Misdiagnosis and underdiagnosis of multiple sclerosis: A systematic review and meta-analysis

Background: Diagnostic errors in multiple sclerosis (MS) impact patients and healthcare systems. Objectives: This study aimed to determine the prevalence of MS misdiagnosis and underdiagnosis, time delay in reaching a correct diagnosis and potential impact of sex. Methods: Systematic review and meta-analysis on MS diagnostic errors. Results: Out of 3910 studies, we included 62 for a qualitative synthesis and 24 for meta-analyses. Frequency of misdiagnosis (incorrect assignment of an MS diagnosis) ranged from 5% to 41%, with a pooled proportion based on six studies of 15% (95% CI: 9%–26%, n = 1621). The delay to rectify a misdiagnosis ranged from 0.3 to 15.9 years. Conversely, underdiagnosis (unrecognized diagnosis of MS) ranged from 3% to 58%, with a pooled proportion in four studies of 36% (95% CI: 20%–55%, n = 728). Pooling seven studies comprising 2851 individuals suggested a diagnostic delay to establish a correct MS diagnosis of 17.3 months (95% CI: 11.9–22.7) in patients underdiagnosed. In a meta-analysis of five studies, women were 2.1 times more likely to be misdiagnosed with MS compared to men (odds ratio, 95% CI: 1.53–2.86). Conclusion: This study provides summary-level evidence for the high prevalence of MS misdiagnosis and underdiagnosis. Future studies are needed to understand the causes of these diagnostic challenges in MS care.