Outcome Measures and Quality of Life in Mitochondrial Diseases

  • S. Koene
  • C. Jimenez-Moreno
  • G. S. GormanEmail author


Mitochondrial diseases are a group of rare neurometabolic disorders that are extremely complex, not least due to their clinical and genetic heterogeneity. The management of these patients remains difficult, because there are currently no interventions that provide a realistic prospect of cure. This represents a compelling unmet need. And while this is recognised as a significant challenge, there remains another significant barrier to robustly assess and measure disease status and progression for each patient and to measure potential effects of any potential intervention. The tools and instruments used to quantify clinical aspects of disease and its impact on someone’s life are referred to as outcome measures. Recent efforts have been made to identify the most appropriate outcome measures that can overcome the inherent challenges of mitochondrial disease characteristics, such as clinical heterogeneity, unpredictability of disease progression rate and the spectrum of ages that may be affected. Still, there is a need for further research in the field. The different paradigms of these outcomes may vary in their nature and purpose, but all should agree in the fact that they reflect clinically relevant aspects of the health and quality of life of those affected by the disease. Certain outcomes may be measured by clinicians or researchers, while others may be scored directly by the patients or their proxies. Other outcomes may assess walking ability, while others may assess perceived fatigue or visual acuity; yet any of these endpoints may be equally valid. Indeed, it is most likely that a concise battery of outcomes would most likely capture the most clinically relevant and patient-centric measures. When designing a clinical trial in patients with mitochondrial diseases, it is imperative that all stakeholders involved should understand the relevance of selecting a valid outcome measure that promises to measure the characteristic(s) of the disease in which the intervention is expected to reflect its benefit. This chapter endeavours to review current constructs around the assessment of outcome measures and quality of life that have been used in patients with mitochondrial disease to date and to discuss their potential benefits and limitations.


Mitochondrial disease Outcome measure Endpoint Clinical trial Clinical outcome assessment Quality of life Patient-reported outcome Patient preferences Patient-centred outcomes 


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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Radboud Center for Mitochondrial MedicineNijmegenThe Netherlands
  2. 2.Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK

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