Toward the Optimal Way to Assess Symptomatic Fatigue in Degenerative Cervical Myelopathy: Mixed Methods Survey Study

Background Recent work has demonstrated that individuals with degenerative cervical myelopathy (DCM) often experience symptoms of fatigue that are underrepresented in the literature. Conversely, understanding fatigue is highly important to people living with DCM. The AO Spine RECODE-DCM (Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy) study group recently determined that no suitable fatigue scales exist for DCM. Objective An assessment of content validity of existing fatigue scales used in other populations was undertaken to determine whether any such scales are suitable for DCM. Methods An expert panel of people with DCM was convened. The panel comprised members of the RECODE-DCM steering committee, and their DCM ranged in severity from mild to severe; all resided in the United Kingdom or the United States. They were presented with 19 instruments in use for other pathologies and developed a quantitative description of relevance to DCM. The committee scored each scale on clarity and comprehensiveness. We conducted a preliminary qualitative analysis of comments on the various attributes of each instrument to establish themes distinguishing high-scoring from lower-scoring instruments. Results The highest-scoring scales were the (1) Modified Fatigue Impact Scale for Spinal Cord Injury (relevance=3.78; comprehensiveness=3.56; clarity=4), (2) Multidimensional Assessment of Fatigue (3.67, 3.56, and 3.89, respectively), and (3) Functional Assessment of Chronic Illness Therapy–Fatigue Scale (3.56, 3.56, and 3.89, respectively). Common themes used in discussing various instruments were sleep, pain, psychosocial factors, and employment. Conclusions The Modified Fatigue Impact Scale for Spinal Cord Injury, Multidimensional Assessment of Fatigue, and Functional Assessment of Chronic Illness Therapy–Fatigue Scale appear to be the most appropriate and validated instruments for assessing fatigue in patients with DCM. These scales demonstrate strong psychometric properties while addressing the unique symptomatic profile and functional limitations characteristic of DCM, enabling more accurate measurement and clinical monitoring of fatigue in this patient population.