Methodology and baseline characteristics of the China Migraine registry (CHIME): a nationwide, multi-center, prospective cohort study of 11,814 patients

BACKGROUND: Migraine is the leading cause of years lived with disability (YLDs) in young and middle-aged populations globally. Despite strategic initiatives to standardize headache care in China, large-scale real-world evidence regarding clinical management patterns remains sparse. The China Migraine Registry (CHIME) was established to bridge this gap. This study aims to delineate the CHIME methodology and report the baseline clinical characteristics, diagnostic accuracy, and therapeutic patterns of its initial cohort. METHODS: CHIME is a nationwide, multi-center, prospective, longitudinal cohort study involving over 100 specialized headache centers across 28 provinces in China. Initiated in May 2024, the study utilizes a proprietary digital health platform integrated with a clinical decision support system (CDSS 2.0) for headache disorders. Data collection encompasses structured clinical profiles, patient-reported outcomes, and specialized sub-study cores. This baseline analysis details the cross-sectional characteristics of patients enrolled through February 15, 2026. RESULTS: Among 11,814 participants (79.43% female; mean age 37.42 ± 10.94 years), 10,123 (85.7%) had episodic migraine (EM), 1,019 (8.6%) had chronic migraine (CM), and 672 (5.7%) had probable migraine. A profound diagnostic-therapeutic gap was identified: only 31.0% of patients had received a correct prior diagnosis. Paradoxically, 91.43% had undergone auxiliary investigations, primarily cranial imaging (87.36%). Acute treatment relied heavily on non-specific analgesics (NSAIDs: 59.77% EM, 51.03% CM). Among patients meeting clinical criteria for prophylaxis, only 26.59% were receiving preventive therapy, and the treatment maintenance rate was critically low (12.56% for ≥3 months). CM patients exhibited significantly higher disability (MIDAS Grade IV: 52.2% vs. 26.9%) and psychiatric comorbidities compared to EM patients (p < 0.001). CONCLUSIONS: The CHIME study reveals a paradoxical "treatment odyssey" in China characterized by a low correct diagnosis rate, pervasive diagnostic over-investigation, alongside a systemic under-utilization of evidence-based therapies. These findings highlight the urgent need for standardized diagnostic implementation and improved prophylactic maintenance in China's headache care system.