Purpose of the work: to obtain reliable connections between the nature of the prognosis, the ways of the formation of stages of progression (SP) and the variants of progression in progredient types (PT) of multiple sclerosis (MS) using mathematical analysis.

A permutation test was used to perform a correlation analysis of the links between clinical indicators characterizing the stages in PT MS: the onset stage, the recurrent stage (RS) in the secondary progressive course (SPC), and the progression stage. The reliability of the relationships between the nature of the prognosis, the pathways and variants of progression, the duration of the RS in SPMS and the stage of stabilization (STB) in the primary progressive type of multiple sclerosis (PPMS) was studied using 2 × 2 contingency tables. The strength of the bond was measured by the positive and negative values of the Yule correlation coefficient.

In SPMS, for the 1st pathway of the formation of the stage of secondary progression (presence of RS after the debut), an uncertain prognosis prevailed, which was associated with prolonged remission after the debut and a progressive variant of progression. For the 2nd path (no SP after the debut), a short remission after the debut and a recurrent variant of progression were significantly more frequent with a poor prognosis. A statistically significant strong association was found between poor prognosis and steady progression. There were no significant associations between prognosis, pathways and variants of progression.

In PPMS for the 1st pathway of the formation of the stage of primary progression (the presence of the STB stage after the debut), an uncertain prognosis prevailed with a gradual rate of development of a long onset and a recurrent variant of progression. For the 2nd path (the absence of the STB stage after the debut), an unfavorable prognosis was more common with a slowed rate of development of the debut, dysfunction of the pelvic organs in the debut, and a steady progression. The steady variant of progression was closely associated with an unfavorable prognosis, which significantly more often occurred in the absence of the STB stage after the debut, and the progressive variant was statistically significant for an uncertain prognosis with the average duration of the STB stage after the debut.