Design strategies in multiple sclerosis clinical trials. The Cyclosporine Multiple Sclerosis Study Group

The impact of relapse definition and measures of durability on MS clinical trial outcomes

BACKGROUND

Definitions of trial measures are consequential to accurately capturing outcomes and cross-trial comparability, particularly for derivative measures.

OBJECTIVE

Using CombiRx, examine the impact of relapse definition on endpoints and evaluate the durability of progression measures in Relapsing Remitting Multiple Sclerosis (RRMS).

METHODS

CombiRx relapse types were distinguished by the presence or timing of Expanded Disability Status Scale (EDSS) increase. Using the broadest definition of relapse, progression endpoints were assessed in patients without relapses on trial. Durability compared EDSS at study end and time of worsening.

RESULTS

Broadening relapse definition to the most inclusive definition increased annualized relapse rate (ARR) threefold in all arms and decreased progression independent of relapse activity (PIRA), defined as 6-month confirmed disability worsening (6M CDW) without relapse, by 44%. Neither PIRA nor PIA (progression independent of any inflammatory activity) guaranteed durable worsening, with 43% and 40%, respectively, improving by end of study. Multivariate analysis showed two CDW events, not relapse, predicted durability among patients meeting 6M CDW.

CONCLUSIONS

The stringency of relapse definition impacted absolute ARR and composite endpoints in RRMS. Despite the most generous relapse definition, 43% of patients meeting PIRA on trial did not have durable worsening suggesting that relapse definition and durability should be considered to avoid overestimating progression in RRMS trials.

Subcortical volumes as early predictors of fatigue in multiple sclerosis

OBJECTIVE

Fatigue is a frequent and severe symptom in multiple sclerosis (MS), but its pathophysiological origin remains incompletely understood. We aimed to examine the predictive value of subcortical gray matter volumes for fatigue severity at disease onset and after four years by applying structural equation modeling (SEM).

METHODS

This multi-center cohort study included 601 treatment-naive MS patients after the first demyelinating event. All patients underwent a standardized 3T MRI protocol. A subgroup of 230 patients with available clinical follow-up data after four years was also analyzed. Associations of subcortical volumes (included into SEM) with MS-related fatigue were studied regarding their predictive value. In addition, subcortical regions that have a central role in the brain network (hubs) were determined through structural covariance network (SCN) analysis.

RESULTS

Predictive causal modeling identified volumes of the caudate (s [standardized path coefficient]=0.763, p=0.003 [left]; s=0.755, p=0.006 [right]), putamen (s=0.614, p=0.002 [left]; s=0.606, p=0.003 [right]) and pallidum (s=0.606, p=0.012 [left]; s=0.606, p=0.012 [right]) as prognostic factors for fatigue severity in the cross-sectional cohort. Moreover, the volume of the pons was additionally predictive for fatigue severity in the longitudinal cohort (s=0.605, p=0.013). In the SCN analysis, network hubs in patients with fatigue worsening were detected in the putamen (p=0.008 [left]; p=0.007 [right]) and pons (p=0.0001).

INTERPRETATION

We unveiled predictive associations of specific subcortical gray matter volumes with fatigue in an early and initially untreated MS cohort. The colocalization of these subcortical structures with network hubs suggests an early role of these brain regions in terms of fatigue evolution. This article is protected by copyright. All rights reserved.

Covarying patterns of white matter lesions and cortical atrophy predict progression in early MS

Objective

We applied longitudinal 3T MRI and advanced computational models in 2 independent cohorts of patients with early MS to investigate how white matter (WM) lesion distribution and cortical atrophy topographically interrelate and affect functional disability.

Methods

Clinical disability was measured using the Expanded Disability Status Scale Score at baseline and at 1-year follow-up in a cohort of 119 patients with early relapsing-remitting MS and in a replication cohort of 81 patients. Covarying patterns of cortical atrophy and baseline lesion distribution were extracted by parallel independent component analysis. Predictive power of covarying patterns for disability progression was tested by receiver operating characteristic analysis at the group level and support vector machine for individual patient outcome.

Results

In the study cohort, we identified 3 distinct distribution types of WM lesions (cerebellar, bihemispheric, and left lateralized) that were associated with characteristic cortical atrophy distributions. The cerebellar and left-lateralized patterns were reproducibly detected in the second cohort. Each of the patterns predicted to different extents, short-term disability progression, whereas the cerebellar pattern was associated with the highest risk of clinical worsening, predicting individual disability progression with an accuracy of 88% (study cohort) and 89% (replication cohort), respectively.

Conclusion

These findings highlight the role of distinct spatial distribution of cortical atrophy and WM lesions predicting disability. The cerebellar involvement is shown as a key determinant of rapid clinical deterioration.

Application of Item Response Theory to Modeling of Expanded Disability Status Scale in Multiple Sclerosis

In this study, we report the development of the first item response theory (IRT) model within a pharmacometrics framework to characterize the disease progression in multiple sclerosis (MS), as measured by Expanded Disability Status Score (EDSS). Data were collected quarterly from a 96-week phase III clinical study by a blinder rater, involving 104,206 item-level observations from 1319 patients with relapsing-remitting MS (RRMS), treated with placebo or cladribine. Observed scores for each EDSS item were modeled describing the probability of a given score as a function of patients' (unobserved) disability using a logistic model. Longitudinal data from placebo arms were used to describe the disease progression over time, and the model was then extended to cladribine arms to characterize the drug effect. Sensitivity with respect to patient disability was calculated as Fisher information for each EDSS item, which were ranked according to the amount of information they contained. The IRT model was able to describe baseline and longitudinal EDSS data on item and total level. The final model suggested that cladribine treatment significantly slows disease-progression rate, with a 20% decrease in disease-progression rate compared to placebo, irrespective of exposure, and effects an additional exposure-dependent reduction in disability progression. Four out of eight items contained 80% of information for the given range of disabilities. This study has illustrated that IRT modeling is specifically suitable for accurate quantification of disease status and description and prediction of disease progression in phase 3 studies on RRMS, by integrating EDSS item-level data in a meaningful manner.

Assessment of definitions of sustained disease progression in relapsing-remitting multiple sclerosis

Sustained progression on the expanded disability status scale (EDSS) is a common outcome measure of disease progression in clinical studies of MS. Unfortunately, this outcome may not accurately measure long-term and irreversible disease progression. To assess the performance of definitions of sustained progression, patients with relapsing-remitting MS (RRMS) or a clinically isolated syndrome with evidence of lesions on a brain MRI were included in our study. Fifteen definitions of sustained progression using both the EDSS and the functional system (FS) scales were investigated. The impact of both relapses and changes in provider on the probability of maintaining progression was also evaluated. Although the provider scoring the EDSS sometimes changed during followup, the provider had access to previous EDSS scores. Between 15.8% and 42.2% of patients experienced sustained progression based on the definitions using EDSS as the outcome, but nearly 50% of these patients failed to maintain sustained progression for the duration of followup. When FS scales were used, progression was most common on the pyramidal and sensory scales. Unfortunately, progression on specific FS scales failed to be more sensitive to irreversible disability. Relapses or changes in provider did not explain the poor performance of the measures. Short-term changes in the EDSS or FS scores may not be an accurate marker of irreversible change in RRMS.

Health-related quality of life as an independent predictor of long-term disability for patients with relapsing-remitting multiple sclerosis

BACKGROUND AND PURPOSE

Predictive factors of long-term disability in patients with relapsing-remitting multiple sclerosis (RR-MS) are well known, but the weight of these factors does not explain the entire change of disability. Few studies have examined the predictive value of quality of life (QoL).

OBJECTIVES

To determine the value of the initial level of QoL to predict changes in the disability status of patients with MS and to determine if specific-MS questionnaires predict more accuracy in these changes than generic questionnaires.

METHODS

DESIGN

multicenter, multi-regional, and longitudinal study. Main inclusion criteria: patients with RR-MS subtype and an Expanded Disability Status Scale (EDSS) score lower than 7.0. Sociodemographic and clinical data were recorded at baseline. Every 6 months up to month 24, QoL (MusiQoL and SF-36) was recorded. At 24 months, individuals were defined into two 'disability change' groups: the worsened and not worsened patients.

RESULTS

Five-hundred and twenty-six patients were enrolled: 386 (83.7%) not worsened and 75 (16.3%) worsened patients at 24 months. The activity of daily living and the relationship with healthcare workers dimensions of MusiQoL questionnaire were independent predictors of change in the EDSS score after 24 months. The physical-functioning dimension of the SF-36 questionnaire predicted independently disability change after 24 months.

CONCLUSIONS

Patient-reported baseline QoL levels provide additional prognostic information on MS disability beyond traditional clinical or sociodemographic factors. These findings reinforce the importance of incorporating a patient's evaluation of their own QoL level during patient monitoring and the assessment of treatment effects.

Magnetisation transfer ratio in the normal appearing white matter predicts progression of disability over 1 year in early primary progressive multiple sclerosis

BACKGROUND

Progression rates in primary progressive multiple sclerosis (PPMS) vary widely and brain magnetisation transfer imaging (MTI) has potential as an early prognostic indicator. We investigated the predictive value of MTI and the longitudinal changes developing over 1 year in early PPMS.

AIMS

To determine (1) whether baseline brain MTI parameters in early PPMS predict clinical changes over 1 year, independent of brain volume and (2) whether a change in magnetisation transfer (MT) parameters occurs over 1 year, independent of atrophy.

METHODS

30 patients with PPMS within 5 years of symptom onset and 15 controls underwent MT and volumetric imaging studies, at baseline and at 1 year. Patients underwent clinical assessment using the Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Functional Composite (MSFC), including the timed walk subtest (TWT). Normalised MT histograms were generated for whole brain, normal appearing brain tissue (NABT) and normal appearing white and grey matter (NAWM and NAGM) segments. Multiple regression analyses were performed to investigate whether baseline MTR parameters predicted clinical change over 1 year, adjusting for baseline brain volume. MTR changes over 1 year were assessed using paired t tests.

RESULTS

In patients, lower baseline NAWM MTR predicted greater deterioration in EDSS and MSFC, particularly in walking ability measured by the TWT, independent of NAWM baseline volume (p = 0.001). NAGM MTR mean (p<0.001), and to a lesser extent NAWM mean (p = 0.011) and lesion MTR (p = 0.03), decreased over 1 year.

CONCLUSIONS

NAWM MTR may provide information on short term clinical prognosis in early PPMS. MTI is sensitive to brain tissue changes over 1 year in early PPMS, which were primarily seen in the NAGM.

Long-term clinical experience with weekly interferon beta-1a in relapsing multiple sclerosis

Post-marketing surveillance studies are needed to assess the long-term safety, compliance and clinical efficacy of interferon beta-1a (IFNbeta-1a) therapy in multiple sclerosis (MS) patients. The goals of this study were to (i) assess the safety, compliance and clinical efficacy of long-term intramuscular (i.m.) IFNbeta-1a therapy in a large cohort of patients, and (ii) suggest possible predictors of therapeutic response. A total of 255 patients were included in the study. Mean time on therapy was 31.7 +/- 19.3 months. Within 3 years, 31% of patients discontinued treatment, mainly for disease activity. No significant sustained blood analysis alteration was observed over time, apart from a decrease of cholesterol levels. After 3 years of treatment, mean Expanded Disability Status Scale (EDSS) scores increased by 0.4 points compared with baseline. The mean annual relapse rate was reduced compared with baseline. Patients with < or = 2 relapses in the previous 2 years and with baseline EDSS scores of < or = 2 had a longer estimated time to first relapse and to progression and first relapse, respectively. These results confirm the safety and suggest a sustained effectiveness of i.m. IFNbeta-1a, extending the reported follow-up period to 6.3 years, and hypothesize the presence of possible predictors of clinical outcome.

Extended observations on MS patients treated with IM interferon-beta1a (Avonex): implications for modern MS trials and therapeutics

Extended observations of the pivotal phase III clinical trial of interferon-beta1a (IFNbeta1a; Avonex, Biogen) in relapsing MS patients revealed that: (1) active treatment significantly slowed the accumulation of physical disability over time, reduced clinical exacerbations and MRI brain lesions; (2) clinical efficacy did not depend on disability endpoints; (3) active treatment benefited multiple MRI measures of brain lesions; (4) cerebral atrophy occurred over 2 years in relatively mildly disabled patients; and (5) Avonex could slow the development of atrophy after the first year of treatment. Data from this study were recently used to design a new outcome measure for MS clinical trials (the Multiple Sclerosis Functional Composite), and was also the basis for two ongoing studies of IFNbeta1a: one in patients with monosymptomatic onset of MS and the other in secondary progressive MS.

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.

Responsiveness of the Scripps neurologic rating scale during a multiple sclerosis clinical trial

OBJECTIVE

The Scripps neurologic rating scale (SNRS) is a summary measure of individual components comprising a neurological examination, designed for use in multiple sclerosis (MS). Our objective is to evaluate the responsiveness of the SNRS, within the context of a 2-year, randomized, double-blind crossover study of the efficacy of cladribine for treatment of secondary progressive MS.

METHODS

Effect sizes were determined for the SNRS and its components, separately for each treatment group (initial placebo, and initial cladribine) over both years of the clinical trial, using a standard random effects model.

RESULTS

Individual components tended to show positive effect sizes (improvement) during periods of active therapy in both treatment groups, and negative effect sizes (deterioration) during periods of no active therapy. Summation indices derived from the individual components of the SNRS seemed somewhat more stable than the individual components. The two components mentation and mood, and bladder, bowel, or sexual dysfunction, were rather unresponsive in our clinical trial.

CONCLUSIONS

Changes in the components of the SNRS over the course of our clinical trial were consistent between the two treatment groups. Most components were moderately responsive; and, the summary SNRS score appropriately summarized the moderate magnitudes of change evinced in the individual components.

Modified total lymphoid irradiation and low dose corticosteroids in progressive multiple sclerosis

In a double-blind prospective randomized trial, we assessed the efficacy and safety of modified total lymphoid irradiation (TLI) plus low dose prednisone (TLI-LDP) as compared to sham TLI plus identical prednisone therapy (sham TLI-LDP) in 46 patients with progressive forms of multiple sclerosis (MS). No significant difference existed between groups at study entry in patient age, sex, duration of MS, or disability status. However, following treatment, significantly fewer TLI patients showed a sustained one point decline in the Expanded Disability Status Scale, the primary study endpoint, as compared to the sham TLI group using the Kaplan-Meier Product-limit survival analysis, (P<0.005). Risk for relapse requiring treatment with intravenous methylprednisolone was reduced by 54% in the TLI-treated group (P<0.05). Significantly fewer TLI-LDP patients had gadolinium enhancing plus new T2-weighted lesions (P=0.018) when compared to the sham group post-treatment. There was also a substantial and significant decrease in blood lymphocytes in the TLI-LDP group when compared to either pretreatment values or to sham TLI-LDP through at least 12 months post-therapy. Side effects secondary to TLI were generally mild and well-tolerated. These results further support the hypothesis that TLI and systemic immunosuppression have a beneficial effect in progressive forms of MS.

Gadolinium enhanced MRI predicts clinical and MRI disease activity in relapsing-remitting multiple sclerosis

The aim of the study was to evaluate the predictive power of baseline gadolinium (Gd) enhanced MRI in relation to subsequent clinical and MRI activity. Sixty eight patients with clinically definite relapsing-remitting multiple sclerosis had a baseline Gd enhanced MRI and were followed up clinically and by monthly Gd enhanced MRI for six months. The occurrence of relapses during the follow up period was predicted by the presence of at least one enhancing lesion on the baseline MRI (P < 0.05). The number and volume of enhancing lesions at baseline were significantly associated with both enhancing lesions observed during the follow up period (P < 0.0001) and the accumulation of abnormality on T2 weighted images (P < 0.0001). Moreover, the presence of three or more enhancing lesions at baseline scan was consistently associated with the development of permanent abnormalities on T2 weighted images six months later. The study suggests that the number and volume of Gd enhancing lesions at a single examination are strong short term predictors of subsequent clinical and MRI activity.

Comparative evaluations of neuroperformance and clinical outcome assessments in chronic progressive multiple sclerosis: I. Reliability, validity and sensitivity to disease progression. Multiple Sclerosis Study Group

There remains controversy regarding the most sensitive and valid outcome assessments to use in multiple sclerosis (MS) clinical trials. A double blind, placebo controlled, parallel group multicenter clinical trial to evaluate the clinical efficacy of cyclosporine A in chronic progressive MS incorporated several major clinical and performance outcome assessment modalities and a large sample size, both of which provide a unique opportunity to explore the relationship among MS disease status and the various outcome measures over time. The measures included a structured neurological examination, the Kurtzke Functional System scales and Expanded Disability Status Score, and the Incapacity Status Scale from the MS Minimal Record of Disability, the Harvard Ambulation Index, and neuroperformance testing. A test-retest reliability index, principal component analyses and a signal-to-noise ratio metric were used to comparatively evaluate the reliability, validity and sensitivity to disease progression of the various outcome assessments. The goal was to provide a rational basis for selection of behavioral outcome assessments in future MS clinical trials by identifying the primary dimensions of MS measured by the candidate outcome assessments and providing an objective basis for selecting tests that are most sensitive to MS disease and its progression over a two year trial period. We conclude that the components of the major clinical and performance measures show excellent reliability and cross validation. Principal component analyses of all outcome assessments yielded six primary underlying factors for describing disease status in chronic progressive MS that included lower extremity/pyramidal dysfunction, cerebellar/brainstem and upper extremity dysfunction, somatosensory dysfunction, visual dysfunction, mental or intellectual dysfunction and bowel/bladder problems. Signal-to-noise ratios indicated that upper and lower extremity composites of neuroperformance test items provided the most sensitive indicators of MS disease progression in the placebo group over the 2 year trial period.

Clinical outcomes assessment in multiple sclerosis

This article represents initial deliberation of an international task force appointed by the US National Multiple Sclerosis Society to develop recommendations for optimal clinical assessment tools for multiple sclerosis clinical trials. Presented within this article are the key issues identified by the task force during its initial year of deliberation. These include the precise purpose for a clinical assessment tool, the clinical dimensions to be measured in a multidimensional outcome measure, desirable attributes of an optimal clinical outcome measure, the complexities of multidimensional outcome measures, the relative merits of categorical clinical ratings and quantitative functional assessments, and a number of other important design issues that relate to the use of a multidimensional outcome measure. An action plan for analysis of existing data is summarized, as are the plans for more detailed recommendations from the task force.

Natural alpha interferon in multiple sclerosis: results of three preliminary series

In three preliminary, sequential series conducted between 1987-1991, natural human leukocyte interferon-alpha [HuIFN(Le)] was evaluated in 49 interferon-naive multiple sclerosis (MS) patients. In this study, safety data are reported for all 49 patients, and efficacy data for 45 of 49, each patient having received 3-12 months of therapy during the initial study year with observation only in the second year. No major side-effects for HuIFN(Le) were observed at doses of 5-30 million international units (MIU) per week for 3-12 months, although severe fatigue caused some patient drop-outs prior to completion of 3 months of therapy. The relapse rate in patients having received HuIFN(Le), prospectively evaluated in two series (34 patients), was reduced by 80% at 2 years. An unexpected trend towards improved disability provoked a retrospective analysis. In the first year, 36 of 45 (80%) patients improved or stabilized (P = 0.0001); of these 26 of 45 (58%) improved and 10 of 45 (22%) stabilized (P = 0.0023, chi 2 = 9.3). In year 2, 34 of 45 (76%) were improved/stabilized (P = 0.001); of these, 24 of 45 (53%) remained improved and 10 of 45 (22%) remained stable (P = 0.01, chi 2 = 6.6). A trend to greater efficacy at the higher doses for longer periods of therapy, up to 12 months, was observed.

A comparison of two neurologic scoring instruments for multiple sclerosis

We examined the degree of association between two neurologic impairment scales, the Extended Disability Status Scale (EDSS) and the Scripps Neurologic Rating Scale (SNRS), with data from a randomized, double-blind, placebo-controlled clinical trial assessing the safety and efficacy of cladribine as treatment for chronic progressive multiple sclerosis (MS). We found that the EDSS and SNRS were not strongly correlated within individual patients, contrary to expectation; moreover, in 9 of the 48 evaluable patients, the directions of their changes from baseline values were not mutually consistent. The scales were differentially sensitive to clinical changes over time, with the EDSS indicating a more abrupt, and the SNRS a more gradual, change in the clinical course of disease. The validity of different impairment scales, and their sensitivity to detect clinical changes, should be formally assessed in future clinical trials using these scales as outcome measures.

Intramuscular interferon beta-1a for disease progression in relapsing multiple sclerosis. The Multiple Sclerosis Collaborative Research Group (MSCRG)

The accepted standard treatment of relapsing multiple sclerosis consists of medications for disease symptoms, including treatment for acute exacerbations. However, currently there is no therapy that alters the progression of physical disability associated with this disease. The purpose of this study was to determine whether interferon beta-1a could slow the progressive, irreversible, neurological disability of relapsing multiple sclerosis. Three hundred one patients with relapsing multiple sclerosis were randomized into a double-blinded, placebo-controlled, multicenter phase III trial of interferon beta-1a. Interferon beta-1a, 6.0 million units (30 micrograms¿, was administered by intramuscular injection weekly. The primary outcome variable was time to sustained disability progression of at least 1.0 point on the Kurtzke Expanded Disability Status Scale (EDSS). Interferon beta-1a treatment produced a significant delay in time to sustained EDSS progression (p = 0.02). The Kaplan-Meier estimate of the proportion of patients progressing by the end of 104 weeks was 34.9% in the placebo group and 21.9% in the interferon beta-1a-treated group. Patients treated with interferon beta-1a also had significantly fewer exacerbations (p = 0.03) and a significantly lower number and volume of gadolinium-enhanced brain lesions on magnetic resonance images (p-values ranging between 0.02 and 0.05). Over 2 years, the annual exacerbation rate was 0.90 in placebo-treated patients versus 0.61 in interferon beta-1a-treated patients. There were no major adverse events related to treatment. Interferon beta-1a had a significant beneficial impact in relapsing multiple sclerosis patients by reducing the accumulation of permanent physical disability, exacerbation frequency, and disease activity measured by gadolinium-enhanced lesions on brain magnetic resonance images. This treatment may alter the fundamental course of relapsing multiple sclerosis.

Clinical scales for multiple sclerosis

Many neurological rating scales have been suggested to assess the impact of multiple sclerosis on patients, but none has been universally accepted. The Kurtzke Extended Disability Status Scale has been the most widely used despite its imperfections. It combines disability and impairment, has moderate inter-rater reliability, and its overall score is heavily weighted toward ambulation. The Scripps Neurological Rating Scale attempts to quantify impairment as measured by the traditional neurological examination. However, this and other impairment scales lack direct relevance to patients' functional health status. The Ambulation Index and some of the quantitative upper limb dysfunction assessment methods are sensitive and reproducible, but they only measure limited aspects of the wide range of disabilities encountered in multiple sclerosis. Current scales of disability and activities of daily living, such as the Incapacity Status Scale and the Functional Independent Measure, are not sensitive to the type of change which occurs in multiple sclerosis. The relationship between abnormalities on magnetic resonance images of the brain and disability has been difficult to ascertain. Although recently developed imaging acquisition methods may demonstrate abnormalities which are more closely correlated with disability, the demonstration of prevention, stabilization or recovery from disability using clinical scales will remain the final arbiter of success in clinical trials. We suggest guidelines for an improved disability scale.

Meta-analysis of clinical studies of the efficacy of plasma exchange in the treatment of chronic progressive multiple sclerosis

OBJECTIVE

To examine the hypothesis that addition of therapeutic plasma exchange (TPEX) to an immunosuppressive drug regimen increases that regimen's efficacy to halt the progression of chronic progressive multiple sclerosis (CPMS).

METHODS

The literature was searched for prospective controlled clinical trials evaluating the efficacy of TPEX in CPMS. Six studies were eligible for meta-analysis. Their results were combined, using Cochran's and Peto's methods. Three outcome measures were studied: 1) the change in Kurtzke's disability status scale (DSS) scores, 2) the relative odds of neurologic decline by 1 or more DSS grades, and 3) the relative odds of neurologic improvement by 1 or more DSS grades, in the treatment versus the comparison group of patients. Reported results of neurologic evaluations at 6, 12, 24, and 36 months of follow-up were analyzed separately.

RESULTS

TPEX significantly (P < .05) reduced the proportion of patients who experienced neurologic decline (by 1 or more DSS grades) at 12 months of follow-up (relative odds of decline = 0.441, 95% confidence interval = 0.210-0.929).

CONCLUSIONS

There is a need for further clinical research into the possibility of a beneficial effect of TPEX in patients with CPMS likely to experience neurologic decline over the ensuring 12 months. Targeting treatment to a particular subgroup of CPMS patients may be necessary for TPEX to prove effective.

MS COSTAR: a computerized patient record adapted for clinical research purposes

Standardized and computerized neurological data will be a requirement for clinical studies in the future. MS COSTAR is a system that has been designed for multiple sclerosis clinical research. Adoption of standards and a computer method for recording and storing these data should be a high priority for the design and future of multi-center studies on multiple sclerosis.