Diagnostic Delay of Multiple Sclerosis in a Portuguese Population

Introduction: Multiple sclerosis is a chronic inflammatory disease, in which a diagnostic delay could reduce the available therapeutic options. Therefore, it is important to monitor the time to diagnosis and understand factors that may potentially reduce it. The objective of this study was to determine the time between the first symptoms and the diagnosis of multiple sclerosis and which factors may contribute to a diagnostic delay. Material and Methods: Cross-sectional multicenter study, with retrospective data analysis, conducted in five tertiary Portuguese hospitals. Patients were consecutively selected from each local multiple sclerosis patients' database. Sociodemographic and initial clinical data were collected through a questionnaire. Date of final diagnosis and multiple sclerosis classification was obtained from clinical files. Results: A total of 285 patients were included with mean age at diagnosis of 36 years. The median time between first clinical manifestation and multiple sclerosis diagnosis was nine months (IQR 2 - 38). Diagnostic delay was associated with an older age (p < 0.001; r = 0.35), motor deficit at onset [26.5 months (IQR 4.5 - 56.5); p = 0.0005], higher number of relapses before diagnosis (p < 0.001; r= 0,626), first observation by other medical specialty [11 months (IQR 2 - 48); p < 0.001], prior alternative diagnosis [20 months (IQR 4 - 67.5); p < 0.001] and primary progressive subtype [37 months (IQR 25 - 64.5); p < 0.001]. The most significant delay occurred between the initial symptom and neurological observation. Discussion: A significant delay occurred between initial symptoms and the diagnosis of multiple sclerosis, reflecting the need to increase awareness of this entity and its diverse symptom presentation.