Definition of fibromyalgia severity: findings from a cross-sectional survey of 2339 Italian patients

Abstract Objective To establish optimal cut-off values for the scores of the revised Fibromyalgia Impact Questionnaire (FIQR), the modified Fibromialgia Assessment Scale (FAS 2019mod), and the Polysymptomatic Distress Scale (PDS) in order to distinguish five levels of FM disease severity. Methods Consecutive FM patients were evaluated with the three clinimetric indices, and each patient was required to answer the anchor question: ‘In general, would you say your health is 1 = very good, 2 = good, 3 = fair, 4 = poor, or 5 = very poor?’—which represented the external criterion. Cut-off points were established through the interquartile reconciliation approach. Results The study sample consisted…