Effet des médicaments immunomodulateurs sur la progression de la sclérose en plaques et l’utilisation des soins
Background: Multiple sclerosis (MS) is a chronic disease that can impact on the quality of life of patients in multiple ways. Objectives: The main goal of this thesis is the modelling of the temporal aspects of MS and its treatment. The specific goals of the thesis are: 1) To estimate the long-term effect of immunomodulatory drugs on the progression and the disease activity of MS; 2) To describe, at the population level, the evolution of health services related to MS and to estimate the effect of age at diagnosis on the use of health services for MS; 3) To assess the propensity of group-based trajectory modelling to detect the number of trajectories, the shape of trajectories and the number of subjects in each group of trajectories; 4) To propose a new graphical representation to visualize longitudinal patterns of medication dose and apply it to an immunomodulator used for treating MS patients. Methods: The analysis of objectives 1 and 4 were carried out using data from patients with a diagnosis of MS treated at the Montreal MS clinic, CHUM. The study was based on information collected during the clinical follow-up of patients between September 1975 and December 2016. The socio-demographic characteristics, reproductive history in women, disease progression, comorbidities and medications were collected at each medical visit. For objective 2, the Québec Birth Cohort on Immunity and Health was used. The individuals in this cohort were born between 1970 and 1974 and follow-up was carried out until 2014 using administrative health and demographic databases. Socio-demographic variables and information regarding the use of health services for MS were obtained for everyone. For objective 3, data were generated based on scenario from the literature. The analyses carried out include the use of marginal structural models (objective 1), generalized additive models (objective 2) and group-based trajectory methods (objectives 3 and 4). Results: The results showed that the use of interferon-beta and glatiramer acetate is associated with a decrease in the rate of progression of disability and relapses. We also found some differences in neurologist and general practitioner visit rates between people diagnosed with MS before age 29 and those diagnosed later. In addition, we have shown the importance of using several statistical criteria in order to assess the adequacy of groups of trajectories. Conclusions:  The use of several variables for the outcomes in the first two objectives gave us a holistic view of the treatment, care and progression of MS. This thesis also makes recommendations for the good use of the trajectory modelling and proposes a graphic alternative to visualize patterns of medication dose.
Québec Multiple sclerosis Interferon-beta Glatiramer acetate Progression of MS Health services