Prospective trial of natalizumab personalised extended interval dosing by therapeutic drug monitoring in relapsing-remitting multiple sclerosis (NEXT-MS).

BACKGROUND: Extended interval dosing (EID) of natalizumab is a promising strategy to optimise treatment in multiple sclerosis (MS). Personalised EID by therapeutic drug monitoring can enable further extension of treatment intervals. METHODS: The NEXT-MS trial is an investigator-initiated prospective phase IV non-randomised study. Adults with a diagnosis of relapsing-remitting MS who received ≥6 natalizumab infusions were included in three groups: personalised EID with a target drug trough concentration of 10 µg/mL (EID10), an exploratory group of personalised EID with a target of 5 µg/mL (EID5) and standard interval dosing (SID) of 4 weeks. The primary outcome is radiological disease activity (new/newly enlarged T2 lesions) comparing the EID10 group to a historical cohort of SID (HSID). RESULTS: Results of the first phase of the NEXT-MS trial are reported here (n=376) as the study will continue with an amended protocol. In the EID10 group (n=251), incidence rate of radiological activity was 10.0 per 1000 person-years, which was non-inferior to the HSID cohort (24.7 per 1000 person-years (n=87), incidence rate difference 14.7, 90% CI -4.5 to 34.0). Incidence rate of radiological activity was 10.0 per 1000 person-years in the EID5 group (n=65), and 47.0 per 1000 person-years in the SID group (n=60). Serum neurofilament light levels did not increase over time within the EID groups. There were no cases of progressive multifocal leukoencephalopathy. CONCLUSIONS: MS disease activity is adequately controlled with personalised natalizumab EID. Interval extension to a drug trough concentration of 5 µg/mL is likely a safe target to extend natalizumab treatment intervals >6 weeks. TRIAL REGISTRATION NUMBER: NCT04225312.

Relapse recovery in relapsing-remitting multiple sclerosis: An analysis of the CombiRx dataset.

BACKGROUND: Clinical relapses are the defining feature of relapsing forms of multiple sclerosis (MS), but relatively little is known about the time course of relapse recovery. OBJECTIVE: The aim of this study was to investigate the time course of and patient factors associated with the speed and success of relapse recovery in people with relapsing-remitting MS (RRMS). METHODS: Using data from CombiRx, a large RRMS trial (clinicaltrials.gov identifier NCT00211887), we measured the time to recovery from the first on-trial relapse. We used Kaplan-Meier survival analyses and Cox regression models to investigate the association of patient factors with the time to unconfirmed and confirmed relapse recovery. RESULTS: CombiRx included 1008 participants. We investigated 240 relapses. Median time to relapse recovery was 111 days. Most recovery events took place within 1 year of relapse onset: 202 of 240 (84%) individuals recovered during follow-up, 161 of 202 (80%) by 180 days, and 189 of 202 (94%) by 365 days. Relapse severity was the only factor associated with relapse recovery. CONCLUSION: Recovery from relapses takes place up to approximately 1 year after the event. Relapse severity, but no other patient factors, was associated with the speed of relapse recovery. Our findings inform clinical practice and trial design in RRMS.

Threshold definitions for significant change on the timed 25-foot walk and nine-hole peg test in primary progressive multiple sclerosis.

BACKGROUND AND PURPOSE: The timed 25-foot walk (T25FW) and nine-hole peg test (NHPT) exhibit random variability in the short term. A threshold of ≥20% change from baseline has been used to indicate true disability change, but other threshold definitions may be better suited to exclude false and include true change events. The aim of this study was to use patient-level original trial data to investigate the short-term variation in T25FW and NHPT, and to compare its extent with disability change at 12-month follow-up in people with primary progressive multiple sclerosis (PPMS). METHODS: We used original patient-level data from PROMISE, a large PPMS trial. In this trial, three separate T25FW and NHPT measurements were performed 1 week apart during screening. We used these repeated measures to describe the extent of short-term variation. We used binary logistic regression models to investigate the association between screening characteristics and unacceptable short-term variation. RESULTS: The traditional 20% threshold excluded a reasonable number of false change events, while also yielding a large number of change events at follow-up. Increasing index values on the T25FW and NHPT were associated with higher short-term variation. CONCLUSIONS: The traditional ≥20% change threshold for the T25FW and NHPT represents a reasonable compromise between reducing the number of false change events and achieving the largest number of change events in people with PPMS. Our analyses inform the design of clinical trials in PPMS.

Association between age and inflammatory disease activity on magnetic resonance imaging in relapse onset multiple sclerosis during long-term follow-up.

BACKGROUND AND PURPOSE: Inflammatory disease activity in multiple sclerosis (MS) decreases with advancing age. Previous work found a decrease in contrast-enhancing lesions (CELs) with age. Here, we describe the relation of age and magnetic resonance imaging (MRI) measures of inflammatory disease activity during long-term follow-up in a large real-world cohort of people with relapse onset MS. METHODS: We investigated MRI data from the long-term observational Amsterdam MS cohort. We used logistic regression models and negative binomial generalized estimating equations to investigate the associations between age and radiological disease activity after a first clinical event. RESULTS: We included 1063 participants and 10,651 cranial MRIs. Median follow-up time was 6.1 years (interquartile range = 2.4-10.9 years). Older participants had a significantly lower risk of CELs on baseline MRI (40-50 years vs. <40 years: odds ratio [OR] = 0.640, 95% confidence interval [CI] = 0.45-0.90; >50 years vs. <40 years: OR = 0.601, 95% CI = 0.33-1.08) and a lower risk of new T2 lesions or CELs during follow-up (40-50 years vs. <40 years: OR = 0.563, 95% CI = 0.47-0.67; >50 years vs. <40 years: OR = 0.486, 95% CI = 0.35-0.68). CONCLUSIONS: Greater age is associated with a lower risk of inflammatory MRI activity at baseline and during long-term follow-up. In patients aged >50 years, a less aggressive treatment strategy might be appropriate compared to younger patients.

Association of age and inflammatory disease activity in the pivotal natalizumab clinical trials in relapsing-remitting multiple sclerosis.

BACKGROUND: Focal inflammatory disease activity in relapsing-remitting multiple sclerosis (RRMS) diminishes with increasing age. Here we use patient-level data from randomised controlled trials (RCTs) of natalizumab treatment in RRMS to investigate the association of age and inflammatory disease activity. METHODS: We used patient-level data from the AFFIRM (natalizumab vs placebo in relapsing-remitting MS, NCT00027300) and SENTINEL (natalizumab plus interferon beta vs interferon beta in relapsing remitting MS, NCT00030966) RCTs. We determined the proportion of participants developing new T2 lesions, contrast-enhancing lesions (CELs) and relapses over 2 years of follow-up as a function of age, and investigated the association of age with time to first relapse using time-to-event analyses. RESULTS: At baseline, there were no differences between age groups in T2 lesion volume and number of relapses in the year before inclusion. In SENTINEL, older participants had a significantly lower number of CELs. During both trials, the number of new CELs and the proportion of participants developing new CELs were significantly lower in older age groups. The number of new T2 lesions and the proportion of participants with any radiological disease activity during follow-up were also lower in older age groups, especially in the control arms. CONCLUSIONS: Older age is associated with a lower prevalence and degree of focal inflammatory disease activity in treated and untreated RRMS. Our findings inform the design of RCTs, and suggest that patient age should be taken into consideration when deciding on immunomodulatory treatment in RRMS.

Longitudinal Changes in Cognitive Test Scores in Patients With Relapsing-Remitting Multiple Sclerosis: An Analysis of the DECIDE Dataset.

BACKGROUND AND OBJECTIVES: Cognitive impairment is a common and impactful symptom of relapsing-remitting multiple sclerosis (RRMS). Cognitive outcome measures are often used in cross-sectional studies, but their performance as longitudinal outcome measures in clinical trials is not widely researched. In this study, we used data from a large clinical trial to describe change on the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT) over up to 144 weeks of follow-up. METHODS: We used the data set from DECIDE (clinicaltrials.gov identifier NCT01064401), a large randomized controlled RRMS trial to describe change on the SDMT and PASAT over 144 weeks of follow-up. We compared change on these cognitive outcomes with change on the timed 25-foot walk (T25FW), a well-established physical outcome measure. We investigated several definitions for clinically meaningful change: any change, 4-point change, 8-point change, and 20% change for the SDMT, any change, 4-point change, and 20% change for the PASAT, and 20% change for the T25FW. RESULTS: DECIDE included 1,814 trial participants. SDMT and PASAT scores steadily improved throughout follow-up: the SDMT from a mean 48.2 (SD, 16.1) points at baseline to 52.6 (SD 15.2) at 144 weeks and the PASAT from 47.0 (SD 11.3) at baseline to 50.0 (SD 10.8) at 144 weeks. This improvement in scores is most likely due to a practice effect. Throughout the trial, participants were more likely to experience improvement than worsening of their SDMT and PASAT performance, whereas the number of worsening events on the T25FW steadily increased. Changing the definition of clinically meaningful change for the SDMT and PASAT or using a 6-month confirmation changed the overall number of worsening or improvement events but did not affect the overall behavior of these measures. DISCUSSION: Our findings suggest that the SDMT and PASAT scores do not accurately reflect the steady cognitive decline that people with RRMS experience. Both outcomes show postbaseline increases in scores, which complicates the interpretation of these outcome measures in clinical trials. More research into the size of these changes is needed before recommending a general threshold for clinically meaningful longitudinal change.

The nine hole peg test as an outcome measure in progressive MS trials.

BACKGROUND: The nine-hole peg test (NHPT) is the outcome measure with the least change in secondary and primary progressive MS (SPMS and PPMS) trials. The Standard NHPT is defined as the average of four measurements, two in each hand. Little is known about the performance of alternative NHPT scoring methods as longitudinal outcome measures in progressive MS. Non-ambulatory people with progressive MS are now generally excluded from clinical trials, and there is little information on longitudinal NHPT change in this patient group. In this investigation, we used patient-level data from two large randomized controlled trials in progressive MS to explore alternative NHPT scoring methods and NHPT change in non-ambulatory people with progressive MS. METHODS: We used patient-level data from the ASCEND (SPMS, n = 889) and PROMISE (PPMS, n = 943) clinical trials to compare significant change on the Standard NHPT with the alternatives dominant hand (DH), non-dominant hand (NDH), and either hand (EH) NHPT in ambulatory and non-ambulatory trial participants. RESULTS: The Standard NHPT changed slowly and showed few worsening events, as did the DH and NDH alternatives. Using the EH NHPT resulted in a substantial increase of worsening events. Non-ambulatory trial participants with PPMS experienced more NHPT worsening than ambulatory participants, especially when using the EH NHPT. CONCLUSION: Using the EH NHPT yielded substantially more worsening events in people with progressive MS. Clinical trials in non-ambulatory people may be possible with the NHPT as the primary outcome measure. More research into the precision of these measures in this patient group is necessary.

The MSIS-29 and SF-36 as outcomes in secondary progressive MS trials.

BACKGROUND: Patient-reported outcome measures (PROMs) are often used in clinical research, but little is known about their performance as longitudinal outcomes. METHODS: We used data from ASCEND, a large SPMS trial (n = 889), to investigate changes on the Short Form Health Survey 36 (SF-36 v2) and the Multiple Sclerosis Impact Scale (MSIS-29) over 2 years of follow-up. RESULTS: PROM scores changed little over the 2 years of follow-up. In contrast to physical disability measures, there was no consistent trend in PROM change: significant worsening occurred about as often as improvement. Using a 6-month confirmation reduced the number of both worsening and improvement events without altering their relative balance. There was no clear difference in worsening events in groups based on population characteristics, nor was there a noticeable effect using different thresholds for clinically significant change. CONCLUSION: We found little consistent change in MSIS-29 and SF-36 over 2 years of follow-up in people with SPMS. Our findings show a disconnect between disability worsening and PROM change in this population. Our findings raise caution about the use of these PROMs as primary outcome measures in SPMS trials and call for a critical reappraisal of the longitudinal use of these measures in SPMS trials.

The timed 25-foot walk is a more sensitive outcome measure than the EDSS for PPMS trials: an analysis of the PROMISE clinical trial dataset.

BACKGROUND: Clinical trials in primary progressive MS (PPMS) generally use the Expanded Disability Status Scale (EDSS) as their primary outcome measure, although different clinical outcomes may be more useful. Disability worsening in PPMS trials may be influenced by baseline factors, such as age, sex, and contrast-enhancing lesions. METHODS: We used the dataset of PROMISE, a large randomized controlled trial of glatiramer acetate (GA) versus placebo, to compare the clinical outcomes EDSS, timed 25-foot walk (T25FW), and nine-hole peg test (NHPT). We used Cox regression analyses to investigate the association of the baseline factors age, sex, treatment arm, contrast-enhancing lesions (CELs), and EDSS on the time to 3-month confirmed disability worsening (3MCDW) on the EDSS and the T25FW. RESULTS: PROMISE included 943 participants. Worsening on the T25FW or EDSS or occurred much more frequently than on the NHPT. Having CELs at baseline was associated with a shorter time to 3MCDW on both the EDSS and T25FW. An additional resampling experiment using the PROMISE dataset showed that increasing representation of participants with CELs at baseline increases the likelihood of having a positive trial result in favor of GA treatment. CONCLUSION: Our investigation suggests that the T25FW may be a more useful primary outcome measure than the EDSS in PPMS trials, and that its use may shorten clinical trials. Our findings on the impact of CELs at baseline on disability outcomes inform the critical appraisal of clinical trials in PPMS.

Impact of clinical outcomes and imaging measures on health-related quality of life in secondary progressive MS.

BACKGROUND: Health-related quality of life (HRQOL) outcomes are often included as secondary outcomes in clinical trials in secondary progressive MS (SPMS), but little is known about the longitudinal association of HRQOL and clinical and imaging outcome measures in SPMS. OBJECTIVE: To assess the association of change in clinical and imaging outcomes with HRQOL in people with SPMS. METHODS: We used data from ASCEND, a large randomized controlled trial (n = 889), to investigate the association of significant worsening on the Expanded Disability Status Scale (EDSS), Timed 25 Foot Walk (T25FW), Nine Hole Peg Test (NHPT), Symbol Digit Modalities Test (SDMT), and change in lesional and volumetric imaging outcomes with significant worsening on the 36-Item Short Form Health Survey (SF-36) and the Multiple Sclerosis Impact Scale (MSIS-29) during 2 years of follow-up using logistic regression models. RESULTS: HRQOL measures were most associated with EDSS and T25FW, less so with NHPT and SDMT, and not associated with lesional and volumetric imaging outcomes. DISCUSSION: Worsening of the EDSS and T25FW was associated with two commonly used HRQOL measures. These outcomes therefore appear to be more patient relevant than either the NHPT or SDMT in the context of a 2-year clinical trial.

MRI brain volume loss, lesion burden, and clinical outcome in secondary progressive multiple sclerosis.

BACKGROUND: Magnetic resonance imaging (MRI) of brain volume measures are widely used outcomes in secondary progressive multiple sclerosis (SPMS), but it is unclear whether they are associated with physical and cognitive disability. OBJECTIVE: To investigate the association between MRI outcomes and physical and cognitive disability worsening in people with SPMS. METHODS: We used data from ASCEND, a large randomized controlled trial (n = 889). We investigated the association of change in whole brain and gray matter volume, contrast enhancing lesions, and T2 lesions with significant worsening on the Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), Nine-Hole Peg Test (NHPT), and Symbol Digit Modalities Test (SDMT) with logistic regression models. RESULTS: We found no association between MRI measures and EDSS or SDMT worsening. T25FW worsening at 48 and 96 weeks, and NHPT worsening at 96 weeks were associated with cumulative new or newly enlarging T2 lesions at 96 weeks. NHPT worsening at 48 and 96 weeks was associated with normalized brain volume loss at 48 weeks, but not with other MRI outcomes. CONCLUSION: The association of standard MRI outcomes and disability was noticeably weak and inconsistent over 2 years of follow-up. These MRI outcomes may not be useful surrogates of disability measures in SPMS.

Smoking, obesity, and disability worsening in PPMS: an analysis of the INFORMS original trial dataset.

BACKGROUND: Smoking and obesity are recognized modifiable risk factors associated with a higher MS incidence, but their impact on physical and cognitive disability worsening is less clear. OBJECTIVE: To investigate the impact of smoking and obesity on disability worsening in primary progressive MS (PPMS). METHODS: We used data from INFORMS (clinicaltrials.gov identifier: NCT00731692), a large randomized-controlled trial in PPMS to compare significant worsening on the EDSS, T25FW, NHPT, and PASAT between smokers and non-smokers, and between BMI groups, at 12, 24, and 33 months of follow-up. We investigated the association of smoking and BMI at screening and the risk of disability worsening with logistic regression models. RESULTS: Smokers had significantly higher EDSS scores throughout the trial. EDSS was not significantly different between BMI categories. No other outcome measure was significantly different between smokers and non-smokers and between BMI categories throughout the trial. Neither smoking status nor BMI were associated with significant worsening on any outcome measure at any time point during follow-up. CONCLUSION: Despite the known effects on MS incidence, smoking and BMI were not associated with the risk of physical and cognitive disability worsening over 3 years in this well-characterized PPMS trial cohort.

Early first-line treatment response and subsequent disability worsening in relapsing-remitting multiple sclerosis.

BACKGROUND AND PURPOSE: Treatment success in relapsing-remitting multiple sclerosis (RRMS) is generally determined using relapse frequency and magnetic resonance imaging (MRI) activity in the first 6 or 12 months on treatment. The association of these definitions of short-term treatment success with disability worsening and disease activity in the longer term is unclear. In this study, we investigated risk factors associated with early first-line treatment failure in RRMS, and the association of early treatment failure with subsequent disability worsening or "no evidence of disease activity" (NEDA-3) status. METHODS: We used data from CombiRx (clinicaltrials.gov identifier NCT00211887) to investigate risk factors associated with early treatment failure, and the association of early treatment failure at 6 and 12 months with subsequent disability worsening or NEDA-3 at 36 months. RESULTS: CombiRx included 1008 treatment-naïve participants with RRMS, who were randomly assigned to treatment with glatiramer acetate, interferon beta, or the combination of both. Early treatment failure at 6 or 12 months by several definitions was associated with NEDA-3 failure at 36 months, but not with subsequent disability worsening at 36 months. Expanded Disability Status Scale (EDSS) was the only baseline characteristic associated with the risk of disability worsening at 36 months. Approximately 70% of NEDA-3 failures occurred due to MRI activity, and <10% occurred due to EDSS worsening. CONCLUSIONS: Our investigation shows that current definitions of early treatment failure in RRMS are unrelated to patient-relevant disability worsening at 36 months of follow-up. Further research into useful definitions of treatment success and failure in RRMS is needed.

Association of Age With Contrast-Enhancing Lesions Across the Multiple Sclerosis Disease Spectrum.

BACKGROUND AND OBJECTIVES: To investigate the association of age and the presence of contrast-enhancing lesions (CELs) on cranial MRI scans in different disease courses of multiple sclerosis (MS), we describe the frequency of CELs as a function of age in 4 large randomized controlled trial (RCT) datasets. METHODS: Using original trial data from CombiRx (Combination Therapy in Patients With Relapsing-Remitting Multiple Sclerosis; clinicaltrials.gov identifier NCT00211887), a trial in relapsing-remitting MS; ASCEND (A Clinical Study of the Efficacy of Natalizumab on Reducing Disability Progression in Participants With Secondary Progressive Multiple Sclerosis; clinicaltrials.gov identifier NCT01416181), a trial in secondary progressive MS; and the 2 primary progressive MS trials PROMISE and INFORMS; clinicaltrials.gov identifier NCT00731692), we describe the occurrence of CELs per age group at baseline for the entire trial cohort and at 1 year follow-up in the treatment arms. RESULTS: CombiRx included 1,008, ASCEND 889, PROMISE 943, and INFORMS 970 participants. At baseline, CEL frequency differed between datasets according to disease course: 39.6% of CombiRx, 23.9% of ASCEND, 14.0% of PROMISE, and 12.3% of INFORMS participants had CELs. This distribution by disease course was largely preserved within each age group. In all datasets, there was an almost linear decrease of the percentage of participants with CELs with advancing age. After 1 year of experimental treatment, CEL occurrence was reduced in all trial datasets, and almost absent in ASCEND. The decrease of CEL occurrence with advancing age was preserved in CombiRx, PROMISE, and INFORMS after 1 year of treatment. We investigated the association of the baseline factors age, disease duration, sex, and EDSS with having CELs at baseline with multivariable binary logistic regression models. Age was the only characteristic associated with the risk of CELs at baseline in all datasets, with higher age associated with a lower risk of CELs (odds ratios for having CELs at baseline per year increase in age: CombiRx: 0.96, 95% confidence interval [CI] 0.95-0.98; ASCEND: 0.94, 95% CI 0.92-0.97; PROMISE: 0.94, 95% CI 0.91-0.96; INFORMS: 0.97, 95% CI 0.94-0.99). DISCUSSION: Our analysis of 4 large, well-characterized RCT datasets shows that the association of age and CEL occurrence is a general phenomenon across the spectrum of MS disease courses. Our findings should be replicated in real-world MS datasets.

Comparison of the EDSS, Timed 25-Foot Walk, and the 9-Hole Peg Test as Clinical Trial Outcomes in Relapsing-Remitting Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Clinical trials in relapsing-remitting multiple sclerosis (RRMS) usually use the Expanded Disability Status Scale (EDSS) as their primary disability outcome measure, while the more recently developed outcomes timed 25-ft walk (T25FW) and 9-hole peg test (NHPT) may be more useful and patient relevant. The objective of this work was to compare the EDSS to the T25FW and NHPT in a large RRMS randomized controlled trial (RCT) dataset. METHODS: We used the dataset from Combination Therapy in Patients With Relapsing-Remitting Multiple Sclerosis (CombiRx) (clinicaltrials.gov identifier NCT00211887), a large phase 3 RCT, to compare the EDSS to the alternative outcomes T25FW and NHPT. We investigated disability worsening vs similarly defined improvement, unconfirmed vs confirmed and sustained disability change, and the presentation methods cumulative Kaplan-Meier survival curves vs cross-sectional disability worsening. RESULTS: CombiRx included 1,008 participants. A comparison of confirmed and sustained worsening events showed that, throughout the trial, there were substantially fewer sustained than confirmed events, with a positive predictive value of confirmed for sustained worsening at 24 months of 0.73 for the EDSS, 0.73 for the T25FW, and 0.8 for the NHPT. More concerning were the findings that worsening on the EDSS occurred as frequently as similarly defined improvement throughout the 3 years of follow-up and that improvement rates increased in parallel with worsening rates. The T25FW showed low improvement rates of <10% throughout the trial. We also found that Kaplan-Meier survival analysis, the standard presentation and analysis method in modern RRMS trials, yields exaggerated estimates of disability worsening. With the Kaplan-Meier method, the proportion of patients with worsening events steadily increases until it reaches several-fold the number of events seen with more conservative analysis methods. For 3-month confirmed disability worsening up to 36 months, the Kaplan-Meier method yields 2.6-fold higher estimates for the EDSS, 2.9-fold higher estimates for the T25FW, and 5.1-fold higher estimates for the NHPT compared to a more conservative presentation of the same data. DISCUSSION: Our analyses raise concerns about using the EDSS as the standard disability outcome in RRMS trials and suggest that the T25FW may be a more useful measure. These findings are relevant for the design and critical appraisal of RCTs.

Is the Symbol Digit Modalities Test a useful outcome in secondary progressive multiple sclerosis?

BACKGROUND: It is unclear which cognitive outcome measure is the most useful for clinical trials in multiple sclerosis. To investigate the usefulness of the Symbol Digit Modalities Test (SDMT) as a clinical outcome measure in secondary progressive multiple sclerosis (SPMS), we describe the frequency of worsening and improvement events in a large randomized controlled trial (RCT) dataset. METHODS: Using original trial data from the ASCEND trial (n = 889), a recent large RCT in SPMS, we describe worsening and similarly defined improvement with and without 3-month confirmation on the SDMT in the whole trial cohort and unconfirmed worsening and improvement on the Paced Auditory Serial Addition Test (PASAT) in a smaller subset (n = 107). RESULTS: Somewhat unexpectedly, SDMT scores steadily increased throughout the 2 years of follow-up in this trial. There were overall few SDMT worsening events throughout the trial (generally fewer than 10% of participants), but improvement events steadily increased from around 50% of participants with improvement at 12 weeks to more than 70% at 84 weeks and beyond. PASAT scores followed a similar pattern. CONCLUSIONS: In this well-characterized clinical trial cohort, the SDMT does not reflect the steady cognitive decline that patients with SPMS experience. Both SDMT and PASAT scores improve throughout follow-up, possibly due to a practice effect. The SDMT may not be a useful outcome measure of disease progression in 2-year clinical trials in SPMS.

A comparison of clinical outcomes in PPMS in the INFORMS original trial data set.

BACKGROUND: The expanded disability status scale (EDSS) is the standard clinical outcome measure in primary progressive multiple sclerosis (PPMS), even though the timed 25-foot walk (T25FW), nine-hole peg test (NHPT) or combinations of these measures may be more useful. The paced auditory serial addition test (PASAT) is a widely used cognitive measure in MS, but little is known about change in PASAT scores over time in PPMS. OBJECTIVE: The objective of this study is to compare clinical outcome measures in a large PPMS trial data set. METHODS: We determined significant worsening events on the EDSS, T25FW and NHPT, and PASAT scores over the course of this 3-year trial. We compared unconfirmed, confirmed and sustained disability worsening and contrasted disability worsening with similarly defined improvement. We examined the association of baseline characteristics with the risk of disability worsening at 12, 24 and 36 months with logistic regression models. RESULTS: The EDSS and T25FW showed most worsening events, while only few patients worsened on the NHPT. Adding the NHPT to a combined outcome added only few further worsening events. PASAT scores slightly increased over time, possibly due to a practice effect. CONCLUSION: Both the EDSS and T25FW, but not NHPT or PASAT, appear to be useful outcome measures in PPMS.

A Dutch validation study of the Multiple Sclerosis Work Difficulties Questionnaire in relapsing remitting multiple sclerosis.

PURPOSE: The current study aimed to evaluate the psychometric properties of the Dutch version of the Multiple Sclerosis Work Difficulties Questionnaire-23 (MSWDQ-23). METHODS: Two hundred and thirty-nine employed persons with multiple sclerosis (MS) and 59 healthy controls completed the MSWDQ-23. To verify the factor structure, a confirmatory factor analysis was conducted. To assess construct validity, the MSWDQ-23 scores were correlated to measures of physical disability, fatigue, cognitive and neuropsychiatric problems, depression, health-related quality of life, and work-related variables. MSWDQ-23 scores were compared within different age groups, gender, education levels, and job types. Predictive validity was assessed using a logistic regression analysis to predict a deterioration in employment status after one year based on MSWDQ-23 scores. RESULTS: The internal consistency of the MSWDQ-23 was acceptable (α = 0.913, 95% CI = 0.897-0.928) and the results indicated a fair fit. The MSWDQ-23 showed acceptable construct validity, confirming 94% of the hypotheses. The total scale and the psychological/cognitive subscale were able to predict a deterioration in employment status after one year (χ2(1)=18.164, p < 0.001). CONCLUSIONS: The Dutch version of the MSWDQ-23 is a valid and internally consistent instrument to measure self-reported work difficulties in persons with MS.Implications for rehabilitationThe Dutch version of the 23-item Multiple Sclerosis Work Difficulties Questionnaire (MSWDQ-23) is a reliable and valid tool to measure self-reported work difficulties in people with multiple sclerosis (MS).More psychological and cognitive work difficulties are predictive of a deteriorated employment status after one year.The MSWDQ-23 is a helpful tool for researchers and (occupational) health professionals to identify current work difficulties in persons with MS and identify persons at risk for a deterioration in employment one year later.

Reliability of Outcome Measures in Clinical Trials in Secondary Progressive Multiple Sclerosis.

OBJECTIVE: To investigate the reliability of clinical outcomes in secondary progressive multiple sclerosis (SPMS) trials, we compared the frequency of progression and improvement events on different clinical outcome measures in the placebo arms of 2 large randomized controlled trial (RCT) datasets. METHODS: Using original trial data from the placebo arms of IMPACT (International MS Secondary Progressive Avonex Controlled Trial) and ASCEND (A Clinical Study of the Efficacy of Natalizumab on Reducing Disability Progression in Participants With Secondary Progressive Multiple Sclerosis), 2 large RCTs in SPMS, we compared disability progression and similarly defined improvement with and without 3- or 6-month confirmation on the outcome measures Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT), and their combinations. RESULTS: In both datasets, the EDSS showed the highest rates of improvement over time, and the smallest difference between progression and improvement rates, followed by the T25FW and the 9HPT. For the T25FW and 9HPT, improvement rates were fairly stable over time and remained at below or around the 10% level. For the EDSS, improvement rates increased in parallel with disability progression rates. CONCLUSIONS: All investigated outcome measures in SPMS showed some evidence of random variation and measurement error, the T25FW and 9HPT less so than the more established outcome EDSS. Our findings are relevant for the design and critical appraisal of trials in SPMS.