Background <p>Amyotrophic Lateral Sclerosis (ALS) is a rapidly progressive, life-limiting neurodegenerative disease. Informal carers provide extensive support, significantly impacting their health-related quality of life (HRQoL). Current HRQoL measurement using person-reported outcome measures (PROMs) in ALS carers lacks consistency and comprehensiveness, hindering robust assessment and synthesis. There is evident need for a comprehensive conceptual framework of HRQoL, to fully capture the multidimensional nature of caregiving in ALS. Such a framework is essential to inform research and clinical practice, ensuring relevant measurement and meaningful clinical discussions. This study aimed to develop this evidence-based framework.</p> Methods <p>This study comprised two stages. Firstly, a scoping review was undertaken in March 2024 using Medline, Embase, and CINAHL to identify primary articles exploring HRQoL in ALS carers. Qualitative, mixed methods and quantitative articles using multi-item PROMs to assess HRQoL in informal ALS carers were included. Relevant themes and subthemes were extracted from articles and PROMs and mapped onto an existing conceptual framework for people with ALS (Quality of Life in ALS, QuALS), which covers physical, psychological, and social HRQoL domains in people with ALS. The Carer-QuALS framework was subsequently developed and refined using existing literature and consultation with ALS carers. PROMs within this review were then indexed against the finalised Carer-QuALS framework.</p> Results <p>From 715 search results, 82 articles and 44 PROMs were eligible for inclusion. One new subtheme ‘physical caring activities’ emerged, while seven subthemes lacked support from the literature. In three structured consultation sessions, nine ALS carers, reviewed the draft Carer-QuALS framework (consisting of seven themes and 43 subthemes). Based on their input, one new subtheme ‘privacy’ was added, six subthemes were removed, and one was retained, despite lacking support from review literature. The final Carer-QuALS framework includes 37 subthemes: 8 physical, 6 social, and 23 psychological.</p> Conclusions <p>This review presents a comprehensive conceptual framework encompassing the multidimensional impact of ALS caregiving on the HRQoL of informal carers. The framework provides a resource that can be used by researchers, clinicians, and patient advocacy groups for multiple purposes (e.g., to support PROM selection to measure HRQoL, to guide future PROM development, and to facilitate discussions between informal carers and clinicians).</p>