With rising life expectancy and advancements in disease management, we expect the multiple sclerosis population is getting older. However, evidence supporting this hypothesis remains sparse. Our study aimed to determine whether the mean age of the Danish multiple sclerosis population has increased and to analyse the developments in sex distribution, incidence and prevalence, all of which affect age composition. We conducted a cohort study by linking nationwide data from the Danish Multiple Sclerosis Registry to the Population Statistics Registry, the Danish Cause of Death Registry, and the Historical Migration Registry. We included all living patients with a confirmed multiple sclerosis diagnosis who lived in Denmark on the 1st of January each year from 1950 to 2023. We calculated the mean and median age, age distribution, sex distribution, incidence and prevalence of the Danish multiple sclerosis population annually from 1950 to 2023. We included 28 145 individuals with multiple sclerosis. The mean age of the Danish multiple sclerosis population increased until the late 1970s to ∼52.5 years, where it stabilized until 1990. The mean age experienced a slight decline to 51.2 years in 2005, followed by a subsequent rise to its peak of 54.2 years in 2023. In 1975, females comprised 58.7% of the multiple sclerosis population, increasing to 65.7% by 2000 and 68.5% in 2023. The incidence of multiple sclerosis remained stable at ∼3.5 per 100 000 until 1975 and steadily increased by more than three times in 2000 to 11.4 per 100 000. Despite fluctuations, it remained relatively stable from 2000 until 2022, showing a slight decrease in 2022 compared to the previous two decades. Both overall and sex-specific prevalence exhibited an upward trend, particularly among females. Our study demonstrates that the mean age of the Danish multiple sclerosis population has increased, although not as decisively as expected. The female proportion has grown in tandem with prevalence, while incidence appears to have stabilized in recent decades after years of increase. Denmark’s robust registry data and universal healthcare system offer a unique opportunity for reliable epidemiological analysis. Our results establish a benchmark for future demographic studies in the field of multiple sclerosis.

中文翻译：

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丹麦多发性硬化症（1950-2023 年）：平均年龄、性别分布、发病率和患病率


随着预期寿命的延长和疾病管理的进步，我们预计多发性硬化症人群正在老龄化。然而，支持这一假设的证据仍然很少。我们的研究旨在确定丹麦多发性硬化症人群的平均年龄是否增加，并分析性别分布、发病率和患病率的变化，所有这些都会影响年龄构成。我们通过将丹麦多发性硬化症登记处的全国数据与人口统计登记处、丹麦死因登记处和历史移民登记处联系起来，进行了一项队列研究。我们纳入了 1950 年至 2023 年每年 1 月 1 日居住在丹麦的所有确诊为多发性硬化症的活着患者。我们计算了 1950 年至 2023 年每年丹麦多发性硬化症人群的平均和中位年龄、年龄分布、性别分布、发病率和患病率。我们纳入了 28 145 例多发性硬化症患者。丹麦多发性硬化症人群的平均年龄在 1970 年代后期一直增加到 ∼52.5 岁，直到 1990 年才稳定下来。平均年龄在 2005 年略有下降至 51.2 岁，随后在 2023 年上升至 54.2 岁的峰值。1975 年，女性占多发性硬化症人群的 58.7%，到 2000 年增加到 65.7%，到 2023 年增加到 68.5%。直到 1975 年，多发性硬化症的发病率一直稳定在每 100 000 人中约 3.5 人，并在 2000 年稳步增加三倍多，达到每 100 000 人中 11.4 人。尽管存在波动，但从 2000 年到 2022 年保持相对稳定，与前二十年相比，2022 年略有下降。总体患病率和性别特异性患病率均呈上升趋势，尤其是在女性中。 我们的研究表明，丹麦多发性硬化症人群的平均年龄有所增加，尽管没有预期的那么决定性。女性比例与患病率同步增长，而发病率在经过多年的增加后，近几十年似乎已经趋于稳定。丹麦强大的登记数据和全民医疗保健系统为可靠的流行病学分析提供了独特的机会。我们的结果为多发性硬化症领域未来的人口学研究建立了基准。