Department of Pulmonology, Centro Hospitalar Trás-os-Montes e Alto Douro, Avenida da Noruega, Vila Real, Portugal,
Institute for Research and Innovation in Health (i3S), University of Porto, Rua Alfredo Allen, Porto, Portugal,
Neuroepidemiology. 2019;53(1-2):73-83. doi: 10.1159/000499485. Epub 2019 May 22.
Amyotrophic lateral sclerosis (ALS) is a rare and progressive neurodegenerative disease involving the upper and lower motor neurons. It is also the most common and the one with the worst prognosis among the motor neuron diseases (MND). ALS invariably progresses to respiratory failure, which is an essential factor affecting the prognosis of this disease. Its prevalence in the world is heterogeneous and, in many countries, is even unknown, since national registries are not mandatory or comprehensive enough. Worldwide, the ALS/MND prevalence is estimated between 4 and 8 cases per 100,000 inhabitants, but in Portugal the prevalence was never studied. Because ALS and MND are rare diseases, population-based studies are very difficult to perform. In Portugal, there are no systematic patient registries.
We aimed to obtain the best available indirect estimates of ALS/MND prevalence, using a pharmaco-epidemiological approach.
We developed a Bayesian multiparameter evidence synthesis model based on nationwide data of riluzole consumption, a drug highly specific for ALS/MND, combined with data from a nationwide hospital administrative database, data from the national institute of statistics, and data from other scientific articles focused on ALS/MND epidemiology, to estimate ALS/MND prevalence in Portugal.
We found an estimated ALS/MND prevalence in Portugal steadily increasing from 6.74 per 100,000 inhabitants (Bayesian 95% Credible Interval [95% CI] 5.39-9.37) in 2009 to 10.32 (95% CI 8.27-14.27) in 2016. In 2016, the estimated ALS/MND prevalence was higher in men, 12.08 per 100,000 (9.66-17.15), than in women, 8.56 (6.84-12.32). Regarding age groups, the estimated prevalence per 100,000 inhabitants were, in 2016 for women, 1.19 (0.78-1.85) for the <50 years' group, 8.48 (6.00-12.76) for the 51-60 group, 23.47 (18.05-33.88) for the 61-70 group, 28.77 (22.02-41.31) for the 71-80 group, and 14.45 (9.97-21.63) for the >80 group. For men, the prevalence estimates were 1.90 (1.32-2.84), 12.89 (9.44-19.16), 32.18 (24.91-45.74), 48.85 (38.72-71.40), and 31.27 (21.73-46.41), respectively, for each age group. We also observed a relevant variability across the country, with prevalence estimates, in 2016, of 9.31 cases per 100,000 inhabitants (7.45-12.86) in the Northern region of Portugal, 11.15 (8.9-15.34) in the Centre region, 10.74 (8.6-14.82) in Lisbon and Alentejo regions, and 5.55 (4.35-7.83) in the Algarve region.
Overall, and even though we must account for the limitations of the indirect methods and models used for prevalence estimation, we probably have a very high ALS/MND prevalence in Portugal. It would be important to create registries, particularly in rare diseases, for better organization and distribution of healthcare services and resources, particularly at the level of ventilatory support.
肌萎缩侧索硬化症（ALS）是一种罕见的进行性神经退行性疾病，涉及上下运动神经元。它也是运动神经元疾病（MND）中最常见和预后最差的一种。ALS 不可避免地会发展为呼吸衰竭，这是影响该疾病预后的一个重要因素。它在世界范围内的流行情况各不相同，在许多国家，由于国家登记处没有强制性或不够全面，甚至还不知道。全世界 ALS/MND 的患病率估计在每 10 万人中有 4 到 8 例，但葡萄牙从未对此进行过研究。由于 ALS 和 MND 是罕见疾病，因此很难进行基于人群的研究。在葡萄牙，没有系统的患者登记处。
我们旨在使用药物流行病学方法获得 ALS/MND 患病率的最佳间接估计值。
我们开发了一个基于全国性利鲁唑消费数据的贝叶斯多参数证据综合模型，利鲁唑是一种高度特异性的 ALS/MND 药物，结合全国性医院行政数据库的数据、国家统计局的数据以及其他专注于 ALS/MND 流行病学的科学文章的数据，以估计葡萄牙的 ALS/MND 患病率。
我们发现，2009 年至 2016 年期间，葡萄牙的 ALS/MND 患病率稳步上升，从每 10 万人 6.74 例（贝叶斯 95%可信区间 [95%CI] 5.39-9.37）上升至每 10 万人 10.32 例（95%CI 8.27-14.27）。2016 年，男性的 ALS/MND 患病率高于女性，男性为每 10 万人 12.08 例（9.66-17.15），女性为每 10 万人 8.56 例（6.84-12.32）。在年龄组方面，2016 年，女性的估计患病率为每 10 万人 1.19 例（0.78-1.85），<50 岁组为 8.48 例（6.00-12.76），51-60 岁组为 23.47 例（18.05-33.88），61-70 岁组为 28.77 例（22.02-41.31），>80 岁组为 14.45 例（9.97-21.63）。对于男性，患病率估计值分别为每 10 万人 1.90 例（1.32-2.84）、12.89 例（9.44-19.16）、32.18 例（24.91-45.74）、48.85 例（38.72-71.40）和 31.27 例（21.73-46.41）。我们还观察到全国范围内存在显著的变异性，2016 年，葡萄牙北部地区的患病率估计值为每 10 万人 9.31 例（7.45-12.86），中心地区为每 10 万人 11.15 例（8.9-15.34），里斯本和阿连特茹地区为每 10 万人 10.74 例（8.6-14.82），阿尔加维地区为每 10 万人 5.55 例（4.35-7.83）。
总体而言，尽管我们必须考虑到用于患病率估计的间接方法和模型的局限性，但我们在葡萄牙可能有非常高的 ALS/MND 患病率。重要的是要建立登记处，特别是在罕见疾病方面，以便更好地组织和分配医疗保健服务和资源，特别是在呼吸机支持方面。
