Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study

Abstract Background Barth syndrome (BTHS) is a rare, X-linked disorder that stems from mutations in the TAFAZZIN (TAZ) gene with varying disease severity among patients. The Barth Syndrome Symptom Assessment (BTHS-SA) is a patient-reported outcome questionnaire developed to assess BTHS symptom sever...

Full description

Saved in:
Bibliographic Details
Main Authors: Chad Gwaltney, Alan Shields, Emily Love, Sarah Ollis, Jonathan Stokes, Iyar Mazar, Ethan Arenson, Anthony Aiudi, R. J. Wirth, Carrie Houts
Format: Article
Language:English
Published: BMC 2025-04-01
Series:Orphanet Journal of Rare Diseases
Subjects:
Online Access:https://doi.org/10.1186/s13023-025-03693-5
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850143392684572672
author Chad Gwaltney
Alan Shields
Emily Love
Sarah Ollis
Jonathan Stokes
Iyar Mazar
Ethan Arenson
Anthony Aiudi
R. J. Wirth
Carrie Houts
author_facet Chad Gwaltney
Alan Shields
Emily Love
Sarah Ollis
Jonathan Stokes
Iyar Mazar
Ethan Arenson
Anthony Aiudi
R. J. Wirth
Carrie Houts
author_sort Chad Gwaltney
collection DOAJ
description Abstract Background Barth syndrome (BTHS) is a rare, X-linked disorder that stems from mutations in the TAFAZZIN (TAZ) gene with varying disease severity among patients. The Barth Syndrome Symptom Assessment (BTHS-SA) is a patient-reported outcome questionnaire developed to assess BTHS symptom severity. The current study reflects the first exploration of the assessment’s psychometric performance. Methods The BTHS-SA was administered in TAZPOWER, a phase 2, randomized, double-blind, placebo-controlled crossover study to evaluate daily subcutaneous injections of elamipretide in subjects with genetically confirmed BTHS. Descriptive and correlational analyses were used to assess the score distributions, reliability, and construct-related validity of BTHS-SA items and domains including a two-item (2 FS), three-item (3 FS), and four-item (4 FS) fatigue score, and a five-item myopathy score (5MS). Results Among the N = 12 white males (M age = 19.5, SD = 7.7) participating in the TAZPOWER trial, overall symptoms were rated as mild (n = 5, 41.7%), moderate (n = 5, 41.7%), severe (n = 1, 8.3%), or very severe (n = 1, 8.3%). Descriptive statistics for the BTHS-SA scores indicate variability of symptom severity both within symptom cluster and across patients. Promising results were found for both internal consistency (α = 0.67, 0.72, and 0.66 for the 3 FS, 4 FS, and 5MS, respectively) and test–retest reliability (ICC values ranging from 0.79 to 0.94 across two test–retest intervals). Correlational analyses showing moderate to strong relationships to other patient reports of fatigue (e.g., r = 0.59, 0.76, 0.68, and 0.61 between the PROMIS Fatigue SF and the 2 FS, 3 FS, 4 FS, and 5MS, respectively) and symptom severity (e.g., r = 0.60, 0.62, 0.56, 0.53 between a patient global rating and the 2 FS, 3 FS, 4 FS, and 5MS, respectively) support the measure’s convergent validity. A similar pattern of relationships was observed when correlating changes in BTHS-SA scores to reference measures, including moderate to strong relationships between the BTHS-SA and direct patient reports of change (r = 0.81, 0.79, 0.82, and 0.80 between a global impression of change score and the 2 FS, 3 FS, 4 FS, and 5MS, respectively). Conclusion Though the small sample size limits strong conclusions, this analysis suggests the BTHS-SA can produce reliable scores upon which valid inferences may be drawn. The BTHS-SA may be a useful tool to evaluate treatment benefits in this underserved population. Trial registration ClinicalTrials.gov identifier, NCT03098797. Registered 05 May 2017, https://www.clinicaltrials.gov/study/NCT03098797 .
format Article
id doaj-art-6c5ddcc76247455cb11a1fccbc284596
institution OA Journals
issn 1750-1172
language English
publishDate 2025-04-01
publisher BMC
record_format Article
series Orphanet Journal of Rare Diseases
spelling doaj-art-6c5ddcc76247455cb11a1fccbc2845962025-08-20T02:28:42ZengBMCOrphanet Journal of Rare Diseases1750-11722025-04-012011910.1186/s13023-025-03693-5Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical StudyChad Gwaltney0Alan Shields1Emily Love2Sarah Ollis3Jonathan Stokes4Iyar Mazar5Ethan Arenson6Anthony Aiudi7R. J. Wirth8Carrie Houts9Gwaltney Consulting GroupAdelphi ValuesAdelphi ValuesAdelphi ValuesAdelphi ValuesAdelphi ValuesAdelphi ValuesStealth BioTherapeuticsVector Psychometric GroupVector Psychometric GroupAbstract Background Barth syndrome (BTHS) is a rare, X-linked disorder that stems from mutations in the TAFAZZIN (TAZ) gene with varying disease severity among patients. The Barth Syndrome Symptom Assessment (BTHS-SA) is a patient-reported outcome questionnaire developed to assess BTHS symptom severity. The current study reflects the first exploration of the assessment’s psychometric performance. Methods The BTHS-SA was administered in TAZPOWER, a phase 2, randomized, double-blind, placebo-controlled crossover study to evaluate daily subcutaneous injections of elamipretide in subjects with genetically confirmed BTHS. Descriptive and correlational analyses were used to assess the score distributions, reliability, and construct-related validity of BTHS-SA items and domains including a two-item (2 FS), three-item (3 FS), and four-item (4 FS) fatigue score, and a five-item myopathy score (5MS). Results Among the N = 12 white males (M age = 19.5, SD = 7.7) participating in the TAZPOWER trial, overall symptoms were rated as mild (n = 5, 41.7%), moderate (n = 5, 41.7%), severe (n = 1, 8.3%), or very severe (n = 1, 8.3%). Descriptive statistics for the BTHS-SA scores indicate variability of symptom severity both within symptom cluster and across patients. Promising results were found for both internal consistency (α = 0.67, 0.72, and 0.66 for the 3 FS, 4 FS, and 5MS, respectively) and test–retest reliability (ICC values ranging from 0.79 to 0.94 across two test–retest intervals). Correlational analyses showing moderate to strong relationships to other patient reports of fatigue (e.g., r = 0.59, 0.76, 0.68, and 0.61 between the PROMIS Fatigue SF and the 2 FS, 3 FS, 4 FS, and 5MS, respectively) and symptom severity (e.g., r = 0.60, 0.62, 0.56, 0.53 between a patient global rating and the 2 FS, 3 FS, 4 FS, and 5MS, respectively) support the measure’s convergent validity. A similar pattern of relationships was observed when correlating changes in BTHS-SA scores to reference measures, including moderate to strong relationships between the BTHS-SA and direct patient reports of change (r = 0.81, 0.79, 0.82, and 0.80 between a global impression of change score and the 2 FS, 3 FS, 4 FS, and 5MS, respectively). Conclusion Though the small sample size limits strong conclusions, this analysis suggests the BTHS-SA can produce reliable scores upon which valid inferences may be drawn. The BTHS-SA may be a useful tool to evaluate treatment benefits in this underserved population. Trial registration ClinicalTrials.gov identifier, NCT03098797. Registered 05 May 2017, https://www.clinicaltrials.gov/study/NCT03098797 .https://doi.org/10.1186/s13023-025-03693-5Barth syndromeBarth syndrome symptom assessmentBTHS-SAInstrument developmentPatient-reported outcomePRO
spellingShingle Chad Gwaltney
Alan Shields
Emily Love
Sarah Ollis
Jonathan Stokes
Iyar Mazar
Ethan Arenson
Anthony Aiudi
R. J. Wirth
Carrie Houts
Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study
Orphanet Journal of Rare Diseases
Barth syndrome
Barth syndrome symptom assessment
BTHS-SA
Instrument development
Patient-reported outcome
PRO
title Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study
title_full Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study
title_fullStr Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study
title_full_unstemmed Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study
title_short Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study
title_sort initial psychometric evaluation of the barth syndrome symptom assessment bths sa for adolescents and adults in a phase 2 clinical study
topic Barth syndrome
Barth syndrome symptom assessment
BTHS-SA
Instrument development
Patient-reported outcome
PRO
url https://doi.org/10.1186/s13023-025-03693-5
work_keys_str_mv AT chadgwaltney initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT alanshields initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT emilylove initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT sarahollis initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT jonathanstokes initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT iyarmazar initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT ethanarenson initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT anthonyaiudi initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT rjwirth initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy
AT carriehouts initialpsychometricevaluationofthebarthsyndromesymptomassessmentbthssaforadolescentsandadultsinaphase2clinicalstudy