Objective: Multiple sclerosis (MS) is associated with substantial morbidity. The impact of comorbidity on MS is unknown, but comorbidity may explain some of the unpredictable progression. Comorbidity is common in the general population, and is associated with adverse health outcomes. To begin understanding the impact of comorbidity on MS, we need to know the breadth, type, and frequencies of comorbidities among MS patients. Using the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry, we aimed to describe comorbidities and their demographic predictors in MS.
Methods: In October 2006, we queried NARCOMS participants regarding physical comorbidities. Of 16,141 participants meeting the inclusion criteria, 8983 (55.7%) responded.
Results: Comorbidity was relatively common; if we considered conditions which are very likely to be accurately self-reported, then 3280 (36.7%) reported at least one physical comorbidity. The most frequently reported comorbidities were hypercholesterolemia (37%), hypertension (30%), and arthritis (16%). Associated with the risk of comorbidity were being male [females vs. males, odds ratio (OR) 0.77; 0.69-0.87]; age (age >60 years vs. age < or = 44 years, OR 5.91; 4.95-7.06); race (African Americans vs. Whites, OR 1.46; 1.06-2.03); and socioeconomic status (Income <$15,000 vs. Income >$100,000, OR 1.37; 1.10-1.70).
Conclusions: Comorbidity is common in MS and similarly associated with socioeconomic status.