Measurement of Fatigue in Sickle Cell Disease:A Systematic Review of Fatigue Measures

Background : Sickle cell disease (SCD) is a chronic inherited blood disorder caused by abnormal haemoglobin production, affecting over seven million people worldwide. Although pain - particularly acute bone pain - is the hallmark symptom of this disease, fatigue is also a commonly observed manifestation. Fatigue is a debilitating symptom in Sickle Cell Disease (SCD) that significantly impacts quality of life. Accurate assessment of fatigue is crucial for effective disease management. However, a comprehensive analysis of fatigue assessment tools in SCD research is lacking. Objective : This systematic literature review aims to identify and evaluate self-reported psychometric measures of fatigue used in SCD research with children, adolescents, young adults and adults. Methods : A systematic search was conducted across six databases from 2010 to March 2024. The main inclusion criteria included peer-reviewed journal articles, patients with all SCD genotypes, studies evaluating fatigue using a self-reported psychometric measure, and studies published in English or French. The PRISMA guidelines were followed for study selection and data extraction. Results : Twenty-eight studies met the inclusion criteria, reporting on 16 psychometric measures of fatigue. The most frequently used tool was the PROMIS system. Nine dimensions of fatigue were identified, including general, physical, mental, cognitive, emotional fatigue, and its impact on motivation, activity, vigour, and sleep/rest. However, the definitions of these dimensions were often unclear. Reported fatigue scores are not directly comparable due to methodological issues and variability in the assessment used. These methodological issues limit our knowledge on the prevalence of fatigue in SCD. Conclusion : The lack of a standardised fatigue assessment tool in SCD research hinders direct comparison of fatigue scores across studies. Future research should prioritise the development of a tailored assessment tool for SCD, considering the specific dimensions of fatigue relevant to this population. In the interim, clinicians and researchers can employ a combination of multidimensional and unidimensional tools to gain a more comprehensive understanding of patients' fatigue experiences.