Study Compares 2024 vs 2017 McDonald Diagnostic Criteria in Real World Population

Study results presented at the 41st Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) demonstrate that the 2024 revisions to the McDonald criteria improve both sensitivity and speed of multiple sclerosis (MS) diagnosis compared with the 2017 McDonald criteria. 

The study included 326 individuals with suspected MS who presented to the MS Centre of Catalunya between January 2022 and March 2025. Participants were eligible if they had incidental MRI findings suggestive of demyelinating disease, an attack with characteristic symptoms and signs of MS, or evidence of objective progression. The completion of the diagnostic workup was used as the baseline. Researchers collected clinical and imaging data, including MRI and optical coherence tomography findings, visual evoked potentials, and oligoclonal bands. The 2017 and 2024 frameworks were evaluated using McNemar’s test for yield, a Cox model for paired data for time to diagnosis, and Cohen’s kappa for agreement.

Key findings include:

• More individuals were diagnosed using the 2024 McDonald criteria compared with the 2017 criteria at baseline (71% vs 47%, P<0.001) and follow-up (83% vs 60%, P<0.001).
• Compared with the 2017 criteria, individuals who met the 2024 McDonald criteria had a 43% higher probability of diagnosis and were diagnosed earlier (hazard ratio [HR] 1.43; 95%CI, 1.17 to 1.74; P<0.001).
• Compared with the 2017 criteria, the 2024 McDonald criteria revisions demonstrated high agreement (κ=0.76; z=14.2; P<0.001) and greater sensitivity.
• All individuals who met the 2017 diagnostic criteria also met the 2024 diagnostic criteria.