We achieved a significant milestone in 2023 by publishing the Multiple Sclerosis Data Alliance (MSDA) core dataset (CDS). The scientific paper featuring the CDS can be accessed here, and the data dictionary can also be found on the MS Data Alliance website. This consensus on the CDS is a major advance for all stakeholders within the MS community, as it provides direction for new and emerging registries in defining their datasets and accelerates harmonisation across registries and initiatives.

To gain a deeper understanding of MS and the unique patterns of disease progression and treatment response in each individual, a substantial amount of data is required. In an ideal scenario, the data in question should be real-world data (RWD) obtained from routine treatment and care provided to persons with MS. This type of data is distinct from information gathered in a controlled environment, such as a clinical trial, as it pertains to a patient's health status and care experiences in everyday life.

Sharing real-world data (RWD) globally can help address common MS challenges more quickly. However, it is crucial to determine which variables and in what format should be collected early on. This is where the MS Data Alliance CDS plays a significant role. The CDS aims to minimise the differences between various real-world MS data sources. The MS Data Alliance Core Dataset is defined as a set of variables that serve as common ground between different areas of interest in MS and their associated minimal datasets. The CDS adopts a comprehensive strategy that extends beyond a particular research inquiry or MS domain, such as pharmacovigilance.

The CDS was developed within a specified timeframe, with a focus on incorporating clinical MS variables that are commonly observed in real-world datasets and can be easily obtained to enable high coverage of data.

A total of 44 variables, categorised into eight groups, were developed through the coordination of a multi-stakeholder task force comprising 20 experts in MS and RWD. This group of experts consisted of clinicians, data managers, MS registry and cohort leaders, a patient organisation, pharmaceutical industry representatives, and regulators and convened on multiple occasions to define the CDS. The different stakeholders provided a rich diversity of opinions and experiences that contributed to in-depth discussions on the key variables in MS. The experts, with representatives from North and South America, Northeast Africa, Europe, and Oceania, were already involved in the MS Data Alliance activities. The process of designing, discussing, assessing, and coming to a consensus for the CDS was orchestrated and coordinated by the MS Data Alliance, with Tina Parciak as the leader and Liesbet Peeters as the chair.