A method for evaluating treatment switching criteria in multiple sclerosis
Authors investigated a method to evaluate a treatment switching approach, namely treatment change after one multiple sclerosis (MS) relapse. Healy BC, Glanz BI, Stankiewicz J, Buckle G, Weiner H, Chitnis T., Mult Scler. 2010 Aug 24.
Patients who experienced a relapse while on a first-line disease-modifying therapy, glatiramer acetate, were identified. Based on their subsequent course, patients were divided into two groups: those who changed treatment and those who did not. Patients were allowed to change to any other treatment.
Subsequent annualized relapse rate and time to next relapse were compared in the two groups. Statistical modeling showed that there was no significant difference between groups in terms of relapse rate (rate ratio; 95% CI = 0.68; 0.35, 1.31) and time to next relapse (hazard ratio; 95% CI = 0.61; 0.30, 1.25). All secondary analyses confirmed these results. In addition, no significant difference in time to sustained progression on the Expanded Disability Status Scale(EDSS) was observed (p > 0.05).Authors conclude that a single relapse may not be sufficient to
indicate treatment failure, and add that although clinical
confounders were addressed in study modeling, unmeasured
confounders, particularly the presence of magnetic resonance
imaging activity, may have biased the conclusion.