Assessing attack-related fear in headache disorders-Structure and psychometric properties of the Fear of Attacks in Migraine Inventory.

Objective: This study aimed to develop a self-report questionnaire for the assessment of attack-related fear in migraine, and to determine its factor structure as well as its psychometric properties by the primary analysis of a cross-sectional survey's data.

Background: High fear of attacks in migraine increases the burden of disease and is assumed to have a negative impact on the course of the disease. Little is known about the structure and dimensionality of attack-related fear, and a valid instrument for the comprehensive assessment is lacking.

Methods: Based on a literature search and interviews with persons with migraine as well as with experienced practitioners, a 46-item self-report questionnaire, the Fear of Attacks in Migraine Inventory (FAMI) was developed. A cross-sectional online survey comprising an assessment of diagnostic criteria of migraine and a battery of questionnaires including the FAMI was conducted (N = 387 persons with migraine, 364/387 [94.1%] women, M = 40.9 [SD = 13.1] years, migraine without aura: 153/387 [39.5%], migraine with aura: 85/387 [22.0%], and chronic migraine: 149/387 [38.5%]).

Results: Item selection led to 29 items for the FAMI. Exploratory factor analysis resulted in three clearly interpretable factors (fear of negative consequences; attention and anticipation; fear-avoidance); a confirmatory factor analysis yielded an acceptable to good model fit (χ (3) = 1328.84, p = 0.001, χ /df = 3.55, RMSEA = 0.085, SRMR = 0.073, CFI = 0.98, and TLI = 0.97). Reliability was good (fear-avoidance, ω = 0.85; attention and anticipation, ω = 0.88) to excellent (fear of negative consequences, ω = 0.91). Correlational analyses confirmed the convergent validity of the FAMI.

Conclusions: The FAMI appears suitable and promising for the assessment of attack-related fear in migraine research and clinical care.