Epidemiology and impact of myalgic encephalomyelitis and chronic fatigue syndrome (ME/CFS) in Canada: A multi-centre population-based study

Myalgic encephalomyelitis (also known as chronic fatigue syndrome or ME/CFS) is a disabling illness. The causes of ME/CFS are not well understood. Getting a diagnosis can be challenging, and there are limited effective treatments. Patients report barriers to care and many unmet health needs. The true burden of ME/CFS is unknown but has increased since the COVID-19 pandemic. This is because some people develop persistent symptoms after COVID-19 infection (also known as Long COVID). Some Long COVID cases are indistinguishable from ME/CFS. Data on ME/CFS in Canada are scarce. Without this data, issues for people with ME/CFS persist. This project will accelerate the collection and understanding of data on ME/CFS. The goal is to characterize the ME/CFS population and evaluate their unmet needs. Our analysis includes people with ME/CFS due to Long COVID. First, we will produce an accurate database of people with ME/CFS using multiple methods. Second, we will estimate the number of people living with ME/CFS in Canada. Third, we will compare ME/CFS "cases" with controls. Fourth, we will investigate healthcare needs, inequities, and access to care for people with ME/CFS. We will use a national database called CanPath to access data from 3 provinces: British Columbia, Ontario, and Quebec. We will use standardized questionnaires to confirm the diagnosis of ME/CFS. We will compare disease severity and quality of life between ME/CFS cases and controls. We will also compare pre-pandemic ME/CFS cases with COVID-19-related cases of ME/CFS. We will also describe the journey people take to find health care and public services. The project includes people with lived experience of ME/CFS and Long COVID. The findings will provide a better understanding of the severity and burden of ME/CFS in Canada. This will be meaningful for the assessment and planning of health services. This will inform the development of needs-based health policies and interventions.