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. 2021 Oct;27(12):1902-1913.
doi: 10.1177/13524585211031791. Epub 2021 Jul 30.

High prevalence of comorbidities at diagnosis in immigrants with multiple sclerosis

Dalia Rotstein  1 , Colleen Maxwell  2 , Karen Tu  3 , Jodi Gatley  4 , Priscila Pequeno  4 , Alexander Kopp  4 , Ruth Ann Marrie  5
Affiliations

High prevalence of comorbidities at diagnosis in immigrants with multiple sclerosis

Dalia Rotstein et al. Mult Scler. 2021 Oct.

Abstract

Background: Multiple sclerosis (MS) has been associated with certain comorbidities in general population studies, but it is unknown how comorbidity may affect immigrants with MS.

Objective: To compare prevalence of comorbidities in immigrants and long-term residents at MS diagnosis, and in matched control populations without MS.

Methods: We identified incident MS cases using a validated definition applied to health administrative data in Ontario, Canada, from 1994 to 2017, and categorized them as immigrants or long-term residents. Immigrants and long-term residents without MS (controls) were matched to MS cases 3:1 on sex, age, and geography.

Results: There were 1534 immigrants and 23,731 long-term residents with MS matched with 4585 and 71,193 controls, respectively. Chronic obstructive pulmonary disease (COPD), diabetes, hypertension, ischemic heart disease, migraine, epilepsy, mood/anxiety disorders, schizophrenia, inflammatory bowel disease (IBD), and rheumatoid arthritis were significantly more prevalent among immigrants with MS compared to their controls. Prevalence of these conditions was generally similar comparing immigrants to long-term residents with MS, although COPD, epilepsy, IBD, and mood/anxiety disorders were less prevalent in immigrants.

Conclusion: Immigrants have a high prevalence of multiple comorbidities at MS diagnosis despite the "healthy immigrant effect." Clinicians should pay close attention to identification and management of comorbidity in immigrants with MS.

Keywords: Multiple sclerosis; comorbidity; immigrants; prevalence.

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Conflict of interest statement

Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Dalia Rotstein has received research support from the Consortium of Multiple Sclerosis Centers (CMSC), the Multiple Sclerosis Society of Canada, and Roche. She has served as a speaker or consultant for Alexion, Biogen, EMD Serono, Novartis, Roche, and Sanofi Aventis. Colleen Maxwell has received research funding from the Canadian Institutes of Health Research, P.S.I. Foundation, MS Society of Canada, Consortium of MS Centers, MS Scientific Research Foundation, Ontario Ministry of Health and Long-Term Care-Health System Research Fund, Canadian Frailty Network, Partners for Canadian Consortium on Neurodegeneration in Aging, Network for Aging Research-University of Waterloo. She is supported by a University Research Chair at the University of Waterloo. Karen Tu has received research funding from the Department of Defense United States of America, MaRS Innovation Fund, Canadian Institutes of Health Research (CIHR), Rathlyn Foundation, Canadian Dermatology Foundation, Canadian Rheumatology Association (CRA), Canadian Initiative for Outcomes in Rheumatology Care (CIORA), Toronto Rehab Institute Chair Fund, University of Toronto Practice-Based Research Network (UTOPIAN), PSI Foundation, Cancer Care Ontario (CCO) Clinical Programs & Quality Initiatives, Arthritis Society, McLaughlin Centre Accelerator Grant, MS Society of Canada and Consortium of MS Centers, Ontario SPOR Support Unit, Ontario Institute for Cancer Research (OICR) Health Services Research Program, Vascular Network, COVID-19 Pandemic Response and Impact Grant Program (Co-RIG), and Heart and Stroke Foundation of Ontario. She also receives a research scholar award from the Department of Family and Community Medicine at the University of Toronto. Ruth Ann Marrie receives research funding from CIHR, Research Manitoba, Multiple Sclerosis Society of Canada, Multiple Sclerosis Scientific Foundation, Crohn’s and Colitis Canada, National Multiple Sclerosis Society, CMSC and the US Department of Defense. She is supported by the Waugh Family Chair in Multiple Sclerosis. Jodi Gatley, Priscila Pequeno, and Alexander Kopp have nothing to disclose.

Figures

Figure 1.
Figure 1.
Cohort selection flowchart. The flowchart demonstrates how the study cohort was selected.
Figure 2.
Figure 2.
Prevalence ratios of individual comorbidities in MS cases versus matched controls by immigrant status and gender. This figure shows prevalence ratios for specific conditions in MS cases versus matched controls. For each condition, prevalence ratios are displayed for four different groups: immigrant women, long-term resident (LTR) women, immigrant men, and LTR men. For example, prevalence ratio for COPD immigrant women represents prevalence of COPD in immigrant women with MS divided by prevalence of COPD in immigrant women controls. Certain conditions (e.g. epilepsy, IBD, RA, schizophrenia) were omitted due to small absolute numbers of cases in the female and/or male immigrant cohorts and the resultant risk of loss of confidentiality. COPD: chronic obstructive pulmonary disease; HTN: hypertension; IHD: ischemic heart disease.
See this image and copyright information in PMC

Comment in

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