Supplementary Material for: INCIDENCE OF MULTIPLE SCLEROSIS IN URUGUAY. A PROSPECTIVE POPULATION-BASED STUDY

Background
The worldwide incidence of multiple sclerosis (MS) is estimated at 0.5-10 cases per 100,000 person-years and is probably increasing. In 2014, a previous study estimated the incidence of multiple sclerosis in Uruguay at 1.2 cases per 100.000 person-years.

Objectives
We conducted an observational, prospective, population-based study to determine MS incidence from diagnosis in Uruguay.

Methods
The population studied included people older than 18 years of age, who were living in Uruguay between July 1, 2019, and June 30, 2021. The diagnosis was based on 2017 McDonald criteria. Multiple data sources were employed including neurologists, magnetic resonance imaging centers, laboratories performing oligoclonal band testing, neurophysiology laboratories, neurorehabilitation centers, the institution Fondo Nacional de Recursos, and the MS Patients’ Association of Uruguay (EMUR). The capture-recapture method was used to estimate incidence.

Results
155 new MS cases were confirmed after review. The median age was 35 (range 18-62). Thirteen patients (8.38%) were diagnosed with late onset MS.
The crude incidence rate was 2.89 cases per 100,000 person-years, 3.95 among female and 1.72 among male patients. The incidence rate estimated using the capture-recapture method was 3.18 (95% CI 3.02-3.34).

Conclusions
According to the Atlas of MS, Uruguay has a low incidence rate (2.0-3.99), even though it is one of the highest in Latin America. Our country aligns with the global trend of increasing incidence. Age and sex distribution were similar to other studies, with a high incidence of patients with late onset multiple sclerosis. The capture-recapture method confirms the exhaustivity of our investigation.

研究背景
全球范围内多发性硬化（multiple sclerosis, MS）的发病率估计为每10万人年0.5~10例，且大概率呈上升趋势。2014年，一项既往研究估计乌拉圭的多发性硬化发病率为每10万人年1.2例。

研究目的
本研究开展了一项基于人群的观察性前瞻性研究，旨在明确乌拉圭地区经确诊的多发性硬化发病率。

研究方法
本研究的研究对象为2019年7月1日至2021年6月30日期间居住在乌拉圭的18岁以上人群。诊断标准采用2017版McDonald标准（McDonald criteria）。本研究整合多源数据渠道，包括神经科医师、磁共振成像中心、开展寡克隆带检测的实验室、神经生理学实验室、神经康复中心、国家资源基金（Fondo Nacional de Recursos）以及乌拉圭多发性硬化患者协会（EMUR）。研究采用捕获-再捕获法（capture-recapture method）估算发病率。

研究结果
经审核后共确认155例新发多发性硬化病例。患者中位年龄为35岁（年龄范围18~62岁），其中13例（8.38%）被诊断为晚发型多发性硬化。
粗发病率为每10万人年2.89例，其中女性为3.95例，男性为1.72例。采用捕获-再捕获法估算的发病率为3.18（95%置信区间：3.02~3.34）。

研究结论
据《多发性硬化图谱》（Atlas of MS）显示，乌拉圭的多发性硬化发病率处于低水平区间（2.0~3.99/10万人年），即便如此，其发病率仍是拉丁美洲最高的地区之一。乌拉圭的发病率变化趋势符合全球上升的整体态势。本研究中患者的年龄与性别分布与其他同类研究相似，且晚发型多发性硬化患者占比偏高。捕获-再捕获法证实了本次调查的穷尽性。