Evans, Christopher J.

Abstract Objective This study explores and documents the patient experience during the prodrome phase of migraine. Background Migraine attacks can be divided into four stages: the prodrome (or premonitory phase), the aura, the headache phase, and postdrome. Qualitative data on the range of symptoms during the prodrome and their timing relative to headache onset are sparse. Prodromal symptoms may predict the onset of migraine headache pain and provide a clinically useful benchmark for initiation of treatment early in an attack before pain begins. Design/Methods Eligible participants with a clinician‐confirmed diagnosis of migraine and at least one prodromal symptom were consented, screened, and then participated in 60‐min interviews. The interview guide included open‐ended questions to elicit spontaneous reports and specific probes about prodromal symptoms based on a clinician‐established list. A theory approach was used to analyze the qualitative data collected in interviews to identify key themes and gather insights; data were analyzed using ATLAS.ti. Results Data collection for this study occurred from March 8, 2022, to May 16, 2022. Twenty interviews were conducted, and analyses demonstrated that concept saturation was achieved. Participants reported 36 unique prodromal symptoms, and each participant experienced a mean of 13 symptoms (standard deviation [SD] = 6.6) and a median of 11 symptoms (interquartile range [IQR] = 7.8–17.0) during the prodrome phase. The most commonly reported prodromal symptoms were nausea ( n = 17/20, 85%), fatigue/tiredness ( n = 16/20, 80%), sensitivity to light ( n = 13/20, 65%), neck pain/stiffness ( n = 12/20, 60%), and dizziness/vertigo/light‐headedness ( n = 10/20, 50%). Of the symptoms reported by at least four participants ( n ≥ 4/20, 20%), neck pain/stiffness was rated most bothersome (8.9 out of 10) and sensitivity to light was rated most severe (8.5 out of 10). Almost 40% of all symptoms reported occurred less than 2 h before the start of migraine headache. Of the commonly reported symptoms, nausea (0.8h), sensitivity to light (1.0 h), and dizziness/vertigo/lightheadedness (2.0 h) began closest to headache onset; fatigue/tiredness (4.0 h) and neck pain/stiffness (4.8 h) were the most remote from headache onset. Conclusion This study identified frequently reported prodromal symptoms, with participants commonly reporting that a migraine headache would follow their experience of prodrome within a 1‐ to 6‐h window. Characterizing the prodrome experience may improve measurement strategies for the burden of migraine and create opportunities to treat during the prodromal phase to prevent the onset of moderate or severe headaches.

Abstract Objective To evaluate the content validity and psychometric properties of the Activity Impairment in Migraine Diary (AIM‐D). Background Measuring treatment effects on migraine impairment requires a psychometrically sound patient‐reported outcome (PRO) measure developed consistent with U.S. Food and Drug Administration guidance. Methods The AIM‐D was created from concepts that emerged during qualitative interviews with five clinicians experienced in treating migraine and concept elicitation (CE) interviews with 40 adults with episodic migraine (EM) or chronic migraine (CM). The initial version was refined based on three waves of cognitive interviews with 38 adults with EM or CM and input from a panel of clinical and measurement experts. The AIM‐D was psychometrically evaluated using data from 316 adults with EM or CM who participated in a 13‐week prospective observational study. Study participants completed PRO assessments including the AIM‐D and a daily headache diary. Exploratory and confirmatory factor analysis were used to determine the factor structure. The reliability, validity, and responsiveness of the AIM‐D were assessed. Additional PRO measures including the Patient Global Impression – Severity (PGI‐S), Migraine Specific Quality of Life Questionnaire, Version 2.1 Role Function‐Restrictive domain, and Headache Impact Test were used for psychometric evaluation of the AIM‐D. Results Based on CE interviews with adults with migraine and input from an expert panel, activity impairment was identified as the target in the preliminary conceptual framework, which had two domains: performance of daily activities (PDAs) and physical impairment (PI). Revision of the draft AIM‐D through multiple rounds of cognitive interviews and expert panel meetings resulted in a content valid 11‐item version. Exploratory factor analysis supported both one‐ and two‐domain structures for the AIM‐D, which were further supported by confirmatory factor analysis (factor loadings all >0.90). The AIM‐D domains (PDA and PI) and total score showed high internal consistency reliability (Cronbach's alpha 0.95–0.97), acceptable test–retest reliability for weekly average scores (intraclass correlation coefficient >0.60 for participants with no change in PGI‐S between baseline and week 2), and good convergent and known‐groups validity. There was evidence of responsiveness based on changes in PGI‐S score and monthly migraine days. Conclusion The AIM‐D is a content valid and psychometrically sound measure designed to evaluate activity impairment and is suitable for use in clinical trials of preventive treatments for EM or CM.