Psychometric properties of the Multidimensional Assessment of Fatigue scale in traumatic brain injury: an NIDRR Traumatic Brain Injury Model Systems study.

ABSTRACT

OBJECTIVE: To investigate the psychometric properties of the Multidimensional Assessment of Fatigue (MAF) scale in a traumatic brain injury (TBI) sample. DESIGN: Prospective survey study. SETTING: Community. PARTICIPANTS: One hundred sixty-seven individuals with TBI admitted for inpatient rehabilitation, enrolled into the TBI Model Systems national database, and followed up at either the first or second year postinjury. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S) Multidimensional Assessment of Fatigue. RESULTS: The initial analysis, using items 1 to 14, which are based on a 10-point rating scale, found that only 1 item ("walking") misfit the overall construct of fatigue in this TBI population. However, this 10-point rating scale was found to have disordered thresholds. When ratings were collapsed into 4 response categories, all MAF items used to calculate the Global Fatigue Index formed a unidimensional scale. CONCLUSION(S) Findings generally support the unidimensionality of the MAF when used in a TBI population but call into question the use of a 10-point rating scale for items 1 to 14. Further study is needed to investigate the use of a 4-category rating scale across all items and the fit of the "walking" item for a measure of fatigue among individuals with TBI.