Digging into the construct of fibrofog: Psychometric properties of the Spanish version of the Multidimensional Inventory of Subjective Cognitive Impairment in patients with fibromyalgia

Perceived dyscognition or fibrofog has been ranked as one major contributor of distress in fibromyalgia (FM). The Multidimensional Inventory of Subjective Cognitive Impairment (MISCI) was devised as a brief and comprehensive self-report measure of cognitive function in FM. The main objective of the present study was to assess the psychometric properties of the Spanish version of the MISCI. One hundred and twenty patients with FM were included, and dimensionality, reliability, and validity of the MISCI were evaluated. Data from brain imaging (N = 61) were also used in validity analyses. Known-groups validity was evaluated by including a subset of 45 patients without FM in partial/total remission from depression. Sensitivity to change was assessed after a mindfulness-based intervention. Spanish version of the MISCI exhibited a one-factor structure, excellent internal consistency, and good convergent validity with symptomatology and gray matter volumes in anterior and middle cingulate cortices. Significant improvements in MISCI scores after a mindfulness-based intervention were reported. An additive effect of FM and depression regarding MISCI scores was also observed. Self-reported depression, anxiety, and problems in balance predicted the 38% of the MISCI variance. The Spanish version of the MISCI is a valuable instrument to include in FM research and clinical practice.