Beslay Marie, Beau Anna-Belle, Messina Davide, Benevent Justine, Ballardini Elisa, Barrachina-Bonet Laia, Cavero-Carbonell Clara, Coldea Alex, García-Villodre Laura, Geldhof Anja, Gini Rosa, Hellwig Kerstin, Jordan Sue, Leinonen Maarit K, Lopez-Leon Sandra, Manfrini Marco, Martikainen Visa, Mitter Vera R, Neville Amanda J, Nordeng Hedvig, Puccini Aurora, Vukusic Sandra, Damase-Michel Christine, Geissbühler Yvonne, Morris Joan K
CERPOP-SPHERE Team, Toulouse University Hospital, Inserm UMR 1295, Toulouse University, Toulouse, France.
ARS Toscana, Florence, Italy.
Eur J Epidemiol. 2025 Jul 31. doi: 10.1007/s10654-025-01243-8.
Multiple sclerosis (MS) is a chronic autoimmune condition primarily affecting women and often diagnosed during childbearing years. This study assessed the impact of the lookback period and calculation method on MS prevalence in three healthcare data sources including women of childbearing age (from Italy, Norway and Wales) and three data sources including pregnant women (from France, Finland and Spain). Women aged 15 to 49 years from 2005 to 2019 were included, data from pregnant women were collected around the pregnancy period. MS cases were identified based on at least one MS diagnosis or one dispensation for an MS-specific medication. All data sources provided inpatient diagnoses and medication data; outpatient diagnoses were available in Norway and Finland, and primary care diagnoses in Norway, Finland and Wales. We assessed MS case detection rate by lookback period, and compared three methods for estimating yearly MS prevalence: period prevalence (PP), average point prevalence (APP) and person-time prevalence (PTP). The estimated lookback periods to identify 95% of MS cases ranged from 6 to 9 years. APP and PTP provided lower prevalence estimates than PP, especially when the lookback to identify MS was short. In women of childbearing age, MS prevalence increased over time with all calculation methods and the highest MS prevalence was observed in Norway (PP of 402 per 100,000 in 2019). Finland showed the highest MS prevalence in pregnant women (PP of 218 per 100,000 in 2018). This study highlights the importance of sufficient lookback and available data to accurately estimate MS prevalence.
多发性硬化症（MS）是一种慢性自身免疫性疾病，主要影响女性，且常在育龄期被诊断出来。本研究评估了回顾期和计算方法对三个医疗保健数据源中MS患病率的影响，这三个数据源包括育龄女性（来自意大利、挪威和威尔士），以及另外三个包括孕妇的数据源（来自法国、芬兰和西班牙）。纳入了2005年至2019年15至49岁的女性，孕妇的数据在孕期前后收集。MS病例是根据至少一次MS诊断或一次MS特异性药物配药来确定的。所有数据源都提供了住院诊断和用药数据；挪威和芬兰有门诊诊断数据，挪威、芬兰和威尔士有初级保健诊断数据。我们按回顾期评估了MS病例检出率，并比较了三种估计年度MS患病率的方法：期间患病率（PP）、平均时点患病率（APP）和人时患病率（PTP）。识别95%的MS病例所需的估计回顾期为6至9年。APP和PTP提供了比PP更低的患病率估计值，尤其是在识别MS的回顾期较短时。在育龄女性中，所有计算方法得出的MS患病率均随时间增加，且挪威的MS患病率最高（2019年PP为每10万人402例）。芬兰孕妇的MS患病率最高（2018年PP为每10万人218例）。本研究强调了足够的回顾期和可用数据对于准确估计MS患病率的重要性。
