Flare in spondyloarthritis: Thresholds of disease activity variations

Defining and managing flares in axial spondyloarthritis

PURPOSE OF REVIEW

Flares correspond to fluctuations in disease activity or symptoms. They should be avoided in chronic inflammatory diseases. In axial spondyloarthritis (axSpA), work is ongoing to better conceptualise and treat flares. This review highlights recent data on the definition and management of flares in axSpA.

RECENT FINDINGS

Many definitions of flares have been used in clinical trials, limiting the interpretation and comparison of studies. The expert group Assessment of SpondyloArthritis International Society (ASAS) developed a data-driven definition of flares/disease worsening: an increase in Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP) of at least 0.9 points, for use in axSpA clinical trials. Flares are more challenging to define in clinical practice because of their multifaceted nature. Qualitative studies have shown that flares from the patient's perspective are related not only to disease activity, but also to fatigue, mood, sleep and general well-being. The management of axSpA relies on a treat-to-target (T2T) strategy and aims at reaching clinical remission while monitoring closely disease activity to prevent and shorten flares.

SUMMARY

The concept of flares has been clarified, and definitions have been developed for use in trials. The T2T approach aims at minimising flares in axSpA. The early recognition of flares and their severity may lead to better management.

Correspondence between patient-reported flare and disease activity score variation in axial spondyloarthritis: a 12-months web-based study

OBJECTIVE

The aims of this study were to determine thresholds of variations of BASDAI and pain associated with patient-reported outbreak or resolution of flare and to test performance of ASAS preliminary definitions of flare.

METHODS

SpA patients registered on the Spondy+ platform were invited to fill BASDAI and global pain on numeric rating scales every week during one year and to tell if they experienced flare since last week. Performance of BASDAI and pain variations (ΔBASDAI and Δpain) to detect occurrence and resolution of flare was determined with receiver operator characteristic (ROC) curves.

RESULTS

Ninety-one of the 99 axSpA patients included reported at least one episode of flare. Area under the ROC curve was significantly higher for ΔBASDAI than for Δpain to predict outbreak of flare (0.81 vs. 0.77, p<0.05) without statiscally significant difference to predict flare resolution (0.78 vs. 0.80). Best sensitivity/specificity compromise was obtained for ΔBASDAI of 0.2 and 0.4 points to predict flare outbreak or resolution, respectively. All the ASAS definitions obtained a specificity higher than 95% whereas sensitivity was lower than 40%.

CONCLUSION

ΔBASDAI appeared as a suitable variable to monitor occurrence and resolution of patient-reported flare in axSpA.

Patient-reported Flares in Ankylosing Spondylitis: A Cross-sectional Analysis of 234 Patients

OBJECTIVE

Ankylosing spondylitis (AS) is characterized by periodic flares. The objective of this study was to assess the frequency of patient-reported flares and their related factors.

METHODS

This cross-sectional study analyzed the 2004 data of a Canadian cohort. Participants had AS according to the modified New York criteria. Current flare status ("Are you experiencing a current flare"?), number of flares over the past 3 months, their average duration, the Bath Ankylosing Spondylitis Disease Activity and Functional Index (BASDAI and BASFI, respectively), and the AS Quality of Life questionnaire were assessed by self-report. Univariate and multivariate regressions analyzed the factors associated with current flare.

RESULTS

Among 234 analyzed patients, 169 (73.5%) were men, mean age was 45.5 (± 11.8) years, mean disease duration of 21.7 (± 11.7) years, and mean BASDAI and BASFI (0-10) of 4.4 (± 2.3) and 3.4 (± 2.6), respectively; 18 (7.7%) received antitumor necrosis factor (anti-TNF). Overall, 175 patients (74.8%) reported flares and 117 (50%) were currently in flare. Patients reporting flares had a median of 3 flares in 3 months, with a median duration of 2 weeks. Overall, the 234 patients spent a median of 25% of their time in flare. In multivariate analyses, current flare was significantly associated with higher BASDAI (OR 2.01, p = 0.01), worse quality of life (OR 1.37, p = 0.004), shorter AS duration (OR 1.19, p = 0.04), and less anti-TNF (OR 7.14, p = 0.03).

CONCLUSION

In this population, before the wide use of biologics, flares were frequent and long. As expected, flare was associated with higher disease activity, suggesting the validity of the concept of patient-reported flares.

Predictors of Loss of Remission and Disease Flares in Patients with Axial Spondyloarthritis Receiving Antitumor Necrosis Factor Treatment: A Retrospective Study

Objective.

The aim of this study was to evaluate rate and predictive factors of loss of remission and disease flare in patients with axial spondyloarthritis (axSpA) receiving antitumor necrosis factor (anti-TNF) treatment.

Methods.

In this retrospective multicenter study, patients with axSpA, according to the Assessment of Spondyloarthritis international Society (ASAS) criteria, treated with adalimumab, etanercept, or infliximab with a minimum followup of 12 months and satisfying the ASAS partial remission criteria and/or Ankylosing Spondylitis Disease Activity Score (ASDAS) inactive disease were studied. Disease flare was defined as a Bath Ankylosing Spondylitis Disease Activity Index score > 4.5 or ASDAS score > 2.5 on at least 1 occasion.

Results.

One hundred seventy-four patients with axSpA were studied. After a median [interquartile range (IQR)] followup of 4 years (2–6), 37 patients (21.2%) experienced a loss of remission and 28 (16.1% of the whole study group) a disease flare. Median (IQR) duration of remission in patients who lost this status was 1 year (0.625–2). Higher median erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values, continuous nonsteroidal antiinflammatory drug (NSAID) use, and an ASDAS-CRP ≥ 0.8 during the remission period were significantly associated with both loss of remission and disease flare. At the multivariate analysis, continuous NSAID intake (OR 4.05, 95% CI 1.4–11.74, p = 0.010) and ESR > 15 (OR 2.90, 95% CI 1.23–6.82, p = 0.015) were the only factors predictive of disease reactivation.

Conclusion.

In this study, loss of remission and disease flares occurred, respectively, in about 21% and 16% of the patients with axSpA who achieved a state of remission while receiving anti-TNF therapy. Residual disease activity was associated with disease reactivation.

Preliminary definitions of 'flare' in axial spondyloarthritis, based on pain, BASDAI and ASDAS-CRP: an ASAS initiative

INTRODUCTION

Flares may be used as outcomes in axial spondyloarthritis (axSpA) trials or observational studies. The objective was to develop a definition for 'flare' (or worsening) in axSpA, based on validated composite indices, to be used in the context of clinical trial design.

METHODS

(1) Systematic literature review of definitions of 'flare' in published randomised controlled trials in axSpA. (2) Vignette exercise: 140 scenarios were constructed for a typical patient with axSpA seen at two consecutive visits. Each scenario included a change in one of the following outcomes: pain, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), BASDAI plus C-reactive protein (CRP) or Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP. Each Assessment of Spondyloarthritis (ASAS) expert determined if every scenario from a random sample of 46 scenarios was considered a flare (yes/no). Receiver-operating characteristic (ROC) analyses were applied to derive optimal cut-off values. (3) ASAS consensus was reached.

RESULTS

(1) The literature review yielded 38 studies using some definition of 'flare', with 27 different definitions indicating important heterogeneity. The most frequent definitions were based on BASDAI changes or pain changes. (2) 121 ASAS experts completed 4999 flare assessments. The areas under the ROC curves were high (range: 0.88-0.89). Preliminary cut-offs for pain (N=3), BASDAI (N=5) and ASDAS-CRP (N=4) were chosen, with a range of sensitivity 0.60-0.99 and range of specificity 0.40-0.94 against the expert's opinions.

CONCLUSIONS

This data-driven ASAS consensus process has led to 12 preliminary draft definitions of 'flare' in axSpA, based on widely used indices. These preliminary definitions will need validation in real patient data.

Patient-physician discordance in global assessment in early spondyloarthritis and its change over time: the DESIR cohort

Objective

To assess patient-physician discordance in global assessment of disease activity in early axial spondyloarthritis (axSpA) over time and determinants of discordance.

Methods

DESIR (Devenir des Spondyloarthropathies Indifférenciées Récentes) is a French, multicentre, longitudinal cohort of patients with early inflammatory back pain suggestive of axSpA. Patient global assessment (PGA) and physician global assessment (PhGA) were rated with a 0–10 numerical rating scale, every 6 months during 2 years then at 3 years. Discordance was defined by the absolute difference |PGA–PhGA|≥3 (range 0–10) and was analysed at each visit. Determinants of (PGA−PhGA) were assessed at the visit level by a generalised linear mixed model.

Results

A total of 702 patients were analysed at baseline (401 with complete data over 3 years): mean age 33.8±8.6 years, 379 (54.0%) female, mean symptom duration 18.1±10.5 months. Mean PGA values were always higher than mean PhGA values with a mean absolute difference of 1.8 points. At baseline, 202 (28.8%) patients had discordance mainly by PGA>PhGA; over 3 years the frequency of discordance was stable (range 25.5–28.8%). Discordance was not stable at the patient level, 118 (29.4%) patients were discordant once and 88 (22.0%) twice, and only 92 (22.9%) more than twice. Determinants of (PGA−PhGA) were spine pain (β=0.24, p<0.001) and fatigue (β=0.13, p<0.001).

Conclusions

Discordance concerned a quarter of patients with early axSpA. Over 3 years of follow-up, discordance did not decrease (no ‘reference shift’). Discordance was not a stable trait, indicating discordance is not a patient characteristic.