Systematic Review of Patient‐ and Observer‐Reported Outcomes of Fatigue in Pediatric Neuromuscular Disorders

ABSTRACT Fatigue is a burdensome symptom for pediatric populations with neuromuscular disorders, often assessed using patient‐ and observer‐reported outcomes. The three aims of this systematic review are to: (1) explore, summarize and critically appraise primary studies that measure fatigue in pediatric neuromuscular disorders using patient‐ and observer‐reported outcomes; (2) compare definitions of fatigue and related terms presented within these studies; and (3) summarize evidence for validation of patient‐ and observer‐reported outcomes used in included studies. Six electronic databases were searched. Of 6801 studies identified, 64 met the inclusion criteria of measuring fatigue with a patient‐ and/or observer‐reported outcome and investigated populations below 22 years of age with neuromuscular disorders. Fatigue assessments included questionnaires (80%), interviews/testimonials (17%), and single‐item measures (3%). To measure fatigue, 50% of studies used 1 questionnaire, 28% used 2 or more questionnaires, 6% used interviews alone, 3% used single‐item measures alone, and 13% used a combination of these methods. Quality appraisal indicated 80% of included studies had moderate–high risk of bias. Of all included studies, 10 employed varying definitions of fatigue or related terms. Fatigue was commonly described as an overwhelming, multidimensional and whole‐body experience. Several questionnaires used to measure fatigue were developed to measure other constructs such as quality of life. Evidence for psychometric validation of all questionnaires was limited, and evidence for validation in neuromuscular disorders and pediatric populations was scarce. This review indicates a need for coherent and standardized fatigue definitions and measures while highlighting the scarcity of evidence for validation of frequently used questionnaires.