Facioscapulohumeral muscular dystrophy Health Index: Japanese translation and validation study

Abstract

Purpose

The Facioscapulohumeral Muscular Dystrophy Health Index (FSHD-HI) is a patient-reported outcome measure developed for patients with FSHD. This study aimed to translate the FSHD-HI into Japanese (FSHD-HI-J), evaluate cultural adaptation, and examine its psychometric properties.

Materials and methods

We created two forward translations, integrated them into a single Japanese version, and evaluated the back-translated version of the FSHD-HI. After finalizing the translation and cultural adaptation, we conducted a survey of 66 patients with FSHD to examine the reliability and validity of the FSHD-HI-J. For psychometric evaluations, we used Cronbach’s alpha to assess internal consistency, the intraclass correlation coefficient (ICC) for test-retest reliability, and assessed validity based on the associations between FSHD-HI-J, clinical variables, and quality of life measures.

Results

The FSHD-HI-J was found to be clinically relevant, indicating high internal consistency and test-retest reliability (ICC = 0.92 [95% confidence interval: 0.86-0.95] for the total score), as well as significant associations with clinical variables (D4Z4 repeats and functional impairment) and other quality of life measures (|rho| = 0.25-0.73).

Conclusions

The FSHD-HI-J is a valid and reliable patient-reported outcome measure for Japanese patients with FSHD. This validated, disease-specific patient-reported outcome is essential for future clinical practice and clinical trials.

IMPLICATIONS FOR REHABILITATION

• Facioscapulohumeral muscular dystrophy (FSHD) affects not only a patient’s physical abilities but also their social activities, participation, and overall quality of life.

• The FSHD-Health Index (FSHD-HI) is an instrument developed as a disease-specific patient-reported outcome measure to evaluate the burden experienced by patients.

• The Japanese version of the FSHD-HI has been established as a reliable and validated measure for Japanese-speaking patients with FSHD.

• The Japanese version of the FSHD-HI can serve as a useful instrument for evaluating the effectiveness of interventions in future trials.

Keywords:

• Facioscapulohumeral muscular dystrophy
• patient-reported outcomes
• disease burden
• quality of life
• neuromuscular disorder

Ethics approval

All procedures involving human participants performed in this study were in accordance with ethical standards and the 1964 Helsinki Declaration and its later amendments. Consent was obtained from all study participants in the questionnaire form. This study was approved by the Institutional Review Board of Osaka Toneyama Medical Center (approval no. TNH-2019041 and TNH-R-2021035).

Author contributions

Haruo Fujino: Conceptualization; Data curation; Formal Analysis; Investigation; Methodology; Validation; Visualization; Writing – Original Draft; Writing – Review & Editing, Masanori P Takahashi: Conceptualization; Investigation; Methodology; Resources; Supervision; Writing – review & editing, Harumasa Nakamura: Conceptualization; Investigation; Methodology; Resources; Writing – review & editing, Chad R. Heatwole: Conceptualization; Data curation; Investigation; Resources; Writing – review & editing, Hiroto Takada: Investigation; Resources; Writing – review & editing, Satoshi Kuru: Investigation; Resources; Writing – review & editing, Katsuhisa Ogata: Investigation; Resources; Writing – review & editing, Kiyoka Enomoto: Formal Analysis; Writing – review & editing, Yuto Hayashi: Investigation; Writing – review & editing, Osamu Imura: Investigation; Writing – review & editing, Tsuyoshi Matsumura: Conceptualization; Data curation; Funding acquisition; Investigation; Methodology; Project administration; Resources; Supervision; Writing – review & editing

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets generated and/or analyzed during the current study are not publicly available because of privacy constraints related to ethical approval, but are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported in part by research grants from the Ministry of Health, Labour and Welfare of Japan (21FC1006). The funders had no role in the study design, data collection and analysis, decision to publish, or manuscript preparation.