Clinical outcome measures and rating scales in multiple sclerosis trials

Assessment of disability and disease burden in neuromyelitis optica spectrum disorders in the CIRCLES Cohort

Neuromyelitis optica spectrum disorders (NMOSD) comprise autoimmune diseases imposing substantial disability. We compared an NMOSD-targeted disability assessment of mobility, vision, and self-care domains (individually and composite) with the multiple sclerosis-targeted Expanded Disability Status Scale (EDSS) to assess NMOSD disease burden. An overall cohort (n = 505) and a subset of these patients with an enriched dataset (n = 198) were analyzed from the CIRCLES longitudinal, observational database of patients with AQP4-IgG-seropositive or -seronegative NMOSD in North America. Multinomial modeling was used to identify temporal correlates of disability improvement, stability, and worsening. Prior on-study relapse correlated with worsening mobility (OR, 3.08; 95% CI: 1.61-5.90), vision (OR, 3.99; 95% CI: 2.03-7.86), self-care disability (OR, 1.90; 95% CI: 1.07-3.38), and mean composite index disability (OR, 4.20; 95% CI: 1.71-10.34). Higher vision disability was associated with Black race, shorter time on-study, and AQP4-IgG-seropositive status in patients ≥ 18 years (p < 0.05). Disease onset phenotype and sex correlated with pain interference (p < 0.05). These correlates of NMOSD disability were undetected by EDSS. The CIRCLES real-world experience supports the need for NMOSD-specific disability assessment to improve recognition of disease burden, facilitate proactive clinical management, offer insights into resilience, and inform clinical trial design.

Randomized, double-blind, placebo-controlled study of subcutaneous interferon beta-Ia in relapsing-remitting multiple sclerosis: a categorical disability trend analysis

The treatment effects of recent immunomodulatory therapies on disease progression in relapsing-remitting multiple sclerosis (MS) have been mostly established from 'confirmed progression' endpoints. However, the reliability of this outcome measure is poor and a significant proportion of patients may be erroneously classified. We previously proposed the area under disability/time curves to quantify in-trial disability changes, but although these have advantages, they lack information on the direction of change. We have therefore performed disease trend analyses and categorical classifications using serial Expanded Disability Status Scale (EDSS) scores from the 533 complete datasets in a double-blind, randomized, placebo-controlled, phase III trial of subcutaneous interferon β-1a (IFNβ-1a) (PRISMS study). We found significant treatment benefits for IFNβ-1a on in-trial disability course (P=0.002). Therapeutic advantages remained when relapse-related assessments were excluded (P=0.018). Post hoc analyses demonstrated that IFNβ-la was mainly effective in both increasing the proportion of patients with a 'stable' course and reducing those with prolonged, disabling deteriorations. Baseline disease duration and EDSS levels, but not MRI lesion load, predicted the subsequent disability trends. Mean 'numbers needed to treat' (NNTs) to obtain preferred disability courses were reduced in patients with shorter disease duration. These results have important implications for the targeting of immunomodulatory therapies in MS. Multiple Sclerosis (2002) 8, 10-14

Predictors of Fatigue Impact in Persons With Long-Standing Multiple Sclerosis

BACKGROUND

Fatigue is a common experience among persons diagnosed with multiple sclerosis (MS). Fatigue negatively influences quality of life, interferes with activities of daily living, and impairs the ability to maintain gainful employment. Mechanisms underlying the pathophysiologic determinants of fatigue in MS are poorly understood, and effective treatments to manage fatigue present a challenge. Although the use of pharmacologic therapies is recommended to treat symptomatic fatigue, undertreatment of fatigue is common. Better long-term management and symptomatic relief may be provided by the use of nonpharmacologic treatments such as increased physical activity, energy conservation, and cognitive behavioral therapy.

METHODS

The purpose of this study was to explore the physical, cognitive, and psychosocial dimensions of fatigue impact among persons with long-standing MS-defined here as having been diagnosed with MS for 17 years or more. A sample of 331 participants with MS completed surveys measuring fatigue impact, MS-related functional limitation, depressive symptoms, barriers to health promotion, personal resources, and health promoting behaviors.

RESULTS

MS-related functional limitation and depressive symptoms were the strongest predictors of fatigue impact. MS-related functional limitation explained the greatest amount of variance in models predicting physical and psychosocial fatigue impact, whereas depressive symptoms explained the most variance in models predicting total and cognitive fatigue impact. Barriers to health promotion explained the least amount of variance among the models. Personal resources and health promoting behaviors were not significant predictors of fatigue impact in this study.

CONCLUSION

Interventions aimed at reducing MS-related functional limitations, depressive symptoms, and barriers to health promotion may have beneficial influences on fatigue impact, whereas actions designed to promote personal resource adequacy as well as engagement in health promoting behaviors may not translate into improvements in fatigue impact in persons with MS.

How similar are commonly combined criteria for EDSS progression in multiple sclerosis?

Introduction Measuring disease progression is an important aspect of multiple sclerosis (MS) clinical trials. Commonly applied disability endpoints include time to clinically meaningful Expanded Disability Status Scale (EDSS) change, or the number of patients in whom such a change has occurred. Typically, clinically meaningful EDSS change has been defined as a change of 1.0 point on Kurtzke’s EDSS in patients with an entry EDSS score of 5.5 or lower, or 0.5 point in patients with a higher EDSS score. Our goal was to evaluate whether these changes can be considered as similar. Therefore, we compared EDSS changes to corresponding changes in the Guy’s Neurological Disability Scale (GNDS), which is a measure of patient perceived disability, and the Multiple Sclerosis Functional Composite (MSFC), which is an examination-based quantitative scoring of neurological impairment.

Methods From a large longitudinal database, we selected two groups of patients with a clinically meaningful change in EDSS score according to the usual criteria: patients with EDSS change]/1.0 for baseline EDSS 5/5.5 and patients with EDSS change]/0.5 for baseline EDSS]/6.0. We compared changes in GNDS sum score and in MSFC score between both groups.

Results In the group with baseline EDSS]/6.0, GNDS and MSFC changes were higher than in patients with baseline EDSS 5/5.5. The difference in change was 1.00 (95% confidence interval (CI): / 0.35 to 2.36) for the GNDS and 0.412 (95% CI: 0.300-0.525) for the MSFC.

Conclusion Our results indicate that a 0.5 point EDSS change in patients with baseline EDSS / 6.0 cannot be considered equal to a 1.0 point change in patients with baseline EDSS 5/5.5.

Outcome expectations and physical activity in persons with longstanding multiple sclerosis

Research suggests that persons with multiple sclerosis (MS) are much less physically active than the general population and that increased physical activity in persons with MS is associated with numerous benefits such as improvements in fatigue, mobility, and quality of life (). Potentially modifiable theory-based determinants of physical activity behavior need to be identified so that researchers may study their effectiveness in randomized clinical trials and clinicians may integrate them into practice to promote physical activity in this population. The purpose of this study was to explore the multidimensional (physical, social, and self-evaluative) outcome expectations for physical activity among persons with longstanding MS. A sample of 369 participants diagnosed with MS for more than 15 years completed surveys to measure multidimensional outcome expectations for exercise, MS functional limitations, and physical activity using two different instruments: one measuring physical activity engagement and the other measuring physical activity capability. Results indicated that MS functional limitation was the strongest predictor of both physical activity engagement and physical activity capability. Physical and social outcome expectations contributed to the model explaining 12% of the variation in physical activity engagement, whereas none of the outcome expectancy dimensions (physical, social, or self-evaluative) contributed to the model explaining variation in physical activity capability. Although analyses of cross-sectional data do not infer causation, these findings suggest that positive physical and social outcome expectations for physical activity are associated with engagement in physical activity as well as being potential sources of motivation for increasing physical activity behavior in individuals living with longstanding MS.

Self-report versus performance measure in gauging level of function with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a debilitating, progressive disease with no known cure. Symptoms vary widely for persons with MS and measuring levels of fine motor, gross motor and cognitive function is a large part of assessing disease progression in both clinical and research settings. While self-report measures of function have advantages in cost and ease of administration, questions remain about the accuracy of such measures and the relationship of self-reports of functioning to performance measures of function.

OBJECTIVE

The purpose of this study was to compare scores on a self-report measure of functional limitations with MS with a performance-based measure at five different time points.

METHODS

Sixty participants in an ongoing longitudinal study completed two measures of function annually over a five-year period - the self-report Incapacity Status Scale and the MS Functional Composite (MSFC), a performance test. Pearson correlations were used to explore the association of self-report and performance scores.

RESULTS

There were moderate to strong correlations among the ISS total (r = -.53 to -.63, p < .01) and subscale scores of gross (r = .79 to .87; p < .01)) and fine (r = .47 to .69; p < .01) motor function and the corresponding MSFC performance measure. The pattern of change over time in most scores on self-report and performance measures was similar.

CONCLUSION

Findings suggest that the self-report measure examined here, which has advantages in terms of feasibility of administration and patient burden, does relate to performance measurement, particularly in the area of gross motor function, but it may not adequately reflect cognitive function.

Temporal and spatial evolution of grey matter atrophy in primary progressive multiple sclerosis

Grey matter (GM) atrophy occurs early in primary progressive MS (PPMS), but it is unknown whether its progression involves different brain regions at different rates, as is seen in other neurodegenerative diseases. We aimed to investigate the temporal and regional evolution of GM volume loss over 5 years and its relationship with disability progression in early PPMS.

We studied 36 patients with PPMS within five years from onset and 19 age and gender-matched healthy controls with clinical and imaging assessments at study entry and yearly for 3 years and then at 5 years. Patients were scored on the expanded disability status scale (EDSS) and MS Functional Composite (MSFC) at each time-point. An unbiased longitudinal voxel-based morphometry approach, based on high-dimensional spatial alignment within-subject, was applied to the serial imaging data. The rate of local (voxel-wise) volume change per year was compared between groups and its relationship with clinical outcomes was assessed.

Patients deteriorated significantly during the five years follow-up. Patients showed a greater decline of GM volume (p < 0.05, FWE-corrected) bilaterally in the cingulate cortex, thalamus, putamen, precentral gyrus, insula and cerebellum when compared to healthy controls over five years, although the rate of volume loss varied across the brain, and was the fastest in the cingulate cortex. Significant (p < 0.05, FWE-corrected) volume loss was detected in the left insula, left precuneus, and right cingulate cortex in patients at three years, as compared to baseline, whilst the bilateral putamen and the left superior temporal gyrus showed volume loss at five years. In patients, there was a relationship between a higher rate of volume loss in the bilateral cingulate cortex and greater clinical disability, as measured by the MSFC, at five years (Pearson's r = 0.49, p = 0.003).

Longitudinal VBM demonstrated that the progression of GM atrophy in PPMS occurs at different rates in different regions across the brain. The involvement of the cingulate cortex occurs early in the disease course, continues at a steady rate throughout the follow-up period and is associated with patient outcome. These findings provide new insights into the characteristics of GM atrophy across the brain in MS, and have potential consequences for the selection of brain atrophy as an outcome measure in neuroprotective clinical trials.

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Longitudinal VBM and TBM can be used in longitudinal studies in multiple sclerosis.

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GM loss is a dynamic process in primary progressive multiple sclerosis.

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The highest rate of GM reduction is seen in the cingulate gyri.

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GM atrophy may be used as an outcome measure for neuroprotective clinical trials.

A novel approach with "skeletonised MTR" measures tract-specific microstructural changes in early primary-progressive MS

We combined tract-based spatial statistics (TBSS) and magnetization transfer (MT) imaging to assess white matter (WM) tract-specific short-term changes in early primary-progressive multiple sclerosis (PPMS) and their relationships with clinical progression. Twenty-one PPMS patients within 5 years from onset underwent MT and diffusion tensor imaging (DTI) at baseline and after 12 months. Patients' disability was assessed. DTI data were processed to compute fractional anisotropy (FA) and to generate a common WM "skeleton," which represents the tracts that are "common" to all subjects using TBSS. The MT ratio (MTR) was computed from MT data and co-registered with the DTI. The skeletonization procedure derived for FA was applied to each subject's MTR image to obtain a "skeletonised" MTR map for every subject. Permutation tests were used to assess (i) changes in FA, principal diffusivities, and MTR over the follow-up, and (ii) associations between changes in imaging parameters and changes in disability. Patients showed significant decreases in MTR over one year in the corpus callosum (CC), bilateral corticospinal tract (CST), thalamic radiations, and superior and inferior longitudinal fasciculi. These changes were located both within lesions and the normal-appearing WM. No significant longitudinal change in skeletonised FA was found, but radial diffusivity (RD) significantly increased in several regions, including the CST bilaterally and the right inferior longitudinal fasciculus. MTR decreases, RD increases, and axial diffusivity decreases in the CC and CST correlated with a deterioration in the upper limb function. We detected tract-specific multimodal imaging changes that reflect the accrual of microstructural damage and possibly contribute to clinical impairment in PPMS. We propose a novel methodology that can be extended to other diseases to map cross-subject and tract-specific changes in MTR.

Corpus callosum damage predicts disability progression and cognitive dysfunction in primary-progressive MS after five years

We aim to identify specific areas of white matter (WM) and grey matter (GM), which predict disability progression and cognitive dysfunction after five years in patients with primary-progressive multiple sclerosis (PPMS). Thirty-two patients with early PPMS were assessed at baseline and after five years on the Expanded Disability Status Scale (EDSS), and EDSS step-changes were calculated. At year five, a subgroup of 25 patients and 31 healthy controls underwent a neuropsychological assessment. Baseline imaging consisted of dual-echo (proton density and T2-weighted), T1-weighted volumetric, and diffusion tensor imaging. Fractional anisotropy (FA) maps were created, and fed into tract-based spatial statistics. To compensate for the potential bias introduced by WM lesions, the T1 volumes underwent a lesion-filling procedure before entering a voxel-based morphometry protocol. To investigate whether FA and GM volume predicted EDSS step-changes over five years and neuropsychological tests scores at five years, voxelwise linear regression analyses were performed. Lower FA in the splenium of the corpus callosum (CC) predicted a greater progression of disability over the follow-up. Lower FA along the entire CC predicted worse verbal memory, attention and speed of information processing, and executive function at five years. GM baseline volume did not predict any clinical variable. Our findings highlight the importance of damage to the interhemispheric callosal pathways in determining physical and cognitive disability in PPMS. Disruption of these pathways, which interconnect motor and cognitive networks between the two hemispheres, may result in a disconnection syndrome that contributes to long-term physical and cognitive disability.

Structural equation modeling of disability in women with fibromyalgia or multiple sclerosis

Structural equation modeling (SEM), a popular statistical technique for analysis of multivariate data in the social sciences, is increasingly being used in the behavioral and clinical sciences. SEM is appropriate for posing complex models that evaluate the direct and indirect influence of several variables on one or more outcome variables. A biosocial model of disability, the Disablement Process Model, lends itself to evaluation by SEM. Using SEM, this study examined predictors of disability (Age, Education, Duration of Illness, and Economic Adequacy Functional Limitations, Depressive Symptoms, and Social Support) separately in women with multiple sclerosis (MS) and women with fibromyalgia syndrome (FMS) and compared the respective models across groups. Data were analyzed with Analysis of Moment Structures (Amos) 7.0. Problems identified in initial confirmatory model testing included collateral correlated errors, a negative error variance, and poor performance of the disability indicators. After specifying well-fitting confirmatory models for each group, a structural model for the larger FMS group was estimated. Model refinement resulted in the reversal of the path between Depressive Symptoms and Social Support. Further model revisions were based on comparative fit statistics and theoretical logic. The structural model developed from the FMS sample required minimal changes to fit the MS sample. The multisample model explained greater variance in disability in women with FMS than in women with MS. Social support and depressive symptoms mediated the effect of functional limitations on disability. Interventions that target modifiable characteristics, such as depression and social support, may improve outcomes such as disability.

Natalizumab update

PURPOSE

The pharmacology, pharmacokinetics, indications, clinical efficacy, adverse effects, drug interactions, and dosage and administration of natalizumab are reviewed.

SUMMARY

Natalizumab, the first commercially available selective adhesion-molecule inhibitor, is approved as monotherapy for the treatment of patients with relapsing forms of multiple sclerosis (MS). Natalizumab exerts its immunologic effects by targeting the alpha4 integrin receptor, the site responsible for the migration of leukocytes from the blood into inflamed tissues. Because of the increased risk of progressive multifocal leukoencephalopathy (PML), natalizumab is generally recommended for patients who have had an inadequate response to or are intolerant of alternative MS therapies. Data evaluating the efficacy and safety of natalizumab for the treatment of MS are available from published Phase II and III trials. The most common adverse effects reported include headache, fatigue, urinary-tract infection, depression, arthralgia, and lower respiratory-tract infection. The recommended dosage of natalizumab for the treatment of relapsing forms of MS is 300 mg administered by i.v. infusion over one hour once every four weeks. Natalizumab is available only through a risk-minimization program run by the manufacturer.

CONCLUSION

Natalizumab offers an effective treatment option for patients with MS who have had an inadequate response to or are intolerant of alternative MS therapies. Because of its potential to increase the risk of PML, the risks and benefits should be carefully weighed before initiating natalizumab therapy in patients with MS. Natalizumab should not be used to treat Crohn's disease or any other unapproved indication until more postmarketing safety data are available.

Center of pressure measures during standing tasks in minimally impaired persons with multiple sclerosis

BACKGROUND AND PURPOSE

Balance impairments are common in persons with multiple sclerosis (MS), but clinical balance tests may not detect subtle deficits in adults with MS who are not yet experiencing functional limitations or disability. The purpose of this study was to determine if center of pressure (COP) displacement during standing tasks could be a useful performance-based evaluative measure for adults with MS who have minimal or no balance deficits on clinical examination using the Berg Balance Scale (BBS).

SUBJECTS AND METHODS

Twenty-one adults with MS were compared with 21 age- and gendermatched healthy adults. Subjects with MS were tested with the BBS, Mini-mental State Exam, Expanded Disability Status Scale (EDSS), and Multiple Sclerosis Functional Composite (MSFC). They also performed voluntary leaning and reaching movements while kinematic and kinetic data were collected. Control subjects performed the same tasks with the exception of the EDSS and MSFC.

RESULTS

COP displacement during reaching and leaning was less in adults with MS when compared to control subjects. There were no differences in anthropometric, kinematic, or foot position variables that could account for this difference. Furthermore, there was no difference between groups when COP displacement during reaching was expressed as a percentage of the maximum COP displacement during leaning.

DISCUSSION AND CONCLUSION

COP measures show clear differences when comparing healthy adults with minimally impaired adults with MS. The lack of between-group differences when COP displacement during reaching was expressed as a percentage of the maximum COP displacement during leaning suggests that the subjects with MS adopt a reaching strategy that allows them to stay within their reduced limits of stability. COP measures during standing tasks appear well-suited to quantifying changes in postural control over time or in response to intervention for minimally impaired persons with MS.

Multiple sclerosis: severity and progression rate in African Americans compared with whites

OBJECTIVE

Although epidemiology indicates that multiple sclerosis is more common among whites than African Americans, the course of disease may be more aggressive among African Americans. This study examines disease course in a large multiple sclerosis clinic population.

DESIGN

A case-controlled, retrospective record review compared the severity of multiple sclerosis for African Americans and for whites. Because the baseline demographics of the two groups differed, we performed analyses of multiple subgroups in an attempt to control for various characteristics.

RESULTS

Consistent evidence of more disability in African Americans compared with whites was found, although subgroups were often too small to establish statistical significance. African Americans had a higher mean Expanded Disability Status Scale score than whites in a subgroup selected to minimize differences in access to care and disease perceptions. African Americans reported limb weakness as a presenting symptom of multiple sclerosis more frequently than did whites. When patients were followed at our multiple sclerosis center, rates of disease progression were nearly identical.

CONCLUSIONS

More African Americans than whites experience pyramidal system involvement early in multiple sclerosis, leading to greater disability as measured by the ambulation-sensitive Expanded Disability Status Scale. Once patients have moderate difficulty walking, the rate of progression is the same for both groups, albeit occurring at a later age for whites than for African Americans.

Providing pharmaceutical care to the multiple sclerosis patient

OBJECTIVE

To review the pathophysiology, symptoms, and treatment of multiple sclerosis (MS).

DATA SOURCES

Recently published clinical literature identified through review of articles abstracted at MEDLINE. Search terms included multiple sclerosis, interferon beta, glatiramer acetate, mitoxantrone, treatment, symptoms, steroids, etiology, and neutralizing antibodies.

STUDY SELECTION

Performed manually by the authors.

DATA EXTRACTION

Performed manually by the authors.

DATA SYNTHESIS

MS is a chronic disease of the central nervous system that most often strikes patients in their early 30s. Noticeable geographic, ethnic, racial, and sex differences in incidence remain unexplained. Diagnosis relies heavily on the presence of neurologic signs and symptoms, and magnetic resonance imaging of the brain is increasingly useful. Treatment with steroids, interferon beta-1b (Betaseron-Berlex) and interferon beta-1a (Avonex-Biogen; Rebif-Serono), and glatiramer acetate (Copaxone-Teva) can produce periods of remission in patients with MS. Management of adverse medication effects and disease-related symptoms of fatigue, pain, and bladder dysfunction is important in these patients.

CONCLUSION

MS is currently incurable but largely treatable. Research has produced promising new medications, and investigational therapies hold promise for better treatment of this debilitating condition.

Randomized, double-blind, placebo-controlled study of subcutaneous interferon beta-1a in relapsing-remitting multiple sclerosis: a categorical disability trend analysis

The treatment effects of recent immunomodulatory therapies on disease progression in relapsing-remitting multiple sclerosis (MS) have been mostly established from 'confirmed progression' endpoints. However, the reliability of this outcome measure is poor and a significant proportion of patients may be erroneously classified. We previously proposed the area under disability/time curves to quantify in-trial disability changes, but although these have advantages, they lack information on the direction of change. We have therefore performed disease trend analyses and categorical classifications using serial Expanded Disability Status Scale (EDSS) scores from the 533 complete datasets in a double-blind, randomized, placebo-controlled, phase III trial of subcutaneous interferon beta-1a (IFNbeta-1a) (PRISMS study). We found significant treatment benefits for IFNbeta-1a on in-trial disability course (P=0.002). Therapeutic advantages remained when relapse-related assessments were excluded (P=0.018). Post hoc analyses demonstrated that IFNbeta-1a was mainly effective in both increasing the proportion of patients with a 'stable' course and reducing those with prolonged, disabling deteriorations. Baseline disease duration and EDSS levels, but not MRI lesion load, predicted the subsequent disability trends. Mean 'numbers needed to treat' (NNTs) to obtain preferred disability courses were reduced in patients with shorter disease duration. These results have important implications for the targeting of immunomodulatory therapies in MS.

Identifying disease modifying genes in multiple sclerosis

Evidence is mounting that genetic variation influences not only susceptibility to multiple sclerosis (MS), but also its course and severity. Identification of disease modifying genes, however, poses unique challenges, especially on how to classify the course and outcome of the disease in ways that may be relevant to analysis of biological factors that might be influenced by genes. The power of the statistical approaches to detect small effects of individual genes in complex disorders such as MS is problematic, and approaches to estimate power must be appropriate for the data. Nonetheless, using contemporary schemes of classification, genetic variants that influence disease course have been found; in fact, a small number have been confirmed to influence disease course in two or more independent studies. This review addresses strategies relevant to identification of disease modifying genes in MS, and summarizes and critically evaluates the current state of knowledge in this area.

Clinical outcome measures for research in multiple sclerosis

The development of new and more sensitive clinical outcome measures for research in multiple sclerosis (MS) has been fueled by the development of effective therapies. As such, active arm comparison studies that require more sensitive clinical outcome measures are now commonplace. The Kurtzke Expanded Disability Status Scale (EDSS), the most widely used measure of neurologic impairment in MS, is particularly designed for classifying patients with respect to disease severity but has been criticized for its noninterval scaling, emphasis on ambulation status, relatively reduced sensitivity in the mid and upper ranges of scores, and absence of adequate cognitive and visual components. In response to perceived difficulties with the EDSS, the National Multiple Sclerosis Society Clinical Outcomes Assessment Task Force has developed the Multiple Sclerosis Functional Composite (MSFC). The MSFC includes three components that yield objective and quantitative results: 1) the timed 25-ft walk, 2) the nine-hole peg test, and 3) the 3-second paced auditory serial addition test. This scale has the advantages of continuous scoring with a composite Z score, standardized protocols, and high degrees of reliability and validity. Candidate visual function outcome measures for the MSFC, including the low-contrast Sloan letter chart, are currently under investigation. In addition to measures of neurologic impairment, health-related quality of life (HRQOL) measures have gained increasing importance as clinical trial outcome measures. The MS Quality of Life Inventory, a disease-specific HRQOL measure, has been developed to capture self-reported neurologic dysfunction and the impact of MS upon activities of daily living. MS clinical trials of the future, particularly active-arm comparison studies, will require more sensitive clinical outcome measures such as the MSFC. Measures of visual function and HRQOL should also be incorporated to capture the broad scope of neurologic impairment and disability in MS populations.

Self-administered Expanded Disability Status Scale with functional system scores correlates well with a physician-administered test

BACKGROUND

Patient-administered measures are needed to assess disability cost-effectively in large epidemiological studies.

SETTING

An outpatient clinic in a large multiple sclerosis center.

METHODS

A self-administered EDSS questionnaire was developed (EDSS-S). Consecutive patients with clinically definite multiple sclerosis completed the EDSS-S (n=95). During the same visit, a physician completed an EDSS (EDSS-P). Scores below 4.0 were determined using functional system (FS) scores. Scores above 4.0 were calculated by two methods, using gait alone and using gait and functional system scores combined.

RESULTS

EDSS-P scores ranged from 0-9.5 (mean 5.1, median 5.0, 78% female, age 17-78, mean age 45). Mean EDSS-P, EDSS-S and intraclass correlation coefficients of agreement were: EDSS using ambulation alone (4.6, 5.1, 0.89), EDSS using ambulation and FS scores (4.6, 5.3, 0.87), bowel/bladder FS scores (1.6, 1.7, 0.79), pyramidal FS scores (2.1, 2.4, 0.67), sensory FS scores (1.6, 2.1, 0.60), cerebellar FS scores (1.1, 1.6, 0.55), brainstem FS scores (0.5, 1.2, 0.45), vision FS scores (1.9, 1.3, 0.38), cerebral FS scores (0.6, 2.3, 0.27).

CONCLUSIONS

Very good correlation was seen between patient and physician scores for EDSS and the bowel/bladder FS score. Four other FS scores correlated moderately. In general, patients scored themselves more disabled than physicians.

Benefits of glatiramer acetate on disability in relapsing-remitting multiple sclerosis. An analysis by area under disability/time curves. The Copolymer 1 Multiple Sclerosis Study Group

New immunomodulatory therapies for relapsing-remitting multiple sclerosis (RRMS) have well-documented effects in reducing relapses, but it has been difficult to demonstrate their benefits on disability in relatively short treatment trials. Commonly utilised disability outcome measures are problematic both in usefulness and clinical interpretation when applied to MS subjects with fluctuating and variable disease courses. An alternative technique is to use the summary measure 'area under the disability/time curve' (AUC) to index the total in-trial morbidity experienced by patients. In this study, we applied AUC analyses to the serial Expanded Disability Status Scale (EDSS) scores from the U.S. multicentre, Phase III, two-year core study of glatiramer acetate in 251 RRMS patients. When all available EDSS evaluations were analysed with AUC(CHANGE) ('combined data', including relapse-related assessments), active treatment was significantly superior to placebo (P=0.018). The benefits of glatiramer acetate persisted when transient relapse effects were reduced by using 'scheduled visit data' only (P=0.021). With the more conservative AUC(SUM) measure, significant active treatment effects remained (P=0.029 and 0.046, for both 'combined' and 'scheduled visit' data, respectively). Subgroup calculations performed with baseline disability stratified at EDSS 3.5 also showed benefits of treatment over placebo, but statistical significance was not reached. This analysis of data from a Phase III treatment trial illustrates the AUC summary measure technique and provides further evidence of the efficacy of glatiramer acetate in RRMS.

Disability outcome measures in therapeutic trials of relapsing-remitting multiple sclerosis: effects of heterogeneity of disease course in placebo cohorts

OBJECTIVES

Recent phase III clinical trials of immunomodulatory therapies in relapsing-remitting multiple sclerosis have shown significant benefits of active treatment on relapse related end points, but effects on disability outcomes have been inconsistent. These apparent discrepancies could be due to differences in the clinical end points employed, the behaviour of placebo cohorts, or both.

METHODS

Disability data from the placebo cohorts of two large phase III studies, the United States glatiramer acetate trial (Copolymer 1 Multiple Sclerosis Study Group) and the multinational interferon beta-1a trial (PRISMS Study Group) were combined and masked (n = 313). Two groups of disability outcome measures were assessed. Firstly, measures of disability change (2 year EDSS difference and area under the EDSS/time curve, AUC) were calculated. Secondly, conventional disease progression end points ("confirmed progression" and "worsening to EDSS 6.0") were evaluated by using Kaplan-Meier analysis and compared with a categorical classification based on EDSS trends.

RESULTS

The average increase in disability for the entire cohort as assessed by mean 2 year EDSS change (<0.5 EDSS point) or mean AUC (+0.57 EDSS-years) was small. For the "confirmed progression" end points, increasing the stringency of the definition lowered their incidence (from 32% with 1.0 point at 3 months, to 9% with 2.0 points at 6 months), but did not improve the positive predictive accuracy for "sustained progression" maintained to the end of the study. The error rate for this outcome was about 50%. Worsening to EDSS 6.0 was a more reliable end point, but had even lower sensitivity (incidence <10%). EDSS trend analysis showed markedly heterogeneous disease courses, which were then categorised into "stable" (26%), "relapsing-remitting" (59%), and "progressive" (15%) courses. Patients with the last course had deteriorated considerably by the end of 2 years (mean worsening of 2.0 EDSS points).

CONCLUSION

In relapsing-remitting multiple sclerosis treatment trials, the conventional measure of mean EDSS change has low sensitivity, whereas the widely applied confirmed progression end points have high error rates regardless of their definition stringency. Alternative methods with better data utilisation include AUC summary measures and categorical disease trend analysis. The heterogeneity of disability outcomes in short trials, combined with unreliable clinical end points, diminishes the credibility of therapeutic claims aimed at reducing irreversible neurological deficits. The behaviour of patients treated with placebo should be carefully analysed before conclusions are drawn on the efficacy of putative treatments.

Randomised, double blind, placebo controlled study of interferon beta-1a in relapsing-remitting multiple sclerosis analysed by area under disability/time curves

OBJECTIVES

The commonly employed outcome measures on disability and relapse rates in treatment trials of relapsing-remitting multiple sclerosis have well demonstrated sensitivity to treatment effects, but their clinical interpretation is problematic. An alternative method of analysis, which is more clinically meaningful and statistically appropriate to a condition with a fluctuating disease course, uses the summary measure statistic "area under the disability/time curve (AUC)", to estimate each patient's total in trial morbidity experience.

METHODS

The AUC technique was applied in an intention to treat analysis of serial disability data derived from the expanded disability status scale (EDSS), the Scripps neurologic rating scale (SNRS), and the ambulation index (AI), collected during a double blind, randomised, placebo controlled, phase III trial of subcutaneous interferon beta-1a (INFbeta-1a) in relapsing-remitting multiple sclerosis (PRISMS Study). The results were compared with the often quoted "conventional" end point of mean change in rating scores from baseline to trial completion. Analyses were also carried out on subgroups with entry EDSS stratified above and below 3.5.

RESULTS

EDSS data analysed by AUC normalised to baseline scores disclosed that both doses of IFNbeta-1a (22 or 44 microg) were superior to placebo (p= 0.008 and 0.013, respectively). In addition, the high dose (44 microg) was more beneficial than placebo using SNRS (p= 0.038) and AI data (p= 0.039). AUC analysis of SNRS scores also showed that for patients with baseline EDSS>3.5, the 44 microg (but not the 22 microg) dose was more advantageous than placebo (p=0.028).

CONCLUSIONS

Summary measure analysis using the AUC of serial disability/time plots, confirms and extends the results of conventional end point analysis of disability from the PRISMS Study data. AUC evaluations show that high dose INFbeta-1a (44 microg three times weekly) was beneficial on all of the clinical rating scale scores used in this study. This method provides a statistically powerful and clinically meaningful assessment of treatment effects on in trial disability in patients with multiple sclerosis with fluctuating and highly heterogeneous disease courses.

The natural history of multiple sclerosis: implications for trial design

The understanding of the natural history of multiple sclerosis has many implications for the design and interpretation of randomized controlled trials. Selection criteria, patient stratification, outcome measurements, and definitions of treatment failure can influence randomized controlled trial results and limit comparisons among trials. The focus of future studies should shift from short-term determinations of efficacy to definitive evaluations of long-term effectiveness. This will require novel investigative strategies such as the use of historic controls derived from natural history studies.