Ruth-Ann Marrie

Vascular comorbidity is associated with more rapid disability progression in multiple sclerosis

Background: Vascular comorbidity adversely influences health outcomes in several chronic conditions. Vascular comorbidities are common in multiple sclerosis (MS), but their impact on disease severity is unknown. Vascular comorbidities may contribute to the poorly understood heterogeneity in MS disease severity. Treatment of vascular comorbidities may represent an avenue for treating MS. Methods: A total of 8,983 patients with MS enrolled in the North American Research Committee on Multiple Sclerosis Registry participated in this cohort study. Time from symptom onset or diagnosis until ambulatory disability was compared for patients with or without vascular comorbidities to determine their impact on MS severity. Multivariable proportional hazards models were adjusted for sex, race, age at symptom onset, year of symptom onset, socioeconomic status, and region of residence. Results: Participants reporting one or more vascular comorbidities at diagnosis had an increased risk of ambulatory disability, and risk increased with the number of vascular conditions reported (hazard ratio [HR]/condition for early gait disability 1.51; 95% confidence interval [CI] 1.41–1.61). Vascular comorbidity at any time during the disease course also increased the risk of ambulatory disability (adjusted HR for unilateral walking assistance 1.54; 95% CI 1.44–1.65). The median time between diagnosis and need for ambulatory assistance was 18.8 years in patients without and 12.8 years in patients with vascular comorbidities. Conclusions: Vascular comorbidity, whether present at symptom onset, diagnosis, or later in the disease course, is associated with a substantially increased risk of disability progression in multiple sclerosis. The impact of treating vascular comorbidities on disease progression deserves investigation.

The rising prevalence and changing age distribution of multiple sclerosis in Manitoba

Objective: Several studies suggest an increasing prevalence of multiple sclerosis (MS) in Canada. We aimed to validate a case definition for MS using administrative health insurance data, and to describe the incidence and prevalence of MS in Manitoba, Canada. Methods: We used provincial administrative claims data to identify persons with demyelinating disease using International Classification of Diseases 9/10 codes and prescription claims. To validate the case definition, questionnaires were mailed to 2,000 randomly selected persons with an encounter for demyelinating disease, requesting permission for medical records review. We used diagnoses abstracted from medical records as the gold standard to evaluate candidate case definitions using administrative data. Results: From 1984 to 1997, cases of MS using claims data were defined as persons with ≥7 medical contacts for MS. From 1998 onward, cases were defined as persons with ≥3 medical contacts. As compared to medical records, this definition had a positive predictive value of 80.5% and negative predictive value of 75.5%. From 1998 to 2006, the average age- and sex-adjusted annual incidence of MS per 100,000 population was 11.4 (95% confidence interval [CI] 10.7–12.0). The age-adjusted prevalence of MS per 100,000 population increased from 32.6 (95% CI 29.4–35.8) in 1984 to 226.7 (95% CI 218.1–235.3) in 2006, with the peak prevalence shifting to older age groups. Conclusion: The prevalence of multiple sclerosis (MS) in Manitoba is among the highest in the world. The rising prevalence with minimally changing incidence suggests improving survival. This study supports the use of administrative data to develop case definitions and further define the epidemiology of MS.

Comorbidity delays diagnosis and increases disability at diagnosis in MS

Background: Comorbidity is common in the general population and is associated with adverse health outcomes. In multiple sclerosis (MS), it is unknown whether preexisting comorbidity affects the delay between initial symptom onset and diagnosis (“diagnostic delay”) or the severity of disability at MS diagnosis. Objectives: Using the North American Research Committee on Multiple Sclerosis Registry, we assessed the association between comorbidity and both the diagnostic delay and severity of disability at diagnosis. In 2006, we queried participants regarding physical and mental comorbidities, including date of diagnosis, smoking status, current height, and past and present weight. Using multivariate Cox regression, we compared the diagnostic delay between participants with and without comorbidity at diagnosis. We classified participants enrolled within 2 years of diagnosis (n = 2,375) as having mild, moderate, or severe disability using Patient Determined Disease Steps, and assessed the association of disability with comorbidity using polytomous logistic regression. Results: The study included 8,983 participants. After multivariable adjustment for demographic and clinical characteristics, the diagnostic delay increased if obesity, smoking, or physical or mental comorbidities were present. Among participants enrolled within 2 years of diagnosis, the adjusted odds of moderate as compared to mild disability at diagnosis increased in participants with vascular comorbidity (odds ratio [OR] 1.51, 95% CI 1.12–2.05) or obesity (OR 1.38, 95% CI 1.02–1.87). The odds of severe as compared with mild disability increased with musculoskeletal (OR 1.81, 95% CI 1.25–2.63) or mental (OR 1.62, 95% CI 1.23–2.14) comorbidity. Conclusions: Both diagnostic delay and disability at diagnosis are influenced by comorbidity. The mechanisms underlying these associations deserve further investigation.

Comorbidity, socioeconomic status and multiple sclerosis

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 ≤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 <

The burden of mental comorbidity in multiple sclerosis: frequent, underdiagnosed, and undertreated

15,000 vs. Income >

Does multiple sclerosis–associated disability differ between races?

100,000, OR 1.37; 1.10–1.70). Conclusions Comorbidity is common in MS and similarly associated with socioeconomic status.

High frequency of adverse health behaviors in multiple sclerosis

Background Mental comorbidity is common in multiple sclerosis (MS), but some studies suggest that mental comorbidity may be underrecognized and undertreated. Objective Using the North American Research Committee on MS Registry, we assessed the frequency of mental comorbidities in MS and sociodemographic characteristics associated with diagnosis and treatment of depression. Methods We queried participants regarding depression, anxiety, bipolar disorder, and schizophrenia. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CESD); a score ≥21 indicated probable major depression. Results Mental comorbidity affected 4264 (48%) responders; depression most frequently (4012, 46%). Among participants not reporting mental comorbidity, 751 (16.2%) had CESD scores ≥21 suggesting undiagnosed depression. Lower socioeconomic status was associated with increased odds of depression (Income

Changes in the ascertainment of multiple sclerosis

15,000–30,000 vs >

Impact of loss of mobility on instrumental activities of daily living and socioeconomic status in patients with MS

100,000 OR 1.34; 1.11–1.62), undiagnosed depression (Income

Disparities in the management of multiple sclerosis–related bladder symptoms

15,000–30,000 vs >