Background: The frequency of paediatric-onset multiple sclerosis (POMS) and the precise risk of secondary progression of disease are largely unknown in the Middle East. This cross-sectional cohort study assessed the risk and examined prognostic factors for time to onset of secondary progressive multiple sclerosis (SPMS) in a cohort of POMS patients. Methods: The Kuwait National MS Registry database was used to identify a cohort of POMS cases (diagnosed at age <18 years) from 1994 to 2013. Data were abstracted from patients’ records. A Cox proportional hazards model was used to evaluate the prognostic significance of the variables considered. Results: Of 808 multiple sclerosis (MS) patients, 127 (15.7%) were POMS cases. The median age (years) at disease onset was 16.0 (range 6.5–17.9). Of 127 POMS cases, 20 (15.8%) developed SPMS. A multivariable Cox proportional hazards model showed that at MS onset, brainstem involvement (adjusted hazard ratio 5.71; 95% confidence interval 1.53–21.30; P=0.010), and POMS patient age at MS onset (adjusted hazard ratio 1.38; 95% confidence interval 1.01–1.88; P=0.042) were significantly associated with the increased risk of a secondary progressive disease course. Conclusions: This study showed that POMS patients with brainstem/cerebellar presentation and a relatively higher age at MS onset had disposition for SPMS and warrant an aggressive therapeutic approach.
Bayesian Estimation in the Proportional Hazards Model of Random Censorship under Asymmetric Loss Functions
