Reliability of skin involvement measures in scleroderma. The UK Scleroderma Study Group

Clinical approach to scleroderma

Systemic sclerosis (SSc) is a heterogenous disease with a morbidity and mortality that varies widely. Nonetheless, the future clinical course of an individual patient can be estimated based on the severity of skin and internal organ involvement within the first several years of the disease. Patients with limited cutaneous SSc (ISSc) have skin thickening below the elbows or knees and may have face and neck involvement. Patients with this subtype of SSc have Raynaud's phenomenon, digital ulcers, and esophageal dysfunction. Significant morbidity and mortality arises in those patients with ISSc who develop interstitial lung disease or pulmonary artery hypertension. Patients with diffuse cutaneous SSc (dSSc) have skin thickening above the elbows and knees or on the trunk. These patients have a more abrupt onset of disease, often with constitutional symptoms and arthalgias. Severe heart, lung, gut, and renal involvement, if it occurs, tends to develop within the first 5 years of disease, especially within the first several years. Patients with significant internal organ involvement have a poorer prognosis than patients who do not. The goals of the initial history and physical and laboratory examinations are to classify the type of scleroderma as ISSc or dSSc, to estimate disease duration, and to define the extent and severity of organ involvement. Treatment of SSc is organ based. Treatment may reduce morbidity associated with Raynaud's phenomenon, digital ulcers, esophageal dysmotility, esophageal reflux, gut dysmotility, arthralgias, myositis, and pulmonary artery hypertension. Therapy may stabilize lung function in patients with interstitial lung disease with alveolitis and stabilize renal function in patients with renal crisis. The overall prognosis for patients with SSc appears to be improving. Patients with early dSSc should be considered for enrollment onto protocol testing of potential disease-modifying therapies.

Treatment of systemic sclerosis

Guidelines for the conduct of clinical trials in progressive systemic sclerosis have been recommended to determine drug efficacy better. To date, the results of disease-modifying drugs in scleroderma have been disappointing. The treatment of esophagitis has been revolutionized by omeprazole. Raynaud's phenomenon can be treated with calcium channel blockers and iloprost. Scleroderma renal crisis can be treated with aggressive blood pressure control using angiotensin converting enzyme inhibitors. The best treatment for rapidly progressive scleroderma lung is still unknown. Future treatments in scleroderma should be tested with the use of recommended guidelines.

Interobserver reliability in measuring flexion, internal rotation, and external rotation of the hip using a plurimeter

OBJECTIVE

To determine reliability of the measurement of hip movements (flexion, internal rotation, and external rotation) between medical practitioners.

METHODS

Six clinicians carried out measurements of hip movements on each of six patients with osteoarthritis of one hip, using a specifically designed plurimeter.

RESULTS

There was no evidence of any systematic difference between medical practitioners in the measurement of hip flexion, internal rotation, or external rotation. The degree of agreement was greatest for hip flexion.

CONCLUSIONS

This study has shown that measurement of range of movement at the hip is repeatable between practitioners using a simple plurimeter and may represent an examination that is suitable for monitoring progress and treatment.

Scleroderma

In practice, the classification of scleroderma is less problematic than that of most other connective tissue diseases given the distinctive pattern of skin involvement. Classification of early and limited disease is more problematic and is difficult to separate from severe forms of Raynaud's phenomenon. Division of scleroderma into two groups depending on the presence or absence, early in the disease, of truncal skin involvement makes biological and clinical sense. Measurement using a clinical skin score remains the best approach to monitoring disease progress.

Disease assessment indices: activity, damage and severity

The methodology for developing and assessing disease status measures is now well-advanced. For some diseases, in particular SLE and RA, these methods have been applied and instruments either are being or have been validated. For other conditions, such as ankylosing spondylitis and Behçet's disease, there is still a need for reliable measures to be proposed and evaluated.

Guidelines for clinical trials in systemic sclerosis (scleroderma). I. Disease-modifying interventions. The American College of Rheumatology Committee on Design and Outcomes in Clinical Trials in Systemic Sclerosis

OBJECTIVE

To develop guidelines for therapeutic trials designed to improve the overall course of systemic sclerosis (SSc), that is, to reduce the development of significant organ damage or death.

METHODS

A committee developed general guidelines for patient inclusion and exclusion criteria, randomization, blinding of patients and physicians, controls, duration of the trial, investigator training, responses, samples size, study dropouts, statistical analyses, data management, and safety monitoring. Delphi and nominal group techniques were used.

RESULTS

Briefly, patients with diffuse cutaneous SSc of less than 24 months' duration should be included because they are at greatest risk for the development of severe organ damage and death. Patients should be excluded if they have other connective tissue diseases, SSc-like illnesses related to exposures or ingestions, severe existing internal organ damage, an unacceptable risk of side effects, or concurrent therapies that might independently influence the outcome. Randomized, double-blind, placebo-controlled trials are preferred. The treatment and followup period must be long enough to permit observation of any disease modification, which is likely to require 18-36 months, unless an extraordinarily effective therapy is identified. Responses selected should be quantitative, consistently and accurately reflect activity of SSc in major target organs (not solely the skin), be sensitive to change, and be standardized, with limited variability. An example of a set of responses is given. Surrogate responses are desirable, but none have been validated as correlating with organ damage.

CONCLUSION

Guidelines have been established for trials of disease-modifying interventions in SSc. These guidelines will need to be altered as additional information becomes available. Any given protocol will be individualized based on the nature of the intervention and objectives of the study. Nonetheless, each study team should develop a protocol that meets the spirit of these guidelines.

Outcome measurement in scleroderma clinical trials

Clinical trials in scleroderma were reviewed to assess the clinimetric properties of frequently used outcome measures. Twenty-seven controlled intervention studies were found in the English literature; nine demonstrated effective therapy. The outcome measures used included skin involvement, functional status, physical performance (grip strength, oral aperture), and internal organ involvement (pulmonary, gastrointestinal, renal, and cardiac). Very few outcome measures detected between- or within-group differences even when an active drug was compared with a placebo. Skin measures were found to yield statistical differences in seven studies, patient global assessment in three, and physician global assessments in four. Internal organ measures detected differences between groups only rarely; the pulmonary diffusing capacity was statistically different twice. Physical performance measures (eg, grip strength and oral aperture) never yielded statistical differences, and in only one of five trials did a functional assessment detect statistical differences. To show drug efficacy in future trials in scleroderma, better outcome measures need to be developed and a consensus obtained on which outcomes to use so that potentially effective therapies can be tested in a standardized fashion against a placebo or current therapy. Currently, because of a lack of clinimetric data on outcome measures, therapeutic inefficacy cannot be differentiated from a lack of sensitivity in the outcome measures used. In the future, outcome measures should be chosen on the basis of the adequacy of their reliability, construct, and content validity and be sensitive to change. Ideally, outcome measures also should have criterion validity, ie, show a strong association between the measure (such as a skin score) and an irrefutable gold standard (such as skin pathology).