Efficacy assessed in follow-ups of clinical trials: methodological conundrum

Increasingly, we see papers describing the long-term follow-up results of randomised clinical trials. Sometimes, like the article by Rantalaiho and colleagues in the previous issue of Arthritis Research & Therapy, the follow-up extends to more than 10 years. It is not uncommon that authors of such articles describe their results as a comparison of the original treatment groups in the original randomised clinical trial. Methodologically, such a comparison is fallible for several reasons. In this editorial, two important sources of bias that may jeopardise the results of such follow-up studies are discussed: confounding by indication and confounding by trial completion

The validity of a rheumatoid arthritis medical records-based index of severity compared with the DAS28

Outcome measures play an extremely important role in clinical trials and observational research. Outcome measures for rheumatoid arthritis cover a whole array of domains, ranging from measures describing the inflammatory process to measures describing the ultimate consequences of long-term disease, such as joint damage, physical function and quality of life. There is a scientific need to be able to quantify what is called the 'severity of rheumatoid arthritis', so that patients with rheumatoid arthritis can be clustered according to their propensity to develop an unfavourable outcome. It is a challenge to find an appropriate measure for severity. One attempt has been the development of the Rheumatoid Arthritis Medical Record-Based Index of Severity. This commentary elaborates on how such a measure of severity should be validated to determine whether it is appropriate for practical use

The earlier, the better or the worse? Towards accurate management of patients with arthralgia at risk for RA

The favourable long-term results of early treatment in patients with classified rheumatoid arthritis have resulted in an increasing interest in the diseases phases preceding clinical arthritis. The hypothesis to test is that an intervention in these early phases may better prevent or reduce disease persistence than an intervention when arthritis has become clinically manifest. While several placebo-controlled trials are still ongoing, to date there is no firm evidence that this hypothesis truly holds. Therefore, it is important to reflect on the current status of arthralgia preceding clinical arthritis. Inherent to every new field of research, attitudes are conflicting, with opinions propagating innovation (based on the fear of undertreatment) on the one hand, and critical sounds pleading for more restraint (fear of overtreatment) on the other hand. In this Viewpoint, we will examine these divergent opinions, relate them to a preferred ultimate scenario and provide considerations for future studies and daily practice

A review through the lens of causal inference

Funding Information: Competing interests AS: Consulting/speaking fees from MSD, UCB, Novartis. SR: Research grant from MSD; Consultancy/speaking fees from AbbVie, Eli Lilly, MSD, Novartis, UCB, Sanofi. DvdH: Consulting fees AbbVie, Amgen, Astellas, AstraZeneca, Bayer, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma Director of Imaging Rheumatology bv. RL: Consulting fees from AbbVie, BMS, Celgene, Eli-Lilly, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Roche, UCB and is Director of Rheumatology Consultancy bv Publisher Copyright: ©Axial spondyloarthritis (axSpA) is a chronic rheumatic disease characterised by inflammation predominantly involving the spine and the sacroiliac joints. In some patients, axial inflammation leads to irreversible structural damage that in the spine is usually quantified by the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Available therapeutic options include biological disease-modifying antirheumatic drugs (bDMARDs), which have been proven effective in suppressing inflammation in several randomised controlled trials (RCT), the gold standard for evaluating causal treatment effects. RCTs are, however, unfeasible for testing structural effects in axSpA mainly due to the low sensitivity to change of the mSASSS. The available literature therefore mainly includes observational research, which poses serious challenges to the determination of causality. Here, we review the studies testing the effect of bDMARDs on spinal radiographic progression, making use of the principles of causal inference. By exploring the assumptions of causality under counterfactual reasoning (exchangeability, positivity and consistency), we distinguish between studies that likely have reported confounded treatment effects and studies that, on the basis of their design, have more likely reported causal treatment effects. We conclude that bDMARDs might, indirectly, interfere with spinal radiographic progression in axSpA by their effect on inflammation. Innovations in imaging are expected, so that placebo-controlled trials can in the future become a reality. In the meantime, causal inference analysis using observational data may contribute to a better understanding of whether disease modification is possible in axSpA.publishersversionpublishe

The performance of different classification criteria sets for spondyloarthritis in the worldwide ASAS-COMOSPA study

Background: In this study, we sought to compare the performance of spondyloarthritis (SpA) classification criteria sets in an international SpA cohort with patients included from five continents around the world. Methods: Data from the (ASAS) COMOrbidities in SPondyloArthritis (ASAS-COMOSPA) study were used. ASAS-COMOSPA is a multinational, cross-sectional study with consecutive patients diagnosed with SpA by rheumatologists worldwide. Patients were classified according to the European Spondyloarthropathy Study Group (ESSG), modified European Spondyloarthropathy Study Group (mESSG), Amor, modified Amor, Assessment of SpondyloArthritis international Society (ASAS) axial Spondyloarthritis (axSpA), ASAS peripheral spondyloarthritis (pSpA) and ClASsification criteria for Psoriatic Arthritis (CASPAR) criteria. Overlap between the classification criteria sets was assessed for patients with and without back pain. Furthermore, patients fulfilling different arms of the ASAS axSpA criteria (imaging arm, clinical arm, both arms) were compared on the presence of SpA features. Results: A total of 3942 patients (5 continents, 26 countries) were included. The mean age was 43.6 years, 65.0% were male, 56.2% were human leucocyte antigen B27-positive and 64.4% had radiographic sacroiliitis (based on modified New York criteria). Of the patients, 85.5% were classified by the ASAS SpA criteria (87.7% ASAS axSpA, 12.3% ASAS pSpA). Fulfilment of the Amor, ESSG and CASPAR criteria was present in 83.3%, 88.4% and 21.6% of patients, respectively. Of the patients with back pain (n = 3227), most were classified by all three of Amor, ESSG and ASAS axSpA criteria (71.4%). Patients fulfilling the imaging arm and the clinical arm of the ASAS axSpA criteria had similar presentations of SpA features. In patients without back pain, overlap between classification criteria sets was seen, although to a lesser extent. Conclusions: Most patients with a clinical diagnosis of axial SpA in the worldwide ASAS-COMOSPA study fulfil several classification criteria sets, and a substantial overlap between different criteria sets is seen, which suggests a high level of credibility of the criteria. Large inter-regional differences in the fulfilment of classification criteria were not found. Patients fulfilling the clinical arm were remarkably similar to patients fulfilling the imaging arm with respect to the presence of most SpA features

The feasibility and efficacy of a multidisciplinary intervention with aftercare meetings for fibromyalgia

The objective of this study is to examine the feasibility and long-term results of a 12-week multidisciplinary part-time daycare intervention with five aftercare meetings in fibromyalgia (FM) patients. One hundred and five patients diagnosed with FM started with a multidisciplinary intervention and were assessed for feasibility, functional status (Fibromyalgia Impact Questionnaire [FIQ]), and quality of life (EuroQol-5D [EQ-5D]) until 9 months after completion. The program consisted of sociotherapy, physiotherapy, psychotherapy, and creative arts therapy. Drop-out rate was 4.8%. The attendance rate of 100 patients who completed the 12-week program and five aftercare meetings was high (97.4%), just like patient and therapist satisfaction (8.2 on a 10 points scale). After the 12-week program, statistically significant improvement was seen in both FIQ and EQ-5D. This improvement was maintained after 9 months of follow-up. On average, moderate improvements were observed. Our 12-week multidisciplinary part-time daycare intervention with five aftercare meetings for FM patients is feasible and it is indicated that it can lead to sustained improvement in functional status and quality of life

Resource utilisation and direct costs in patients with recently diagnosed fibromyalgia who are offered one of three different interventions in a randomised pragmatic trial

The purpose of this study is to understand the course of costs over a 2-year period in a cohort of recently diagnosed fibromyalgia (FM) patients receiving different treatment strategies. Following the diagnosis, patients were randomly assigned to a multidisciplinary programme (MD), aerobic exercise (AE) or usual care (UC) without being aware of alternative interventions. Time between diagnosis and start of treatment varied between patients. Resource utilisation, health care costs and costs for patients and families were collected through cost diaries. Mixed linear model analyses (MLM) examined the course of costs over time. Linear regression was used to explore predictors of health care costs in the post-intervention period. Two hundred three participants, 90 % women, mean (SD) age 41.7 (9.8) years, were included in the cohort. Intervention costs per patient varied from €864 to 1392 for MD and were €121 for AE. Health care costs (excluding intervention costs) decreased after diagnosis, but before the intervention in each group, and increased again afterwards to the level close to the diagnostic phase. In contrast, patient and family costs slightly increased over time in all groups without initial decrease immediately after diagnosis. Annualised health care costs post-intervention varied between €1872 and 2310 per patient and were predicted by worse functioning and high health care costs at diagnosis. In patients with FM, health care costs decreased following the diagnosis by a rheumatologist. Offering patients a specific intervention after diagnosis incurred substantial costs while having only marginal effects on cost

Magnetic resonance imaging changes of sacroiliac joints in patients with recent-onset inflammatory back pain: inter-reader reliability and prevalence of abnormalities

To study the inter-reader reliability of detecting abnormalities of sacroiliac (SI) joints in patients with recent-onset inflammatory back pain by magnetic resonance imaging (MRI), and to study the prevalence of inflammation and structural changes at various sites of the SI joints. Sixty-eight patients with inflammatory back pain (at least four of the five following criteria: symptom onset before age 40, insidious onset, morning stiffness, duration >3 months, improvement with exercise — or three out of five of these plus night pain) were included (38% male; mean age, 34.9 years [standard deviation 10.3]; 46% HLA-B27-positive; mean symptom duration, 18 months), with symptom duration <2 years. A MRI scan of the SI joints was made in the coronal plane with the following sequences: T1-weighted spin echo, short-tau inversion recovery, T2-weighted fast-spin echo with fat saturation, and T1-spin echo with fat saturation after the administration of gadolinium. Both SI joints were scored for inflammation (separately for subchondral bone and bone marrow, joint space, joint capsule, ligaments) as well as for structural changes (erosions, sclerosis, ankylosis), by two observers independently. Agreement between the two readers was analysed by concordance and discordance rates and by kappa statistics. Inflammation was present in 32 SI joints of 22 patients, most frequently located in bone marrow and/or subchondral bone (29 joints in 21 patients). Readers agreed on the presence of inflammation in 85% of the cases in the right SI joint and in 78% of the cases in the left SI joint. Structural changes on MRI were present in 11 patients. Ten of these 11 patients also showed signs of inflammation. Agreement on the presence or absence of inflammation and structural changes of SI joints by MRI was acceptable, and was sufficiently high to be useful in ascertaining inflammatory and structural changes due to sacroiliitis. About one-third of patients with recent-onset inflammatory back pain show inflammation, and about one-sixth show structural changes in at least one SI joint

Do Smoking and Socioeconomic Factors Influence Imaging Outcomes in Axial Spondyloarthritis? Five-Year Data From the DESIR Cohort

Objective: To investigate the relationship between smoking and imaging outcomes over 5 years in axial spondyloarthritis (SpA) and to assess whether socioeconomic factors influence these relationships. Methods: Axial SpA patients from the Devenir des Spondylarthropathies Indifferérenciées Récentes cohort were included. The following 4 imaging outcomes were assessed by 3 central readers at baseline, 2 years, and 5 years: spine radiographs (using the modified Stoke Ankylosing Spondylitis Spine Score [mSASSS]), sacroiliac (SI) joint radiographs (using the modified New York criteria), magnetic resonance imaging (MRI) of the spine (using the Spondyloarthritis Research Consortium of Canada [SPARCC] score), and MRI of the SI joint (using the SPARCC score). The explanatory variable of interest was smoking status at baseline. Interactions between smoking and socioeconomic factors (i.e., job type [blue-collar or manual work versus white-collar or nonmanual work] and education [low versus high]) were first tested, and if significant, analyses were run using separate strata. Generalized estimating equations models were used, with adjustments for confounders. Results: In total, 406 axial SpA patients were included (52% male, 40% smokers, and 18% blue collar). Smoking was independently associated with more MRI-detected SI joint inflammation at each visit over the 5 years, an effect that was seen only in patients with blue-collar professions (β = 5.41 [95% confidence interval (95% CI) 1.35, 9.48]) and in patients with low education levels (β = 2.65 [95% CI 0.42,4.88]), using separate models. Smoking was also significantly associated with spinal inflammation (β = 1.69 [95% CI 0.45, 2.93]) and SI joint damage (β = 0.57 [95% CI 0.18, 0.96]) across all patients, irrespective of socioeconomic factors and other potential confounders. Conclusion: Strong associations were found between smoking at baseline and MRI-detected SI joint inflammation at each visit over a time period of 5 years in axial SpA patients with a blue-collar job or low education level. These findings suggest a possible role for mechanical stress amplifying the effect of smoking on axial inflammation in axial SpA.publishersversionpublishe