Relapsing-remitting multiple sclerosis (RRMS) is a chronic disease affecting about 400 000 people in the US characterized by increasing patient disability and burden on society. While there is no cure for multiple sclerosis (MS), pharmaceutical treatments exist that can limit the number of relapses a patient experiences, and slow disease progression. One such class of agents used to treat RRMS are the interferons: interferon-beta-1a (Rebif and Avonex and interferon-beta-1b (Betaseron and Extavia). Patients must take these injectable medications regularly to achieve the optimal outcomes. However, patient issues and potential adverse effects of the medication may prevent the patient from taking the medication as directed and lower adherence. To date, limited evidence exists regarding the effect of patient adherence to interferon-beta therapies on clinical and economic outcomes.
The purpose of this study was to explore the impact of patient adherence to interferon-beta therapy on MS relapse rates and healthcare resource utilization.
Using a non-experimental, retrospective cohort design, a sample population (n = 1606) was drawn from patients identified in a database that includes both pharmacy and medical claims data. The study population was separated into two groups based on a measure of medication possession ratio (MPR)-adherent and non-adherent patients, and adherence was defined as MPR > or =85% in a given year during the study period (2006-8). Key outcome variables included MS relapses and healthcare resource utilization. Data were analysed using parametric and non-parametric statistics, and regression modeling.
During the study period, the average MPR for all patients on interferon-beta therapy varied from 72% to 76%. Only 27-41% of patients in each year were considered adherent (i.e. MPR > or =85%) and only 4% of patients had an MPR of > or =85% throughout the 3-year study period (2006-8). Patients who were adherent tended to have a lower risk of relapses over 3 years than non-adherent patients. A significantly lower risk of relapses was found in 2006 (risk ratio [RR] 0.89; 95% CI 0.81, 0.97). Furthermore, an increasingly larger effect emerged between adherence and relapses when comparing adherent patients (MPR > or =85%) with subgroups of non-adherent patients (
Our paper analyzes technical efficiency in the production of aggregate health outcomes of reduced infant mortality and increased life expectancy, using Organization for Economic Cooperation and Development (OECD) health data. Application of data envelopment analysis (DEA) reveals that some countries achieve relative efficiency advantages, including those with good health outcomes (Japan, Sweden, Norway, and Canada) and those with modest health outcomes (Mexico and Turkey). We conclude the USA may learn from countries more economical in their allocation of healthcare resources that more is not necessarily better. Specifically, we find that the USA can substantially reduce inputs while maintaining the current level of life expectancy.