China Dizziness and Vertigo Cohort Study （VERIDICAL STUDY）

This study is designed as a prospective, multicenter, real-world observational registry based on the Chinese Headache and Vertigo Registry System (CHRS), aiming to systematically characterize the etiological spectrum, diagnostic evolution, and clinical outcomes of patients presenting with dizziness and/or vertigo across neurology and otolaryngology outpatient settings in China. Participants will be consecutively or randomly enrolled from approximately 69 hospitals across more than 30 provinces, and all clinical data will be collected using standardized electronic case report forms within the CHRS platform. The registry integrates structured baseline assessments, including demographic characteristics, detailed clinical history, neurological and otological examinations, and standardized vestibular and audiological investigations, as well as validated patient-reported outcome measures. Etiological classification will be performed according to the Bárány Society International Classification of Vestibular Disorders consensus criteria, with supplementary classification based on ICD-11 when necessary. Longitudinal follow-up will be conducted at predefined time points up to 12 months, with extended follow-up allowed when clinically indicated, to evaluate diagnostic stability, symptom evolution, treatment response, and functional outcomes under routine clinical practice.

A comprehensive data management and quality assurance framework will be implemented. The CHRS registry will incorporate predefined data validation rules, including range checks, logical consistency checks, and cross-variable verification to ensure internal data integrity. Source data verification will be performed through periodic comparison of registry entries with medical records, imaging reports, and original clinical documentation at participating sites. A detailed data dictionary will be maintained, defining each variable, coding standards (including internationally recognized terminologies where applicable), and measurement scales. Standard Operating Procedures (SOPs) will govern all aspects of registry operations, including patient recruitment, informed consent, data entry, follow-up procedures, adverse event reporting, data monitoring, and protocol amendments. Site monitoring and auditing will be conducted periodically by independent reviewers to ensure protocol adherence and data accuracy.

Missing data will be managed according to predefined rules, including documentation of missingness mechanisms (e.g., unavailable, non-reported, or out-of-range values), and handled using appropriate statistical techniques such as multiple imputation or sensitivity analyses when applicable. Sample size determination is based on expected prevalence estimates and study precision requirements, with planned enrollment of approximately 6,000 participants to ensure adequate statistical power and representativeness. A detailed statistical analysis plan will be implemented, specifying descriptive analyses, comparative analyses, longitudinal modeling, and regression-based approaches to address primary and secondary objectives. All analyses will be conducted using validated statistical software, and results will be reported in accordance with relevant guidelines for observational registry studies.

Primary outcomes

• Proportion of patient number with specific etiology of vestibular diseases [In every research point of follow-up, and the extended follow-up period]: For this outcome measure, we will calculate the proportion for the number of patients in each confirmed etiology of vestibular disease among the enrolled patient population or total patient count during a specific follow-up time
• Proportion of patients with moderate-to-severe vestibular symptoms improving to mild severity [In each time point to follow up within 12 months from study enrolment and during the extended follow-up phase. This proportion may be calculated for the same follow-up time period when rescue medication is administered.]: Defined as the proportion of patients from whom their moderate-to-severe vestibular symptoms improve to mild severity within the specified time window after administration of appropriate first-line acute-phase therapeutic agents selected in accordance with recommendations from disease-specific treatment guidelines.
• Reduction in days with vestibular symptoms relative to baseline vestibular symptom days [Every follow-up time point of the research]: The numeric reduction in the average number of days with vestibular symptom episodes during follow-up time point after a period of preventive treatment, compared with baseline.
• Reduction in frequence of vestibular symptom episode relative to baseline vestibular symptom frequence [Every follow-up time point of the research]: The numeric reduction in the average number of frequence with vestibular symptom episodes during follow-up time point after a period of preventive treatment, compared with baseline.
• Number of rescue-medication administrations during preventive treatment [Every follow-up time point of the research]: Number of rescue medications required for recurrent vestibular symptom episodes while on preventive medication.

Secondary outcomes

• Number of one more subsequent rescue-medication administrations after initial acute treatment [Every follow-up time point of the research]: Calculation the number of subsequent rescue medication administration after initial acute treatment to evaluate the efficiency of specific treatment drug
• The proportion of patient number whom whose moderate to severe vestibular symptom relieved completely [In each specific follow-up time point]: Calculation the proportion of patient number whom whose moderate to severe vestibular symptom relieved completely among all the patient population after initial acute drug therapy
• Time to full functional recovery after one vestibular symptom attack [In each follow-up time point]: Calculation the time window for the first rescue medication until patients achieve full recovery of abilities for daily living and work, this secondary outcome is also used to evaluate the efficiency of one specific acute therapy
• Reduction in scale scores related to vestibular symptoms and their associated symptoms compared to baseline scale scores [Within the time window of a single acute vestibular symptom episode and in each follow-up time]: calculate numeric improvement in scale scores related to vestibular symptoms and their associated symptoms relative to baseline scores following acute treatment.
• The number of healthcare burden associated with vestibular disease-related diagnosis and treatment within 1-year follow-up [The research end point in 12-month follow-up time point]: Healthcare costs, transportation expenses, work-loss costs and other expenses incurred for the diagnosis and treatment of vestibular disease during the 1-year follow-up period.
• The number of different adverse reactions related to any each of study treatment medication [In each follow-up time point from study enrolment until study termination.]: Adverse reactions associated with administered therapeutic agents occurring in patients who receive pharmacological treatment following study enrolment.
• The number of patients who keep using the prescribed preventive treatment medication [From initiation of preventive treatment until discontinuation of the preventive]: We calculate the proportion of patients continuing preventive medication during follow-up, care about the retention rate of each prophylactic drug

Sex: All, ages: 6 Years to 100 Years

Inclusion Criteria:

* Participants must meet all of the following criteria:a) Age between 18 and 65 years, inclusive;b) Male or female;c) Consecutive patients presenting to dizziness/vertigo outpatient clinics in the Departments of Neurology or Otolaryngology at 69 hospitals across more than 30 provinces in China, with symptoms of spatial orientation impairment or balance disturbance, including vertigo, dizziness, vestibular-visual symptoms, and postural symptoms;d) Ability and willingness to provide written informed consent

Exclusion Criteria:

* Inability to cooperate with essential diagnostic procedures, including medical history collection, physical examination, laboratory investigations, or other required evaluations, resulting in failure to establish a basic clinical diagnosis;b) Refusal or inability to provide written informed consent.

• Ruthberg JS, Rasendran C, Kocharyan A, Mowry SE, Otteson TD. The economic burden of vertigo and dizziness in the United States. J Vestib Res. 2021;31(2):81-90. doi: 10.3233/VES-201531. PMID 33285661
• Xing Y, Si L, Zhang W, Wang Y, Li K, Yang X. Etiologic distribution of dizziness/vertigo in a neurological outpatient clinic according to the criteria of the international classification of vestibular disorders: a single-center study. J Neurol. 2024 May;271(5):2446-2457. doi: 10.1007/s00415-023-12166-3. Epub 2024 Jan 17. PMID 38231268

• Kaiming Liu, Doctor, Principal investigator, Second Affiliated Hospital, Zhejiang University, School of Medicine