Systemic Sclerosis-Associated Interstitial Lung Disease: Lessons from Clinical Trials, Outcome Measures, and Future Study Design

The Performance of Pulmonary Function Tests in Predicting Systemic Sclerosis-Interstitial Lung Disease in the European Scleroderma Trial and Research Database

BACKGROUND AND OBJECTIVES

In SSc, ILD is a major cause of morbidity and mortality. We aimed to investigate the performance of DLCO (diffusing capacity of lung carbon monoxide) and FVC (forced vital capacity) delta change (Δ) and baseline values in predicting the development of SSc-ILD.

METHODS

Longitudinal data of DLCO, FVC, and ILD on the HRCT of SSc patients from the EUSTAR database were evaluated at baseline (t0) and after 12 (±4) (t1) and 24 (±4) (t2) months.

RESULTS

474/17805 patients were eligible for the study (403 females); 46 (9.7%) developed ILD at t2. Positivity for anti-topoisomerase antibodies (117 patients) showed an association with ILD development at t2 (p = 0.0031). Neither the mean t0 to t1 change (Δ) of DLCO nor the mean t0 to t1 FVCΔ predicted the appearance of ILD at t2. Investigating the possible role of baseline DLCO and FVC values in predicting ILD appearance after 24 (±4) months, we observed a moderate predictive capability of t0 DLCO < 80%, stronger than that of FVC < 80%.

CONCLUSIONS

We suggest that an impaired baseline DLCO may be predictive of the appearance of ILD after 2 years of follow-up. This result advances the hypothesis that a reduction in gas exchange may be considered an early sign of lung involvement. However, further rigorous studies are warranted to understand the predictive role of DLCO evaluation in the course of SSc.

Assessment of disease outcome measures in systemic sclerosis

The assessment of disease activity in systemic sclerosis (SSc) is challenging owing to its heterogeneous manifestations across multiple organ systems, the variable rate of disease progression and regression, and the relative paucity of patients in early-phase therapeutic trials. Despite some recent successes, most clinical trials have failed to show efficacy, underscoring the need for improved outcome measures linked directly to disease pathogenesis, particularly applicable for biomarker studies focused on skin disease. Current outcome measures in SSc-associated interstitial lung disease and SSc skin disease are largely adequate, although advancing imaging technology and the incorporation of skin mRNA biomarkers might provide opportunities for earlier detection of the therapeutic effect. Biomarkers can further inform pathogenesis, enabling early phase trials to act as reverse translational studies through the incorporation of routine high-throughput sequencing.

Outcome measurement instrument selection for lung physiology in systemic sclerosis associated interstitial lung disease: A systematic review using the OMERACT filter 2.1 process

OBJECTIVE

The Outcome Measures in Rheumatology (OMERACT) is a research organization focused on improving health care outcomes for patients with autoimmune and musculoskeletal diseases. The Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD) Working Group on Lung Physiology is a group within OMERACT charged with identifying outcome measures that should be implemented in studies of patients with CTD-ILD. The OMERACT Filter 2.1 is an evidence-based algorithm used to identify outcome measures that are truthful, feasible, and able to discriminate between groups of interest. Our objective was to summate evidence (published literature, key opinion leader input, patient perspectives) that would influence the CTD-ILD Working Group's vote to accept or reject the use of two measures of lung physiology, the forced vital capacity (FVC) and the diffusion capacity of carbon monoxide (DLco) for use in randomized controlled trials (RTCs) and longitudinal observational studies (LOSs) involving patients with systemic sclerosis associated ILD (SSc-ILD).

METHODS

Patient Research Partners (those afflicted with SSc-ILD) and the CTD-ILD Working Group on Lung Physiology were polled to assess their opinion on the FVC and DLco in terms of feasibility; the CTD-ILD Working Group was also queried on these instruments' face and content validity. We then conducted a systematic literature review to identify articles in the SSc-ILD population that assessed the following measurement properties of FVC and DLco: (1) construct validity, (2) test-retest reliability, (3) longitudinal construct validity, (4) clinical trial discrimination/sensitivity to detect change in clinical trials, and (5) thresholds of meaning. Results were summarized in a Summary of Measurement Properties (SOMP) table for each instrument. OMERACT CTD-ILD Working Group members discussed and voted on the strength of evidence supporting these two instruments and voted to endorse, provisionally endorse, or not endorse either instrument.

RESULTS

Forty Patient Research Partners reported these two measures are feasible (are not an unnecessary burden or represent an infeasible longitudinal assessment of their disease). A majority of the 18 CTD-ILD Working Group members voted that both the FVC and DLco are feasible and have face and content validity. The systematic literature review returned 1,447 non-duplicated articles, of which 177 met eligibility for full text review. Forty-eight studies (13 RCTs, 35 LOSs) were included in the qualitative analysis. The FVC SOMP table revealed high quality, consistent data with evidence of good performance for all five measurement properties, suggesting requisite published evidence to proceed with endorsement. The DLco SOMP table showed a lack of data to support test-retest reliability and inadequate evidence to support clinical trial discrimination. There was unanimous agreement (15 [100%]) among voting CTD-ILD Working Group members to endorse the FVC as an instrument for lung physiology in RCTs and LOSs in SSc-ILD. Based on currently available evidence, DLco did not meet the OMERACT criteria and is not recommended for use in RCTs to represent lung physiology of SSc-ILD. The OMERACT Technical Advisory Group agreed with these decisions.

CONCLUSION

The OMERACT Filter 2.1 was successfully applied to the domain of lung physiology in patients with SSc-ILD. The FVC was endorsed for use in RCTs and LOSs based on the Working Group's vote; DLco was not endorsed.

Functional Disability Among Systemic Sclerosis Patients: Relation to Disease Characteristics and Quality of Life Parameters

BACKGROUND

Disability in patients with scleroderma (SSc) has been associated with poor health-related quality of life (HRQoL) in all dimensions, including physical, psychological, and social dimensions.

OBJECTIVE

This study was conducted to examine different factors that may be associated with functional disability and poor HRQoL, with the aim of targeting these factors in the future to improve physical activity, functional outcomes, and HRQoL.

METHODS

A single-center cross-sectional study was conducted on 38 patients with SSc to compare characteristics between patients with and without disability using the Health Assessment Questionnaire Disability Index (HAQ-DI). Quality of life was assessed using the Short Form-36 (SF-36). Linear regressions were performed to examine variables contributing to functional disability.

RESULTS

Almost 65.78% (n = 25) of patients in the study group reported functional disability. The presence of functional disability was associated with reduced HRQoL, as reflected by physical function (P = 0.0001), physical role (P = 0.016), bodily pain (P = 0.001), general health (P = 0.002), social functional (P = 0.002), emotional role (P = 0.042), and mental health (P = 0.025) domains of the SF-36 score. Multiple linear regression indicated that the main predictive factors associated with HAQ-DI were the modified Hand Mobility in Scleroderma; modified Rodnan skin score; DIstance walked in 6 minutes, BOrg dyspnea index, and SAturation of oxygen at 6 minutes (DIBOSA); and Fatigue Severity Scale among patients with SSc.

CONCLUSION

In patients with SSc, recognizing the relationships between clinical findings and functional disability will allow the development of further management strategies to minimize disease severity and enhance HRQoL.

Short-Term Lung Function Changes and Predictors of Progressive Systemic Sclerosis-Related Interstitial Lung Disease

BACKGROUND

Systemic sclerosis (SSc) involves multiple organ systems and has the highest mortality among connective tissue diseases. Interstitial lung disease is the most common cause of death among SSc patients and requires closer studies and follow-ups. This study aimed to identify lung function changes and predictors of progressive disease in systemic sclerosis-related interstitial lung disease (SSc-ILD).

METHODS

A retrospective study extracted SSc patients from an electronic database January 2002-July 2019. Eligible cases were SSc patients >age 15 diagnosed with SSc-ILD. Factors associated with progressive disease were analyzed by univariate and multivariate logistic regression analyses.

RESULTS

Seventy-eight SSc-ILD cases were enrolled. Sixty-five patients (83.3%) were female, with mean age of 44.7±14.4, and 50 (64.1%) were diffuse type SSc-ILD. Most SSc-ILD patients had crackles (75.6%) and dyspnea on exertion (71.8%), and 19.2% of the SSc-ILD patients had no abnormal respiratory symptoms but had abnormal chest radiographic findings. The most common diagnosis of SSc-ILD patients was non-specific interstitial pneumonia (43.6%). The lung function values of diffusing capacity of the lung for carbon monoxide (DLCO) and DLCO per unit alveolar volume declined in progressive SSc-ILD during a 12-month follow-up. Male and no previous aspirin treatment were the two significant predictive factors of progressive SSc-ILD with adjusted odds ratios of 5.72 and 4.99, respectively.

CONCLUSION

This present study showed that short-term lung function had declined during the 12-month follow-up in progressive SSc-ILD. The predictive factors in progressive SSc-ILD were male sex and no previous aspirin treatment. Close follow-up of the pulmonary function tests is necessary for early detection of progressive disease.

Treatment of systemic sclerosis-associated interstitial lung disease: Lessons from clinical trials

Systemic sclerosis-associated interstitial lung disease remains a leading cause of mortality. Despite decades of clinical trials, the treatment effects of disease modifying anti-rheumatic drugs continue to be modest and there remains a great need for therapies that attenuate and hopefully ameliorate parenchymal lung disease. In this review, we highlight the key clinical trials that have shaped the management strategies employed by the authors, providing their strength of recommendation based on level of evidence. We also review lessons learned in more recent years, suggesting a benefit in targeting patients with subclinical interstitial lung disease with high risk for progression early in the disease course, as well as the benefit seen in a large clinical trial leading to the first Food and Drug Administration-approved treatment for systemic sclerosis-associated interstitial lung disease. These lessons come in a context of heterogeneity of patient populations and response to therapy, as well as the inherent constraints of time-limited studies to detect meaningful outcomes for patients.

Involvement of the myeloid cell compartment in fibrogenesis and systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune fibrotic disease of unknown aetiology that is characterized by vascular changes in the skin and visceral organs. Autologous haematopoietic stem cell transplantation can improve skin and organ fibrosis in patients with progressive disease and a high risk of organ failure, indicating that cells originating in the bone marrow are important contributors to the pathogenesis of SSc. Animal studies also indicate a pivotal function of myeloid cells in the development of fibrosis leading to changes in the tissue architecture and dysfunction in multiple organs such as the heart, lungs, liver and kidney. In this Review, we summarize current knowledge about the function of myeloid cells in fibrogenesis that occurs in patients with SSc. Targeted therapies currently in clinical studies for SSc might affect myeloid cell-related pathways. Therefore, myeloid cells might be used as cellular biomarkers of disease through the application of high-dimensional techniques such as mass cytometry and single-cell RNA sequencing.

Pulmonary function tests as outcomes for systemic sclerosis interstitial lung disease

Interstitial lung disease (ILD) is the leading cause of morbidity and mortality in systemic sclerosis (SSc). We performed a systematic review to characterise the use and validation of pulmonary function tests (PFTs) as surrogate markers for systemic sclerosis-associated interstitial lung disease (SSc-ILD) progression.Five electronic databases were searched to identify all relevant studies. Included studies either used at least one PFT measure as a longitudinal outcome for SSc-ILD progression (i.e. outcome studies) and/or reported at least one classical measure of validity for the PFTs in SSc-ILD (i.e. validation studies).This systematic review included 169 outcome studies and 50 validation studies. Diffusing capacity of the lung for carbon monoxide (DLCO) was cumulatively the most commonly used outcome until 2010 when it was surpassed by forced vital capacity (FVC). FVC (% predicted) was the primary endpoint in 70.4% of studies, compared to 11.3% for % predicted DLCO Only five studies specifically aimed to validate the PFTs: two concluded that DLCO was the best measure of SSc-ILD extent, while the others did not favour any PFT. These studies also showed respectable validity measures for total lung capacity (TLC).Despite the current preference for FVC, available evidence suggests that DLCO and TLC should not yet be discounted as potential surrogate markers for SSc-ILD progression.

Interstitial lung disease points to consider for clinical trials in systemic sclerosis

Interstitial lung disease causes major morbidity and mortality in patients with systemic sclerosis (SSc-ILD). Large randomized clinical trials in SSc-ILD have provided important information regarding the feasibility, reliability and validity of outcome measures. Forced vital capacity percentage predicted should be considered as a primary outcome measure, with inclusion of appropriate radiological and patient-reported measures. We provide practical recommendations for trial design in SSc-ILD.

Mycophenolate mofetil following cyclophosphamide in worsening systemic sclerosis-associated interstitial lung disease

Objectives

Randomized controlled trials have shown that cyclophosphamide (CYC) was an option in systemic sclerosis-associated interstitial lung disease (SSc-ILD). The observed improvement disappeared after CYC was stopped suggesting that a maintenance regimen was mandatory. Immunosuppressants were suggested to be more effective in patients with worsening (i.e., with worsening of dyspnea and/or pulmonary functional tests) SSc-ILD. We aimed to assess the efficacy of mycophenolate mofetil (MMF) as a maintenance regimen after CYC in worsening SSc-ILD.

Methods

All patients (n = 20) with worsening SSc-ILD were retrospectively included. Treatment consisted of 6 to 12 monthly pulses of CYC followed by MMF and response was assessed by the evolution of the forced vital capacity (FVC) and carbon monoxide diffusing capacity (DLCO) during follow-up.

Results

At the end of CYC pulses, SSc-ILD had improved in 7 (35%) patients, stabilized in 10 (50%) (i.e., 85% of responders) and worsened in 3 (15%) when compared to baseline. After 6 months of MMF, 70% were still responders while 30% had worsened when compared to baseline (i.e., before CYC). After 12 months on MMF, 55% were responders and 45% had worsened when compared to baseline. Evolution of the FVC slope significantly improved on CYC as well as on MMF.

Conclusions

A strategy combining IV CYC followed by maintenance MMF for worsening SSc-ILD was associated with stabilization or improvement of pulmonary function tests in only 55% of patients after 12 months of MMF. This suggests that careful monitoring for worsening is mandatory during MMF maintenance and that improvement in managing worsening SSc-ILD is still needed.

An Open-label, Phase II Study of the Safety and Tolerability of Pirfenidone in Patients with Scleroderma-associated Interstitial Lung Disease: the LOTUSS Trial

OBJECTIVE

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) shares a number of clinical features and pathogenic mechanisms with idiopathic pulmonary fibrosis (IPF). This study was designed to evaluate the tolerability of the IPF treatment pirfenidone in SSc-ILD. The known gastrointestinal, skin, and liver adverse events (AE) of pirfenidone are of importance given the involvement of these organs in SSc.

METHODS

All patients received pirfenidone and were randomized 1:1 to either a 2- or 4-week titration starting at 801 mg/day and finishing at a maintenance dose of 2403 mg/day. Patients received pirfenidone for 16 weeks in total. Assessments included treatment-emergent AE (TEAE) and exploratory disease outcomes.

RESULTS

Sixty-three patients were randomized; 96.8% experienced a TEAE and more patients reported TEAE during the titration versus the maintenance period. The most commonly reported TEAE were consistent with those observed for pirfenidone in IPF (nausea, headache, fatigue) and were similar regardless of titration schedule. More patients discontinued treatment because of TEAE in the 2- versus 4-week titration group (5 vs 1, respectively); all discontinuation events occurred > 3 weeks after reaching the full dose of pirfenidone. Mycophenolate mofetil (MMF), taken by 63.5% of patients in addition to pirfenidone, did not appear to affect tolerability. Exploratory disease outcomes remained largely unchanged.

CONCLUSION

Pirfenidone showed an acceptable tolerability profile in SSc-ILD, although a longer titration may be associated with better tolerability. Tolerability was not affected by concomitant MMF. The present findings support further investigation of pirfenidone in future clinical trials in patients with SSc-ILD.

TRIAL REGISTRATION

ClinicalTrials.gov; www.clinicaltrials.gov NCT01933334.

Cyclophosphamide versus mycophenolate mofetil in scleroderma interstitial lung disease (SSc-ILD) as induction therapy: a single-centre, retrospective analysis

BACKGROUND

Scleroderma is a systemic autoimmune disease characterized mainly by skin manifestations and involvement of various visceral organs, especially the lungs. Lung involvement is the leading cause of mortality in patients with scleroderma. There are data to suggest that cyclophosphamide (CYC) and mycophenolate mofetil (MMF) are effective in the management of scleroderma interstitial lung disease (SSc-ILD) but no head to head comparative data are available to date.

METHODS

For the last 3 years, patients with SSc-ILD have been treated at our centre by protocol-based administration of intravenous CYC and MMF. Results of lung function tests (spirometry) were recorded at baseline, 3 months and 6 months in every patient. The clinical records of patients with systemic sclerosis and significant ILD, who were not previously exposed to any immunosuppressant and were treated with MMF OR CYC, were reviewed. The efficacy of treatment was assessed by the change in forced vital capacity on spirometry.

RESULTS

Of the total 57 patients included in the analysis, 34 were treated with MMF and 23 were treated with CYC. Mean duration of illness was 4.19 ± 2.82 years in the MMF and 6.04 ± 5.96 years in the CYC group. After 6 months of therapy, FVC increased by 10.84 ± 13.81 % in the CYC group and by 6.07 ± 11.92 % in the MMF group. This improvement from baseline was statistically significant in both groups (P < 0.01). The improvement was comparable with no statistically significant differences between groups (P = 0.373). There were no major adverse events reported in either arm.

CONCLUSION

Both MMF and CYC were equally effective in stabilizing lung function in patients with scleroderma and ILD.

Predictors of lung function decline in scleroderma-related interstitial lung disease based on high-resolution computed tomography: implications for cohort enrichment in systemic sclerosis-associated interstitial lung disease trials

BACKGROUND

The extent of lung involvement visualized by high-resolution computed tomography (HRCT) is a predictor of decline in forced vital capacity (FVC) in scleroderma-interstitial lung disease. Our objective was to evaluate the performance of three different HRCT-defined staging systems in the Scleroderma Lung Study I (SLS I) over a 1-year period.

METHODS

We assessed two visual semiquantitative scores: the maximum fibrosis score (MaxFib, the fibrosis score in the zone of maximal lung involvement) and visual assessment of total lung involvement (TLI) as proposed by Goh and Wells. In addition, we evaluated the computer-aided diagnosis and calculated the quantitative percentage with fibrosis (QLF) and TLI.

RESULTS

The mean duration of the disease was 3.2 years, and the mean FVC was 67.7 %. Regardless of the staging system used, a greater degree of fibrosis/TLI on HRCT scans was associated with a greater decline in FVC in the placebo group. Using the MaxFib and QLF, the mean absolute changes in FVC from baseline were 0.1% and -1.4%, respectively, in <25% lung involvement vs. a change of -6.2% and -6.9%, respectively, with >25% involvement (negative score denotes worsening in FVC). Conversely, cyclophosphamide was able to stabilize decline in FVC in subjects with greater degree of involvement detected by HRCT. Using the visual MaxFib and QLF, the mean absolute improvements in FVC were 1.2 and 1.1, respectively, with >25% involvement.

CONCLUSIONS

HRCT-defined lung involvement was a predictor of decline in FVC in SLS I. The choice of staging system for cohort enrichment in a clinical trial depends on feasibility.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00004563 (Scleroderma Lung Study I) ISRCTN15982171. Registered 19 Aug 2015.

Where are we going in the management of interstitial lung disease in patients with systemic sclerosis?

Interstitial lung disease (ILD) affects about 90% of patients with systemic sclerosis (SSc). It is associated with a restrictive lung disease in only 30% of patients and is progressive in an even lower percentage. A low forced vital capacity at presentation, an extent of lung fibrosis >20% as detected by lung high-resolution computed tomography, high serum interleukin-6 levels, anti-topoisomerase I antibody positivity and diffuse cutaneous SSc are each associated with SSc-ILD progression. However, no such association is absolute. Treating patients with a recent deterioration of lung function may allow to capture those with active disease. To date, cyclophosphamide (CYC) is the only drug found to stabilize or improve lung function in randomized clinical trials, but its small beneficial effect is short lived. Therefore, immunosuppressive maintenance therapy after CYC treatment is warranted. At present, however, the best therapeutical strategy after CYC therapy both in responders and in non-responders to CYC is still controversial. Based on a review of the literature, we suggest an approach to the management of SSc-ILD.

[Use of pulmonary function tests and biomarkers studies to diagnose and follow-up interstitial lung disease in systemic sclerosis]

Interstitial lung disease (ILD) is becoming one of the main causes of death of patients with systemic sclerosis (SSc). The prevalence of ILD associated with SSc (SSc-ILD) varies from 33% to 100% according to diagnostic methods. Clinical features such as dyspnea on exertion, dry cough, and chest pains are not specific and usually late-appearing, implying more specific tests in the diagnostic, prognosis, and follow-up of ILD in patients with SSc. High resolution thoracic CT scanner (HRCT) is more sensitive than chest X-ray in the detection of SSc-ILD. Pulmonary function tests (PFT) are non-invasive and periodically used to assess the impacts of SSc on respiratory function. Diagnostic values of bronchoalveolar lavage and histological examination on lung biopsy are controversial. However, these techniques are essential for studying cellular and molecular mechanisms underlying the pathophysiology of SSc-ILD. Several biomarkers such as surfactant-A (SP-A), -D (SP-D), mucin-like high molecular weight glycoprotein (KL-6), and chemokine CCL-18 have been implicated in SSc-PID. Serum levels of these proteins are correlated with the severity of SSc-ILD, as assessed by HRCT and/or PFT. Finally, alveolar concentration of exhaled nitric oxide can be used to screen SSc patients with high risk of deterioration of respiratory function, in whom immunosuppressant treatment could be useful in preventing the evolution to irreversible lung fibrosis.

Mycophenolate versus cyclophosphamide for progressive interstitial lung disease associated with systemic sclerosis: a 2-year case control study

OBJECTIVE

Cyclophosphamide is considered the treatment of choice for interstitial lung disease (ILD) secondary to systemic sclerosis (SSc), albeit having a minimal effect. Although controlled evidence does not exist, mycophenolate is used increasingly in clinical practice as an alternative. We aimed to compare the long-term efficacy of these drugs.

METHODS

Patients from our SSc cohort who received mycophenolate for over 1 year for progressive ILD were 1:1 matched for age, gender, and baseline forced vital capacity (FVC ±3 %) with cyclophosphamide-treated patients. Changes in FVC, total lung capacity (TLC), diffusion capacity for carbon monoxide (DLCO), and high-resolution computed tomography (HRCT) scans were compared between groups. Changes in pulmonary function tests (PFTs) over at least 1 year in six unmatched control patients, who had denied mycophenolate or cyclophosphamide, also were examined.

RESULTS

FVC, TLC, and DLCO did not change significantly in either mycophenolate (from 79.0 ± 12.5 to 80.2 ± 8.1 to 81.2 ± 11.4, from 71.5 ± 16.1 to 74.3 ± 10.8 to 71.8 ± 13.0, from 56.8 ± 12.0 to 55.2 ± 9.9 to 50.6 ± 8.5, respectively) or cyclophosphamide group (from 77.3 ± 12.5 to 79.7 ± 10.3 to 82.5 ± 12.9, from 64.7 ± 14.9 to 68.6 ± 16.0 to 66.1 ± 15.5, from 53.1 ± 14.3 to 56.4 ± 13.5 to 56.3 ± 6.7, respectively), after 1 or 2 years of treatment. PFTs also remained stable in the control group. In either the mycophenolate or cyclophosphamide groups, six patients remained stable, three improved, and one deteriorated according to the definitions of the American Thoracic Society. However, and despite the fact that patients in the cyclophosphamide group had more extended ILD at baseline, a deterioration of lung HRCT findings at 2 years was noticed after mycophenolate (from 10.0 ± 8.9 to 12.7 ± 8.2, p = 0.039) but not after cyclophosphamide.

CONCLUSIONS

Although these results derive from patients selected for receiving at least 1 year of treatment and therefore they do not represent an intention-to-treat cohort, an eagerness to replace cyclophosphamide by mycophenolate in SSc-associated ILD treatment is not supported.

OMERACT 10 Patient Perspective Virtual Campus: Valuing Health; Measuring Outcomes in Rheumatoid Arthritis Fatigue, RA Sleep, Arthroplasty, and Systemic Sclerosis; and Clinical Significance of Changes in Health

This workshop reviewed progress in a number of areas related to patient perspective outcomes that were not specifically included within other areas of the program. A substantial review of the work of the valuing health outcomes group (the “QALY” working group) with participation and feedback from the plenary audience resulted in guidance to refocus on the use of patient preferences in the elaboration of more robust outcome measures for patient-reported outcomes and life impact measures. Progress and developments in the areas of fatigue and sleep in rheumatoid arthritis, outcome measures in hip and knee arthroplasty clinical trials, and scleroderma were outlined, and the challenge of truly understanding the nature of clinically important improvement was reviewed.