French translation and cross-cultural adaptation of The Myotonic Dystrophy Health Index

Quality of instruments assessing activity and participation of people with muscular dystrophy: A systematic review of participant-reported outcome measures

AIM

To identify the standardized assessment scales for people with muscular dystrophy and investigate the quality/level of evidence of their measurement properties.

METHOD

A systematic review of patient-reported outcome measures was conducted on the MEDLINE, Embase, AMED, DiTA, and PsycINFO databases in August 2020. We included psychometric studies that investigated the validity, reliability, and responsiveness of instruments assessing activity and participation for muscular dystrophy of any type (Duchenne, Becker, limb-girdle, facioscapulohumeral, congenital, and myotonic) or age. Two independent reviewers selected the studies, extracted data, and evaluated the instruments' quality and level of evidence following the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The study followed the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) 2020 guidelines.

RESULTS

The searches identified 6675 references; a total of 46 studies with 28 condition-specific or general instruments were included. The measurement properties of most instruments had sufficient (68.8%) or indeterminate (25.7%) results according to COSMIN. The quality of evidence of the measurement properties was moderate (23.8%) or low (22.6%) according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

INTERPRETATION

There is a lack of high-quality instruments whose psychometric properties are adequately measured. The highest quality instrument is the Muscular Dystrophy Functional Rating Scale. The Motor Function Measure (general instrument), Duchenne Muscular Dystrophy Upper-limb Patient-reported Outcome Measure, North Star Ambulatory Assessment, and Myotonic Dystrophy Type 1 Activity and Participation Scale for Clinical Use (specific) are also recommended.

WHAT THIS PAPER ADDS

There are 28 available instruments for activity and participation of people with muscular dystrophy. The evidence quality is moderate or low because of imprecision and indirectness. The Muscular Dystrophy Functional Rating Scale is the highest quality instrument. The Motor Function Measure is the second most recommended instrument. The Duchenne Muscular Dystrophy Upper-limb Patient-reported Outcome Measure, North Star Ambulatory Assessment, and Myotonic Dystrophy Type 1 Activity and Participation Scale for Clinical Use are also recommended.

Quality of life and subjective symptom impact in Japanese patients with myotonic dystrophy type 1

BACKGROUND

Although functional impairment in patients with myotonic dystrophy is an important determinant of the quality of life (QoL), patients' subjective evaluation of their symptoms may also affect their QoL. The aim of this study was to investigate the association between subjective symptom impact and the QoL of patients with myotonic dystrophy, after controlling for functional impairment.

METHODS

Eligible patients with myotonic dystrophy type 1 (DM1) were recruited from four hospitals in Japan. The subjective symptom impact of four symptoms (muscle weakness, fatigue, pain, and myotonia) and overall QoL were evaluated using the Individualized Neuromuscular Quality of Life (INQoL) questionnaire. Functional impairment was assessed using the modified Rankin Scale.

RESULTS

Seventy-seven patients with DM1 were included in this study. Overall QoL was significantly associated with subjective symptom impact of muscular weakness, fatigue, pain, myotonia, swallowing difficulty, and droopy eyelids. In the regression models, disease duration (beta = 0.11) and moderate to severe functional impairment (beta = 0.33) explained a significant part of the overall QoL. Furthermore, muscular weakness, fatigue, and myotonia significantly explained additional variance of the overall QoL (beta = 0.17-0.43).

CONCLUSIONS

Subjective symptom impact and functional impairment are independent features influencing the QoL of Japanese patients with DM1.

The myotonic dystrophy health index: Japanese adaption and validity testing

INTRODUCTION

The Myotonic Dystrophy Health Index (MDHI) is a disease-specific, patient-reported outcome measure. The objective of this study was to translate, evaluate, and validate a Japanese version of the MDHI (MDHI-J).

METHODS

We utilized forward and backward translations and qualitative interviews with 11 myotonic dystrophy type 1 (DM1) participants. We subsequently tested the internal consistency, test-retest reliability, concurrent validity against muscle strength, and 3 quality-of-life measures, and the known-groups validity of the MDHI-J with 60 adult patients.

RESULTS

The MDHI-J was found to be culturally appropriate, comprehensive, and clinically relevant. The MDHI-J and its subscales had high internal consistency (mean Cronbach's α = 0.91), test-retest reliability (intraclass coefficient 0.678-0.915), and concurrent validity (Spearman's ρ - 0.869 to 0.904). MDHI-J scores were strongly associated with employment, duration of symptoms, and modified Rankin Scale.

DISCUSSION

The MDHI-J is suitable and valid to measure patient-reported disease burden in adult Japanese patients with DM1. Muscle Nerve 59:577-577, 2019.

The Charcot-Marie-Tooth Health Index: Evaluation of a Patient-Reported Outcome

OBJECTIVE

The development of a disease-specific patient-reported outcome for Charcot-Marie-Tooth disease is an important step in the preparation for therapeutic trials. This study describes the development of the Charcot-Marie-Tooth Health Index (CMTHI).

METHODS

Inherited Neuropathy Consortium Contact Registry participants were queried on the symptoms that most impacted their lives. The CMTHI was developed based on these responses. Factor analysis, assessment of test-retest reliability, known group validity, and patient interviews were utilized to refine the instrument.

RESULTS

The final CMTHI contains 18 themes that capture Charcot-Marie-Tooth disease (CMT) burden. The CMTHI has a high internal consistency and test-retest reliability. The CMTHI was able to discriminate between patient groups expected to have different disease burden. The CMTHI was able to discriminate levels of disability as measured by the CMT examination score and the mobility-Disability Severity Index.

INTERPRETATION

The CMTHI represents a valid and reliable outcome to assess patient-reported disease burden in CMT. Ann Neurol 2018;84:225-233.