Supplementary Material for: Comorbidities Are Associated with Altered Health Services Use in Multiple Sclerosis: A Prospective Cohort Study

Background: Persons with multiple sclerosis (MS) use health resources with greater frequency than the general population. However, little is known regarding which patient characteristics might contribute. Objective: The study aimed to evaluate characteristics associated with healthcare use in MS patients. Methods: Consecutive MS clinic attendees were recruited (September–November 2010), with clinical, demographic, and patient-completed questionnaires collected at 3 visits over 2 years. Linkage with administrative data (hospital, physician, and pharmacy records) provided healthcare use outcomes until December 31, 2013. Findings were reported as adjusted rate ratios (adjRRs) using negative binomial regression. Results: A total of 340 MS patients with a mean (SD) age of 48.4 (12.0) years and subsequent follow-up of 3.1 (0.34) years were included. Fatigue and high physical comorbidity count (≥3 vs. none) were significantly associated with higher rates of physician encounters (adjRRs: 1.37 and 1.52, respectively), prescriptions filled (adjRRs: 1.25 and 1.40), and hospitalizations (adjRRs: 4.02 and 3.45). In addition, anxiety, disruptive pain, and perceived functional cognitive difficulties were associated with higher rates of physician encounters and prescriptions dispensed (adjRR ranged from 1.28 to 1.48). Discussion: The presence of fatigue and higher physical comorbidity burden were associated with higher rates of health services use. Findings have implications for those examining healthcare burden or organizing health services for persons with MS.