Long-term MS secondary progression: Derivation and validation of a clinical risk score.

Objective: The risk of progression of multiple sclerosis (MS) related to the association of prognostic factors present at disease onset has rarely been explored. We aimed to construct a clinical risk score for MS long-term progression that could be easily applied in clinical practice.

Patients And Methods: Among 432 patients with MS, 288 patients were selected as a derivation sample for identification of the knowledge prognostic factors more associated with long-term progression. One point was given to each risk factor identified as statistically significant by the adjusted model, and the sum of the points gave the overall risk score. Subsequently the score was applied to the remaining 144 patients to confirm if those with higher scores had reached MS secondary progression.

Results: The prognostic factors identified as independently associated with long-term progression were: no specific MS treatment before EDSS 3, age of onset older than 30 years, pyramidal and cerebellar impairment as the first manifestation of disease, time interval between the first and second relapses less than 2 years, and African ancestry. There was no significant difference between expected and observed number of patients in progression (44 vs. 31, p = 0.966), indicating that the score was able to predict the progression in the validation sample. There was no significant difference between patients with low risk (≤ 2 points) (p = 0.98) and high risk (≥ 3 points) (p = 0.48) in the derivation versus validation samples. In the derivation sample, the patients with three or more points had a 2.8-fold increased risk of progression [hazard ratio (HR): 2.8; 95 % confidence interval (CI): 1.2-6.3; p = 0.014).

Conclusion: The score proposed was capable of predicting long-term MS progression.