The Crohn's Disease-Health Index: Development and Evaluation of a Novel Outcome Measure

OBJECTIVE

We sought to develop and validate the Crohn's Disease-Health Index (CD-HI), a disease-specific, patient-reported outcome measure that serially measures Crohn's disease (CD) symptomatic burden in adults with CD.

BACKGROUND

As therapeutic interventions are tested among patients with CD, responsive outcome measures are needed to track disease progression and therapeutic gain during clinical trials.

PATIENTS AND METHODS

We conducted a national cross-sectional study of individuals with CD to identify the most prevalent and impactful symptoms of CD. The most relevant symptoms were included in the CD-HI. We used factor analysis, qualitative patient interviews, test-retest reliability evaluation, and known group validity testing to evaluate and optimize the CD-HI.

RESULTS

The CD-HI contains 12 subscales that comprehensively measure CD burden using the patient's perspective. Fifteen adults with CD beta tested the CD-HI and found the instrument to be clear, easy to use, and relevant to them. Twenty-three adults with CD participated in an assessment of test-retest reliability, which indicated high reliability of individual questions, subscales, and the full instrument (intraclass correlation coefficient = 0.84 for the full instrument). The CD-HI and its subscales demonstrated a high internal consistency (Cronbach α = 0.98 for the full instrument). The CD-HI distinguished between groups of individuals with CD known to differ in disease severity.

CONCLUSIONS

This research supports the use of the CD-HI as a valid, sensitive, reliable, and relevant patient-reported outcome to determine the multifactorial disease burden of those with CD, assess the relevance and merit of future CD therapies, and support drug labeling claims.

Milestones of progression in myotonic dystrophy type 1 and type 2

INTRODUCTION/AIMS

Disease progression in myotonic dystrophy (DM) is marked by milestone events, when functional thresholds are crossed. DM type 2 (DM2) is considered less severe than DM type 1 (DM1), but whether this applies uniformly to all features is unknown. We compared the age-dependent risk for milestone events in DM1 and DM2, and tested for associations with age of onset and sex.

METHODS

We studied a large cohort of adult participants in a national registry of DM1 and DM2. Using annual surveys from participants, we ascertained milestone events for motor involvement (use of cane, walker, ankle brace, wheelchair, or ventilatory device), systemic involvement (diabetes, pacemaker, cancer), loss of employment due to DM, and death.

RESULTS

Mean follow-up of registry participants (DM1 = 929, DM2=222) was 7 years. Disability and motor milestones occurred at earlier ages in DM1 than in DM2. In contrast, the risk of diabetes was higher and tended to occur earlier in DM2 (HR=0.56, p=<0.001). In DM1, the milestone events tended to occur earlier, and life expectancy was reduced, when symptoms began at younger ages. In DM1, men were at greater risk for disability (HR=1.34, p=<0.01), use of ankle braces (HR=1.41, p=0.02), and diabetes (HR=2.2, p=<0.0001), whereas women were at greater risk for using walkers (HR=0.68, p=0.001) or malignancy (0.66, p=<0.01).

DISCUSSION

Milestone events recorded through registries can be used to assess long-term impact of DM in large cohorts. Except for diabetes, the age-related risk of milestone events is greater in DM1 than in DM2.

The Spinal Muscular Atrophy Health Index: A novel outcome for measuring how a patient feels and functions

INTRODUCTION

The Spinal Muscular Atrophy Health Index (SMA-HI) is a multifaceted, disease-specific, patient-reported outcome to measure an SMA patient's perception of their disease burden. In preparation for upcoming therapeutic trials, we examine the validity, reliability, and usability of the SMA-HI in adults, teenagers, and children with SMA.

METHODS

Using data from a cross-sectional study of 359 international adult patients with SMA, we identified the most relevant symptoms to include in the SMA-HI. We utilized factor analysis, patient interviews with adults and minors (age 8-15 years), known-group validity testing, and test-retest reliability assessments to evaluate and refine the SMA-HI.

RESULTS

The SMA-HI measures overall disease burden and 15 areas of SMA health. Fifteen adult patients and five patients, age 8 to 15 years, participated in semistructured qualitative interviews and found the SMA-HI to be comprehensive, easily completed, and to have clear meaning. The final SMA-HI and its subscales demonstrated good internal consistency (Cronbach α = 0.77-0.96), high test-retest reliability (intraclass correlation coefficient = 0.60-0.96), and an ability to differentiate between SMA groups with different disease severities affecting areas such as employment and ambulation (P < .0001 for both).

DISCUSSION

This research provides evidence that the SMA-HI is a valid, relevant, and reliable outcome measure to assess multifaceted patient-reported disease burden in older children, teenagers, and adults with SMA. The SMA-HI provides an opportunity for researchers and clinicians to measure a SMA patient's perception of their health and determine relevant changes in response to therapeutic intervention or disease progression.

Mexiletine in Myotonic Dystrophy Type 1: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

To assess mexiletine's long-term safety and effect on 6-minute walk distance in a well-defined cohort of patients with myotonic dystrophy type 1 (DM1).

METHODS

We performed a randomized, double-blind, placebo-controlled trial of mexiletine (150 mg 3 times daily) to evaluate its efficacy and safety in a homogenous cohort of adult ambulatory patients with DM1. The primary outcome was change in 6-minute walk distance at 6 months. Secondary outcomes included changes in hand grip myotonia, strength, swallowing, forced vital capacity, lean muscle mass, Myotonic Dystrophy Health Index scores, and 24-hour Holter and ECG results at 3 and 6 months.

RESULTS

Forty-two participants were randomized and 40 completed the 6-month follow-up (n = 20 in both groups). No significant effects of mexiletine were observed on 6-minute walk distance, but hand grip myotonia was improved with mexiletine treatment. There were no differences between the mexiletine and placebo groups with respect to the frequency or type of adverse events. Changes in PR, QRS, and QTc intervals were similar in mexiletine- and placebo-treated participants.

CONCLUSIONS

There was no benefit of mexiletine on 6-minute walk distance at 6 months. Although mexiletine had a sustained positive effect on objectively measured hand grip myotonia, this was not seen in measures reflecting participants' perceptions of their myotonia. No effects of mexiletine on cardiac conduction measures were seen over the 6-month follow-up period.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that for ambulatory patients with DM1, mexiletine does not significantly change 6-minute walk distance at 6 months.

Patient-reported study of the impact of pediatric-onset myotonic dystrophy

INTRODUCTION

The prevalence and impact of symptoms affecting individuals with pediatric forms of myotonic dystrophy type-1 (DM1) are not well understood.

METHODS

Patients from the United States, Canada, and Sweden completed a survey that investigated 20 themes associated with pediatric-onset DM1. Participants reported the prevalence and importance of each theme affecting their lives. Surveys from participants were matched with surveys from their caregivers for additional analysis.

RESULTS

The most prevalent symptomatic themes included problems with hands or fingers (79%) and gastrointestinal issues (75%). Problems with urinary/bowel control and gastrointestinal issues were reported to have the greatest impact on patients' lives. Responses from participants and their caregivers had varying levels of agreement among symptomatic themes.

DISCUSSION

Many symptoms have meaningful impact on disease burden. The highest levels of agreement between caregivers and individuals with pediatric forms of myotonic dystrophy were found for physical activity themes.

Patient Reported Impact of Symptoms in Spinal Muscular Atrophy (PRISM-SMA)

OBJECTIVE

To determine the frequency and relative importance of symptoms experienced by adults with spinal muscular atrophy (SMA) and to identify factors that are associated with a higher burden of disease in this population.

METHODS

We conducted a cross-sectional study of 359 adults with SMA using the International SMA Patient Registry. Participants provided input regarding 20 symptomatic themes and 207 symptoms that potentially affect adults with SMA. Participants were asked about the relative importance of each symptom, and analysis was conducted to determine how age, sex, SMA type, education, mobility, and employment status relate to symptom prevalence.

RESULTS

Limitations with mobility or walking (98.6%) and the inability to do activities (98.6%) were the 2 themes with the highest prevalence in the study sample. Limitation with mobility or walking was the theme that was identified as having the greatest effect on the lives of adults with SMA. Employment status was associated with the prevalence of 4 of 20 themes and a reliance on an assistive device was associated with 7 of 20 themes. The prevalence of breathing difficulties, choking or swallowing difficulties, and communication difficulties differed among those with different SMA types.

CONCLUSIONS

There are many symptomatic themes that affect the lives of adults with SMA. These themes vary in prevalence and relative importance in the adult SMA population.

Eight years after an international workshop on myotonic dystrophy patient registries: case study of a global collaboration for a rare disease

BACKGROUND

Myotonic Dystrophy is the most common form of muscular dystrophy in adults, affecting an estimated 10 per 100,000 people. It is a multisystemic disorder affecting multiple generations with increasing severity. There are currently no licenced therapies to reverse, slow down or cure its symptoms. In 2009 TREAT-NMD (a global alliance with the mission of improving trial readiness for neuromuscular diseases) and the Marigold Foundation held a workshop of key opinion leaders to agree a minimal dataset for patient registries in myotonic dystrophy. Eight years after this workshop, we surveyed 22 registries collecting information on myotonic dystrophy patients to assess the proliferation and utility the dataset agreed in 2009. These registries represent over 10,000 myotonic dystrophy patients worldwide (Europe, North America, Asia and Oceania).

RESULTS

The registries use a variety of data collection methods (e.g. online patient surveys or clinician led) and have a variety of budgets (from being run by volunteers to annual budgets over €200,000). All registries collect at least some of the originally agreed data items, and a number of additional items have been suggested in particular items on cognitive impact.

CONCLUSIONS

The community should consider how to maximise this collective resource in future therapeutic programmes.

What Matters Most: A Perspective From Adult Spinal Muscular Atrophy Patients

There are multiple symptoms that affect adults with spinal muscular atrophy (SMA). The extent of these symptoms and their impact on individuals' lives is not fully known. We interviewed 15 adults with genetically confirmed SMA. Participants were asked to identify issues that have significant impact on their lives. Interviews were recorded, transcribed, coded, and analyzed. Participants provided 1045 direct quotes. 177 potential symptoms of importance were identified. Symptoms were grouped by like topics into fourteen symptomatic themes. The symptoms and issues identified by SMA patients alter their physical, mental, and social health and may be amendable to therapeutic intervention.

Myotonic dystrophy patient preferences in patient-reported outcome measures

INTRODUCTION

When preparing for clinical trials in myotonic dystrophy type-1 (DM1), it is important that researchers develop and identify patient-reported outcome measures with good measurement properties.

METHODS

Fifty-two DM1 patients enrolled in 2 clinical studies completed the Myotonic Dystrophy Health Index (MDHI), 36-Item Short Form Health Survey (version 2; SF-36v2), Individualized Neuromuscular Quality of Life questionnaire (INQoL), and a questionnaire comparing the relevance, usability, overall preference, and perceived responsiveness of each measure. The associations between instrument scores and physical function, genetic test results, and employment status were examined.

RESULTS

The MDHI was preferred over the INQoL in 13 of 13 areas and was preferred over the SF-36v2 in 9 of 13 areas. The MDHI was the only score that was associated with participant employment status, CTG repeat length, and the 3 measurements of clinical function.

DISCUSSION

The MDHI correlates well with physical function and is viewed favorably by participants in DM1 clinical studies. Muscle Nerve, 2018.

Myotonic dystrophy health index: Correlations with clinical tests and patient function

INTRODUCTION

The Myotonic Dystrophy Health Index (MDHI) is a disease-specific patient-reported outcome measure. Here, we examine the associations between the MDHI and other measures of disease burden in a cohort of individuals with myotonic dystrophy type-1 (DM1).

METHODS

We conducted a cross-sectional study of 70 patients with DM1. We examined the associations between MDHI total and subscale scores and scores from other clinical tests. Participants completed assessments of strength, myotonia, motor and respiratory function, ambulation, and body composition. Participants also provided blood samples, underwent physician evaluations, and completed other patient-reported outcome measures.

RESULTS

MDHI total and subscale scores were strongly associated with muscle strength, myotonia, motor function, and other clinical measures.

CONCLUSIONS

Patient-reported health status, as measured by the MDHI, is associated with alternative measures of clinical health. These results support the use of the MDHI as a valid tool to measure disease burden in DM1 patients.

Patient-Reported Impact of Symptoms in Myotonic Dystrophy Type 2 (PRISM-2)

OBJECTIVE

To determine the frequency and relative importance of the most life-affecting symptoms in myotonic dystrophy type 2 (DM2) and to identify the factors that have the strongest association with these symptoms.

METHODS

We conducted a cross-sectional study of adult patients with DM2 from a National Registry of DM2 Patients to assess the prevalence and relative importance of 310 symptoms and 21 symptomatic themes. Participant responses were compared by age categories, sex, educational attainment, employment status, and duration of symptoms.

RESULTS

The symptomatic themes with the highest prevalence in DM2 were the inability to do activities (94.4%), limitations with mobility or walking (89.2%), hip, thigh, or knee weakness (89.2%), fatigue (89.2%), and myotonia (82.6%). Participants identified the inability to do activities and fatigue as the symptomatic themes that have the greatest overall effect on their lives. Unemployment, a longer duration of symptoms, and less education were associated with a higher average prevalence of all symptomatic themes (p < 0.01). Unemployment, a longer duration of symptoms, sex, and increased age were associated with a higher average effect of all symptomatic themes among patients with DM2 (p < 0.01).

CONCLUSIONS

The lives of patients with DM2 are affected by a variety of symptoms. These symptoms have different levels of significance and prevalence in this population and vary across DM2 subgroups in different demographic categories.

Myotonic Dystrophy Health Index: initial evaluation of a disease-specific outcome measure

INTRODUCTION

In preparation for clinical trials we examine the validity, reliability, and patient understanding of the Myotonic Dystrophy Health Index (MDHI).

METHODS

Initially we partnered with 278 myotonic dystrophy type-1 (DM1) patients and identified the most relevant questions for the MDHI. Next, we used factor analysis, patient interviews, and test-retest reliability assessments to refine and evaluate the instrument. Lastly, we determined the capability of the MDHI to differentiate between known groups of DM1 participants.

RESULTS

Questions in the final MDHI represent 17 areas of DM1 health. The internal consistency was acceptable in all subscales. The MDHI had a high test-retest reliability (ICC = 0.95) and differentiated between DM1 patient groups with different disease severities.

CONCLUSIONS

Initial evaluation of the MDHI provides evidence that it is valid and reliable as an outcome measure for assessing patient-reported health. These results suggest that important aspects of DM1 health may be measured effectively using the MDHI.

The impact of congenital and childhood myotonic dystrophy on quality of life: a qualitative study of associated symptoms

This study systematically evaluated the symptoms associated with congenital and childhood myotonic dystrophy, and how these symptoms affect health related quality of life. We conducted interviews with patients affected by congenital or childhood myotonic dystrophy and their affected parent to identify which symptoms have the greatest effect on their lives. Each interview was recorded, coded, and analyzed using a qualitative framework technique. In 34 interviews with 13 parents and 21 patients, we identified 189 symptoms, representing 22 themes in physical, emotional, social, and disease-specific quality of life. Communication difficulties, cognitive impairment, and social role limitations were the most frequently identified themes. These interviews identified multiple themes and symptoms, some previously under-recognized, which play a key role in the disease burden associated with congenital and childhood myotonic dystrophy.

High-dosage ascorbic acid treatment in Charcot-Marie-Tooth disease type 1A: results of a randomized, double-masked, controlled trial

IMPORTANCE

No current medications improve neuropathy in subjects with Charcot-Marie-Tooth disease type 1A (CMT1A). Ascorbic acid (AA) treatment improved the neuropathy of a transgenic mouse model of CMT1A and is a potential therapy. A lower dosage (1.5 g/d) did not cause improvement in humans. It is unknown whether a higher dosage would prove more effective.

OBJECTIVE

To determine whether 4-g/d AA improves the neuropathy of subjects with CMT1A.

DESIGN

A futility design to determine whether AA was unable to reduce worsening on the CMT Neuropathy Score (CMTNS) by at least 50% over a 2-year period relative to a natural history control group.

SETTING

Three referral centers with peripheral nerve clinics (Wayne State University, Johns Hopkins University, and University of Rochester).

PARTICIPANTS

One hundred seventy-four subjects with CMT1A were assessed for eligibility; 48 did not meet eligibility criteria and 16 declined to participate. The remaining 110 subjects, aged 13 to 70 years, were randomly assigned in a double-masked fashion with 4:1 allocation to oral AA (87 subjects) or matching placebo (23 subjects). Sixty-nine subjects from the treatment group and 16 from the placebo group completed the study. Two subjects from the treatment group and 1 from the placebo group withdrew because of adverse effects.

INTERVENTIONS

Oral AA (4 g/d) or matching placebo.

MAIN OUTCOMES AND MEASURES

Change from baseline to year 2 in the CMTNS, a validated composite impairment score for CMT.

RESULTS

The mean 2-year change in the CMTNS was -0.21 for the AA group and -0.92 for the placebo group, both better than natural history (+1.33). This was well below 50% reduction of CMTNS worsening from natural history, so futility could not be declared (P > .99).

CONCLUSIONS AND RELEVANCE

Both treated patients and those receiving placebo performed better than natural history. It seems unlikely that our results support undertaking a larger trial of 4-g/d AA treatment in subjects with CMT1A.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00484510.