and MDS2 (0-2 MDHAQ depression screen). PATGL was compared for each diagnosis at each site and pooled data in FAST4 positive (+) vs negative (-) and/or MDS2+ vs MDS2- patients using medians and median regressions.

RESULTS

Median PATGL was 5.0 in 393 RA and 175 SpA patients; 2.0-3.0 in 305 (58.9%) FAST4-,MDS2- patients, 5.5-6.0 in 71 (13.7%) FAST4-,MDS2+ patients, 7.0-7.5 in 50 (9.7%) FAST4+,MDS2- patients, and 7.0-8.0 in 92 (17.8%) FAST4+,MDS2+ patients. Positive FAST4 and/or MDS2 screens were seen in 41% of patients. Results were similar in RA and SpA at 3 settings on 3 continents.

CONCLUSION

Median 0-10 PATGL varied from 2-3/10 to 5.5-8/10, according to negative vs positive screening for FM and/or depression on a single MDHAQ for busy clinical settings.

A systematic comparison of different composite measures (DAS 28, CDAI, SDAI, and Boolean approach) for determining treatment effects on low disease activity and remission in rheumatoid arthritis

BACKGROUND

Some composite measures for determining the treatment effects of disease-modifying antirheumatic drugs on remission and low disease activity (LDA) in rheumatoid arthritis (RA) may produce misleading results if they include an acute phase reactant (APR). To inform the choice of appropriate measure, we performed a systematic comparison of treatment effects using different composite measures.

METHODS

We used data generated for a systematic review of biologics in RA conducted by the Institute for Quality and Efficiency in Health Care and data from systematic reviews of newer biologics and Janus kinase (JAK) inhibitors provided by sponsors. The studies included had been conducted up to 2020 and investigated comparisons of biologics with placebo and head-to-head comparisons of biologics. Treatment effects on LDA and remission in studies investigating biologics or JAK inhibitors in RA were compared among 4 composite measures: the disease activity score 28 (DAS 28), the simplified disease activity index (SDAI), the Boolean approach (remission only), and the clinical disease activity index (CDAI)-only the latter does not include an APR.

RESULTS

49 placebo-controlled studies included 9 different biologics; 48 studies (16,233 patients) investigated LDA and 49 (16,338 patients) investigated remission. 11 active-controlled studies (5996 patients) investigated both LDA and remission and included 5 different head-to-head comparisons of biologics and 5 different comparisons (6 studies) of biologics with JAK inhibitors. Statistically significantly larger treatment effects were found for biologics or JAK inhibitors versus placebo or active control in 16% of pairwise comparisons of composite measures (27 of 168). Most of these larger effects were observed for composite measures with an APR, i.e. the DAS 28 (19 comparisons) followed by the SDAI (n = 7). Larger effects were most frequently detected in favour of interleukin (IL)-6 inhibitors and to a lesser extent for JAK inhibitors versus treatments with different modes of action.

CONCLUSIONS

The use of the DAS 28 and SDAI in clinical studies may generate results favouring certain treatments based on their mode of action (e.g. IL-6 inhibitors versus other biologics). To enable unbiased comparative effectiveness research, a composite measure without an APR (i.e. the CDAI) should thus be the measure of choice.

Inflammatory correlates of the Patient Global Assessment of Disease Activity vary in relation to disease duration and autoantibody status in patients with rheumatoid arthritis

OBJECTIVE

To investigate the associations between the Patient Global Assessment (PGA) and measures of disease activity in patients with rheumatoid arthritis (RA) in relation to disease duration and autoantibody status.

METHODS

1412 patients from three independent cohorts were studied: a prospective cohort of 810 patients with early RA followed up for 24 months; a cross-sectional cohort of 210 patients with established RA in low disease activity; a cross-sectional cohort of 401 patients with established RA in moderate-to-high disease activity. Correlations of the PGA were analysed by Pearson's coefficients and multivariable linear regression at baseline and at months 6, 12 and 24 in the overall populations and after stratification for autoantibody subgroup and remission status (Boolean remission, PGA near remission and non-remission).

RESULTS

In patients with early RA in non-remission, swollen joints correlated independently with the PGA; the correlation became progressively weaker but persisted at all time points in autoantibody-positive patients (adjusted r=0.30-0.12) but lost significance after month 12 in autoantibody-negative patients. Swollen joints independently correlated with the PGA also in near remission until month 12 (adjusted r=0.18-0.16) in autoantibody-positive patients. No independent correlations of inflammatory variables were instead found in patients with established RA irrespective of disease activity and autoantibody status.

CONCLUSIONS

In the early phases of RA, particularly in autoantibody-positive patients, inflammatory variables directly correlate with the PGA across different disease activity states. The optimal cut-off values of the PGA capable of identifying absence of disease should be better explored in relation to disease duration and autoantibody status.