Surreal illustration of a person with glowing muscles overlaid with a map of Brazil, representing the blend of personal health and cultural context in myasthenia gravis.

Living Well with Myasthenia Gravis: Adapting Quality of Life Assessments for Brazilians

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Nico Varela in Health & Wellness November 2026 • 4 min read.

"A groundbreaking study adapts the MG-QOL15 questionnaire for Brazilian Portuguese speakers, offering new insights into managing this chronic condition."


Myasthenia Gravis (MG) is a chronic autoimmune neuromuscular disease impacting millions worldwide, including a significant population in Brazil. It causes fatigue and muscle weakness that fluctuates, making daily life unpredictable and challenging. While medical treatments can help manage the symptoms, understanding and addressing the impact of MG on a patient's overall well-being is crucial.

Quality of life (QOL) is a key aspect of managing chronic conditions like MG. It encompasses physical, emotional, and social well-being. Assessing QOL helps healthcare professionals understand the patient's perspective, tailor treatment plans, and provide comprehensive support. Questionnaires designed to measure QOL provide a structured way to capture this information.

Recognizing the need for a culturally relevant tool, researchers in Brazil undertook the task of translating and adapting the "Questionnaire of Life Quality Specific for Myasthenia Gravis - 15 items" (MG-QOL15). This internationally recognized questionnaire provides a concise way to assess the impact of MG on daily life. By adapting it for Brazilian Portuguese speakers, the study aimed to provide a more accurate and meaningful assessment of QOL for this population.

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Measuring Quality of Life in MG

Health-related quality of life is frequently decreased in people with myasthenia gravis. A prospective survey examined quality of life with the myasthenia gravis-specific 15-item Quality of Life scale, MG-QoL15, alongside activities of daily living. The MG-QoL15r is the revised 15-item version, with official information covering licensing, scoring, and translations.

The MG-QoL15r Approach

Patient-reported health scores for symptoms, outcomes, and quality of life have become an integral part of comprehensive disease evaluation and management. The MG-QoL15r is a validated 15-item scale designed to assess important aspects of a patient's experience related to myasthenia gravis. It scores each item from 0 to 2, for a maximum score of 30, whereas the original MG-QoL15 scores items from 0 to 4, for a maximum of 60; some wording was also modified in the revised version.

Why Adapt a Questionnaire for a Specific Culture?

Surreal illustration of a person with glowing muscles overlaid with a map of Brazil, representing the blend of personal health and cultural context in myasthenia gravis.

Generic QOL questionnaires may not fully capture the unique challenges faced by individuals with MG in a specific cultural context. Cultural factors can influence how symptoms are perceived, how healthcare is accessed, and how social support systems operate. Adapting a questionnaire involves more than just translating the words; it requires ensuring that the concepts are understood and relevant within the target culture.

The process of cross-cultural adaptation typically involves several steps, ensuring the translated version accurately reflects the original while being culturally appropriate:

  • Translation: The original questionnaire is translated into the target language (Brazilian Portuguese in this case) by multiple independent translators.
  • Synthesis: The translations are compared and synthesized into a single version.
  • Back-Translation: The synthesized version is translated back into the original language (English) by independent translators who are unaware of the original questionnaire.
  • Expert Review: An expert committee reviews both the original and back-translated versions to identify discrepancies and ensure conceptual equivalence.
  • Cognitive Testing: The adapted questionnaire is tested with members of the target population to assess their understanding and identify any remaining issues.
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Current Validation Research

A 2026 study examined the validation and clinical utility of OMGRate and MG-QOL15 in myasthenia gravis. The MG-QOL15 is described as an internationally recognized tool for assessing quality of life in MG. Its 15 indicators cover psychological and physiological dimensions and systematically evaluate effects on patients' social functioning and emotional status.

Correlation With Functional Measures

The cited study compared MG-QOL15 results with other functional scales used in myasthenia gravis. Its MG-QOL15 score correlated strongly with the Myasthenia Gravis Activities of Daily Living scale and with Neuro-QOL Fatigue. The weakest correlation was reported with the Quantitative Myasthenia Gravis assessment.

The Brazilian study meticulously followed these steps to create a culturally relevant version of the MG-QOL15. This involved not only linguistic translation but also adjustments to ensure the questions resonated with the experiences of Brazilian patients with MG.

What Were the Key Findings and Adaptations?

The Brazilian researchers found that some questions in the original MG-QOL15 were difficult for patients to understand. For example, questions relating to 'professional status' were replaced with 'my position at work' and included the clarification 'cargo' (meaning job function) to improve comprehension. These adaptations highlight the importance of considering cultural context and language nuances when assessing QOL.

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The Personal Burden of MG

Myasthenia gravis is described as a rare, chronic, autoimmune neuromuscular disease that can affect functional and mental aspects of health and health-related quality of life. The patient-reported burden study sought detailed knowledge of MG's impact. This framing emphasizes that assessment should consider both functional health and mental well-being.

How repeatability and other patient groups frame the measure

A registry found moderate-to-severe quality-of-life impairment among most registrants, with a median MG-QOL15 score of 21 alongside a median MG-ADL score of 6. These registry figures describe a different group and do not establish a benchmark for Brazilian Portuguese adaptation.[1]

A Japanese validation involved 327 patients seen at six neurological centers, while a Turkish validation tested translations with healthy individuals and patients with stable MG. These examples show that validation work has been conducted in different settings and populations, but they do not establish equivalence across languages.[2] [3]

The U.S. registry evidence was limited to people living in the United States who enrolled during a specified period, so its results may not represent other populations. Separately, the absence of test-retest reliability data for MG-QOL15R limited calculation of a measurement-error threshold; that qualification concerns the revised scale, not the original scale’s reliability result.[1] [4]

What evidence would clarify scores and change over time

  • How well do MG-QOL15 scores track changes in symptoms or daily functioning over time, given the scale’s reported scoring range and its disease-specific focus?[1]
  • Would repeat measurements of the revised scale establish how much score movement exceeds measurement error, given the reported lack of test-retest data for MG-QOL15R?[4]

Sources

  1. Cross‐sectional analysis of the Myasthenia Gravis Patient Registry: Disability and treatment (pmc.ncbi.nlm.nih.gov)
  2. The MG-QOL15 Japanese version: validation and associations with clinical factors. (pubmed.ncbi.nlm.nih.gov)
  3. "Reliability and validity of the Turkish version of myastheniagravis-qu" by NİDA FATMA TAŞCILAR, ÖZGE SARAÇLI et al. (journals.tubitak.gov.tr)
  4. Estimating the minimal clinically important difference for the Myasthenia Gravis Quality of Life revised scale (MG-QOL15R) (pmc.ncbi.nlm.nih.gov)

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

Everything You Need To Know

1

What exactly is Myasthenia Gravis?

Myasthenia Gravis (MG) is a chronic autoimmune neuromuscular condition where the body's immune system mistakenly attacks the connections between nerves and muscles. This leads to fluctuating muscle weakness and fatigue. While treatments can manage symptoms, understanding the impact on a person's daily life and overall well-being is essential. This is because the severity of MG symptoms can vary greatly, affecting a person's ability to perform everyday tasks and impacting their quality of life.

2

Why is understanding Quality of Life important when dealing with Myasthenia Gravis?

Quality of Life (QOL) is very important in managing Myasthenia Gravis because it captures the broader impact of the disease beyond just the physical symptoms. It considers a person's physical, emotional, and social well-being. Assessing QOL through questionnaires like the MG-QOL15 helps doctors tailor treatment plans to address specific challenges patients face, ultimately improving their overall well-being. If QOL is not considered, treatments may only focus on the physical aspects, neglecting the emotional and social support needed to live well with MG.

3

What is the MG-QOL15 questionnaire?

The MG-QOL15, or "Questionnaire of Life Quality Specific for Myasthenia Gravis - 15 items", is a questionnaire designed to quickly assess the impact of Myasthenia Gravis on a person's daily life. It provides a structured way to measure QOL, helping healthcare professionals understand the patient's perspective and tailor treatment plans accordingly. The MG-QOL15 focuses specifically on the challenges faced by individuals with MG, offering targeted insights compared to generic quality-of-life assessments. However, the MG-QOL15 needs to be adapted for different languages and cultures to ensure it accurately reflects the experiences of diverse patient populations.

4

Why is it necessary to adapt the MG-QOL15 for use in different cultures?

Adapting questionnaires like the MG-QOL15 for different cultures, like in Brazil, is essential because cultural factors can influence how people perceive their symptoms, access healthcare, and receive social support. A direct translation might not capture the nuances of language and cultural context, potentially leading to inaccurate assessments of QOL. This process ensures the questionnaire is both linguistically accurate and culturally relevant, providing a more meaningful understanding of the challenges faced by individuals with MG in a specific cultural context. The cross-cultural adaptation process ensures that the adapted version accurately reflects the original while being culturally appropriate.

5

What does the process of adapting a questionnaire like MG-QOL15 involve?

The adaptation process involves multiple steps: translation by independent translators, synthesis of translations into a single version, back-translation into the original language by independent translators unaware of the original questionnaire, expert review to identify discrepancies and ensure conceptual equivalence, and cognitive testing with members of the target population to assess their understanding and identify any remaining issues. For example, in Brazil, the term 'professional status' in the MG-QOL15 was replaced with 'my position at work' and included the clarification 'cargo' (meaning job function) to improve comprehension. This rigorous process ensures the adapted questionnaire accurately reflects the experiences of individuals with MG in the target culture, enhancing the validity and reliability of QOL assessments.

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