Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Mar 4:16:1509174.
doi: 10.3389/fneur.2025.1509174. eCollection 2025.

A patient-centered qualitative evaluation of meaningful change on the NSAA and PUL in Duchenne Muscular Dystrophy

Aviva Gillman  1 , Teofil Ciobanu  2 , Louise Barrett  1 , Evan W Davies  2 , Alexander P Murphy  3 , Alex Johnson  4 , Jessica Mills  1 , Phoebe Heinrich  1 , Krystian Przydzial  1 , Bethany Ewens  1 , Gerrit Vandenberg  1 , Stefan Cano  1 , Anna Mayhew  5
Affiliations

A patient-centered qualitative evaluation of meaningful change on the NSAA and PUL in Duchenne Muscular Dystrophy

Aviva Gillman et al. Front Neurol. .

Abstract

Background: Duchenne Muscular Dystrophy (DMD) is a rare X-linked genetic disorder caused by mutations in the dystrophin gene. The North Star Ambulatory Assessment (NSAA) and Performance of Upper Limb (PUL) are used to measure motor performance in ambulatory and non-ambulatory individuals, respectively. There is limited published qualitative evidence on what constitutes a meaningful change on either instrument. The aim of this study is to understand meaningful change in functional abilities as measured by the NSAA and PUL at different ability levels from the perspective of individuals with DMD, caregivers of individuals with DMD, and clinicians.

Methods: The study utilized a non-interventional, descriptive, cross-sectional qualitative design consisting of 69 semi-structured interviews, including individuals with DMD (n = 18), caregivers of individuals with DMD (n = 51), and neuromuscular physiotherapists (n = 2) to understand meaningful change on the NSAA and PUL.

Results: The results for both instruments indicated that: (i) items that are meaningful differ based on ability level; (ii) maintaining function in lower and upper limbs is the ultimate goal; (iii) meaningful change is often reported in relation to gain or loss of specific function, as opposed to number of total points on the scale; and (iv) losing one scale point corresponds to either a partial or full loss in function and activity, which has differing impacts on daily life.

Conclusion: The perception of meaningful change in DMD as measured by the NSAA is influenced by ability levels and ambulatory function, with participants describing their need to maximize certain abilities, maintain function, and retain independence. For the PUL, participants underscored the importance of maintenance of their functional abilities, and highlighted key themes related to maintaining independence in ADLs, reaching, eating/drinking, and finger function for technology use across score categories.

Keywords: Duchenne Muscular Dystrophy; meaningful change; patient-reported outcomes; qualitative research; rare disease.

PubMed Disclaimer

Conflict of interest statement

TC, ED, and AMu are employed by F. Hoffman-La Roche, who funded this study, and were involved in the study design, decision to publish, and preparation of the manuscript. AG, LB, JM, PH, KP, BE, GV, and SC are employees of Modus Outcomes, which received payment from Roche to conduct this research and provide medical writing support. AMa also received payment from Roche to be involved in this research. AJ is an employee of Duchenne UK. The reviewer LA declared a past co-authorship/collaboration with the authors TC and AM.

Figures

Figure 1
Figure 1
NSAA ability scores and associated themes.
Figure 2
Figure 2
Impacts of maintenance associated with NSAA items.
Figure 3
Figure 3
PUL ability scores and associated themes.
Figure 4
Figure 4
Impacts of maintenance associated with PUL items.
See this image and copyright information in PMC

References

    1. Bushby K, Finkel R, Birnkrant DJ, Case LE, Clemens PR, Cripe L, et al. Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and pharmacological and psychosocial management. Lancet Neurol. (2010) 9:77–93. doi: 10.1016/S1474-4422(09)70271-6, PMID: - DOI - PubMed
    1. Darras BT. Duchenne and Becker muscular dystrophy: Management and prognosis In: Patterson MC, Firth HV, editors. UpToDate. Philadelphia, PA: Wolters Kluwer; (2022)
    1. Ryder S, Leadley RM, Armstrong N, Westwood M, de Kock S, Butt T, et al. The burden, epidemiology, costs and treatment for Duchenne muscular dystrophy: an evidence review. Orphanet J Rare Dis. (2017) 12:79. doi: 10.1186/s13023-017-0631-3, PMID: - DOI - PMC - PubMed
    1. Yiu EM, Kornberg AJ. Duchenne muscular dystrophy. Neurology India. (2008) 56:236. doi: 10.4103/0028-3886.43441, PMID: - DOI - PubMed
    1. van Ruiten HJA, Straub V, Bushby K, Guglieri M. Improving recognition of Duchenne muscular dystrophy: a retrospective case note review. Arch Dis Child. (2014) 99:1074–7. doi: 10.1136/archdischild-2014-306366, PMID: - DOI - PMC - PubMed

LinkOut - more resources