System-Level Variation in Multiple Sclerosis Care Outcomes: Initial Findings from the Multiple Sclerosis Continuous Quality Improvement Research Collaborative

Multiple sclerosis (MS) is a "3C" (complex, chronic, costly) condition that is a common and disabling neurological illness affecting approximately 1 million adults in the United States. MS has been studied at the basic science, individual, and population levels, but not at the system level to assess small-area variation effects on MS population health outcomes. System-level effects have been observed in other 3C conditions including cystic fibrosis, rheumatoid arthritis, and inflammatory bowel disease. The authors report here on system-level variation findings from the baseline period during the first year of the Multiple Sclerosis Continuous Quality Improvement (MS-CQI) study. Stepwise binary logistic regression analyses were conducted to investigate system-level (small-area variation) effects on MS relapses (exacerbations), disease-modifying therapy (DMT) utilization, and brain MRI utilization, controlling for demographics (age and sex) and other potential confounders. Significant differences were observed in people with MS (PwMS) between centers for a number of demographic and disease characteristics, including sex, age, and MS subtype. Controlling for these factors, significant system-level effects were observed on outcomes, including DMT utilization, MRI utilization, and relapses. Significant relationships also were observed between outcomes and urgent care utilization, including emergency department visits and hospitalizations. This initial study provides evidence establishing the presence of system-level variation effects on MS outcomes in a multicenter population study - where PwMS get their care can influence their outcomes. Results support continued systems-level research and improvement initiatives to optimize MS population health outcomes in this challenging and costly complex chronic condition.