The Lithuanian multiple sclerosis registry: current framework and quality challenges.

Objectives: This article presents the current structure, data collection methods, coverage, and limitations of the Lithuanian Multiple Sclerosis (MS) Registry. Materials and methods: The Lithuanian MS Registry, established by the Lithuanian Neurologists' Association, began its activities in 2013. All three national centers providing MS treatment in Lithuania have secure access to their respective patient data and can enter new clinical information into the registry. Adult individuals with a suspected or confirmed diagnosis of MS who receive care in Lithuania and provide written informed consent are eligible for inclusion in the Multiple Sclerosis Patient Surveillance System registry. For the present analysis, a dataset comprising all records from February 1, 2013, to January 1, 2024, was extracted on June 17, 2024. Results: The registry collects individual data on demographics, results from specific diagnostic procedures (such as cerebrospinal fluid analysis, evoked potentials), clinical evaluations conducted at every visit (based on the Expanded Disability Status Scale), treatment, and relapses (including their dates and whether corticosteroid treatment was administered). Currently, the registry includes 2,923 patients. Of these, 1,651 patients are classified as in active follow-up (those with at least one recorded visit since January 1, 2021) and represent less than half of the total MS population in Lithuania (47.3%). The registry covers approximately 69.5%-74.6% of all patients receiving disease-modifying therapy in the country. Conclusion: Although the registry has been operating for more than a decade, challenges remain in patient enrollment and ensuring high-quality data collection. Strengthening validation processes is essential to ensure the registry's reliability and utility in both clinical practice and research settings.