The Scleroderma Patient-centered Intervention Network (SPIN) Cohort: protocol for a cohort multiple randomised controlled trial (cmRCT) design to support trials of psychosocial and rehabilitation interventions in a rare disease context

Scleroderma: Assessment of posture, balance and pulmonary function in a cross-sectional controlled study

BACKGROUND

Systemic sclerosis leads to significant physical limitations in patients, such as diffuse weakness, skin sclerosis, loss of joint function and lung damage. This study aimed to assess posture and balance in systemic sclerosis patients and secondarily to verify correlations between such measurements and lung function.

METHODS

Thirty-one patients and a similar number of control subjects matched for age, gender, weight, height and body mass index underwent postural assessment using photogrammetry, balance measurement using the Berg Balance Scale and stabilometry, and pulmonary function tests.

FINDINGS

When compared to healthy volunteers, the patients had postural deviations in hip angle (P=0.009 in anterior view and P=0.028 for the right side), horizontal alignment of the pelvis (P=0.002 for the right side and P=0.004 for the left side), vertical alignment of the trunk (P=0.012 for the right side) and ankle angle (P=0.019 for the right side). Postural balance was similar between the two groups as assessed by the Berg Balance Scale and stabilometry. We observed significant correlations between balance measures and posture variables involving the knee and ankle, and between postural control and lung function (ratio between forced vital capacity and diffusing capacity for carbon monoxide).

INTERPRETATION

Our results suggest that posture and balance should be assessed in systemic sclerosis patients in clinical practice, as significant postural changes and compensations are needed to maintain balance. Furthermore, it is important to monitor lung function because vascular injury impacts on postural control in these patients.

Psychosocial Aspects of Scleroderma

Patients with systemic sclerosis (SSc; also called scleroderma) have to cope with not only the physical impacts of the disease but also the emotional and social consequences of living with the condition. Because there is no cure for SSc, improving quality of life is a primary focus of treatment and an important clinical challenge. This article summarizes significant problems faced by patients with SSc, including depression, anxiety, fatigue, sleep disruption, pain, pruritus, body image dissatisfaction, and sexual dysfunction, and describes options to help patients cope with the consequences of the disease.

Systemic sclerosis

Systemic sclerosis is a complex autoimmune disease characterized by a chronic and frequently progressive course and by extensive patient-to-patient variability. Like other autoimmune diseases, systemic sclerosis occurs more frequently in women, with a peak of onset in the fifth decade of life. The exact cause of systemic sclerosis remains elusive but is likely to involve environmental factors in a genetically primed individual. Pathogenesis is dominated by vascular changes; evidence of autoimmunity with distinct autoantibodies and activation of both innate and adaptive immunity; and fibrosis of the skin and visceral organs that results in irreversible scarring and organ failure. Intractable progression of vascular and fibrotic organ damage accounts for the chronic morbidity and high mortality. Early and accurate diagnosis and classification might improve patient outcomes. Screening strategies facilitate timely recognition of life-threatening complications and initiation of targeted therapies to halt their progression. Effective treatments of organ-based complications are now within reach. Discovery of biomarkers - including autoantibodies that identify patient subsets at high risk for particular disease complications or rapid progression - is a research priority. Understanding the key pathogenetic pathways, cell types and mediators underlying disease manifestations opens the door for the development of targeted therapies with true disease-modifying potential. For an illustrated summary of this Primer, visit: http://go.nature.com/lchkcA.

The DiReCT study - improving recruitment into clinical trials: a mixed methods study investigating the ethical acceptability, feasibility and recruitment yield of the cohort multiple randomised controlled trials design

BACKGROUND

The 'cohort multiple Randomised Controlled Trial' (cmRCT) design has been proposed as a potential solution to poor recruitment into clinical trials. The design randomly selects participants eligible for experimental treatments from a pre-enrolled cohort of patients, recruiting participants to multiple trials from a single cohort. Controls remain unaware of their participation in specific trials.

METHODS

We undertook a mixed methods study to determine the ethical acceptability, the proportion of patients in a routine service consenting to cohort participation, the proportion of these who would consent to being hypothetically randomly selected to receive new treatments, and the views of clinicians on the acceptability of the design. We submitted our cmRCT design for ethical review and recruited participants from people with anxiety and depression attending a community mental health service of twenty-one clinicians. We recorded the proportion of patients who were offered participation in the DiReCT study and the proportion that consented to researcher contact, medical record sharing, and who accepted to be randomly allocated to active treatment procedures in future hypothetical unspecified clinical trials. We used a thematic framework analysis to analyse clinician interviews.

RESULTS

We obtained a favourable ethical opinion from the UK Health Research Authority. Clinicians approached 131/752 (17%) potentially eligible participants for consent. Of these 131, 84 (64%) initially consented to be contacted by a researcher and all but one consented to being randomised into future trials. We confirmed consent for 71 (54%) of participants approached by clinicians, of whom 69 (53%) consented to being randomised into hypothetical future trials, 9% (69/752) of all potentially eligible patients. The interviewed clinicians described issues impacting on their ability to recruit participants in terms of clinical concerns for patient wellbeing, work pressure, their views of both general research and the specific DiReCT study, and how they viewed patients' responses to being offered participation in the study.

CONCLUSIONS

The cmRCT system offers the potential to improve the recruitment into clinical trials and is acceptable ethically and to many patients. Overcoming the multiple factors driving the difficulties clinicians experience in patient recruitment is likely to require the application of significant implementation science-informed effort.

An assessment of the measurement equivalence of English and French versions of the Center for Epidemiologic Studies Depression (CES-D) Scale in systemic sclerosis

Objectives

Center for Epidemiologic Studies Depression (CES-D) Scale scores in English- and French-speaking Canadian systemic sclerosis (SSc) patients are commonly pooled in analyses, but no studies have evaluated the metric equivalence of the English and French CES-D. The study objective was to examine the metric equivalence of the CES-D in English- and French-speaking SSc patients.

Methods

The CES-D was completed by 1007 English-speaking and 248 French-speaking patients from the Canadian Scleroderma Research Group Registry. Confirmatory factor analysis (CFA) was used to assess the factor structure in both samples. The Multiple-Indicator Multiple-Cause (MIMIC) model was utilized to assess differential item functioning (DIF).

Results

A two-factor model (Positive and Negative affect) showed excellent fit in both samples. Statistically significant, but small-magnitude, DIF was found for 3 of 20 CES-D items, including items 3 (Blues), 10 (Fearful), and 11 (Sleep). Prior to accounting for DIF, French-speaking patients had 0.08 of a standard deviation (SD) lower latent scores for the Positive factor (95% confidence interval [CI]−0.25 to 0.08) and 0.09 SD higher scores (95% CI−0.07 to 0.24) for the Negative factor than English-speaking patients. After DIF correction, there was no change on the Positive factor and a non-significant increase of 0.04 SD on the Negative factor for French-speaking patients (difference = 0.13 SD, 95% CI−0.03 to 0.28).

Conclusions

The English and French versions of the CES-D, despite minor DIF on several items, are substantively equivalent and can be used in studies that combine data from English- and French-speaking Canadian SSc patients.

The comparability of English, French and Dutch scores on the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F): an assessment of differential item functioning in patients with systemic sclerosis

OBJECTIVE

The Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) is commonly used to assess fatigue in rheumatic diseases, and has shown to discriminate better across levels of the fatigue spectrum than other commonly used measures. The aim of this study was to assess the cross-language measurement equivalence of the English, French, and Dutch versions of the FACIT-F in systemic sclerosis (SSc) patients.

METHODS

The FACIT-F was completed by 871 English-speaking Canadian, 238 French-speaking Canadian and 230 Dutch SSc patients. Confirmatory factor analysis was used to assess the factor structure in the three samples. The Multiple-Indicator Multiple-Cause (MIMIC) model was utilized to assess differential item functioning (DIF), comparing English versus French and versus Dutch patient responses separately.

RESULTS

A unidimensional factor model showed good fit in all samples. Comparing French versus English patients, statistically significant, but small-magnitude DIF was found for 3 of 13 items. French patients had 0.04 of a standard deviation (SD) lower latent fatigue scores than English patients and there was an increase of only 0.03 SD after accounting for DIF. For the Dutch versus English comparison, 4 items showed small, but statistically significant, DIF. Dutch patients had 0.20 SD lower latent fatigue scores than English patients. After correcting for DIF, there was a reduction of 0.16 SD in this difference.

CONCLUSIONS

There was statistically significant DIF in several items, but the overall effect on fatigue scores was minimal. English, French and Dutch versions of the FACIT-F can be reasonably treated as having equivalent scoring metrics.