Ontario Marginalization Index (ON-Marg)

An Ontario-specific version of the Canadian Marginalization Index (CAN-Marg), which has been in use since 2006.


Neighbourhoods and Health

A small-area based measure of marginalization widely used by policy planners and researchers in Ontario.

The Ontario Marginalization Index shows socio-economic, ethno-racial, age-based and social differences in small and large regions of Ontario. It can be used to compare health inequities over geographic location and over census years. It has been used by The Hospital for Sick Children, Peel Public Health, and Public Health Ontario, among other organizations.

Visit the Ontario Community Health Profiles Partnerships website to download the tool.

ON-Marg has been used for:

  • Planning and needs assessment: For example, if the goal is to identify service gaps, ON-Marg has been used to identify where rates of hospitalizations for a particular disease, such as diabetes, are high and additional services might be needed.
  • Resource allocation: For example, marginalization indices have been used in funding formulae for primary health care services.
  • Monitoring of inequities: For example, ON-Marg has been used to monitor changes in areas over time to look for improvement or to identify areas that may be in decline.
  • Research: For example, there is a long history in the health sector of using small areas to better understand the relationship between marginalization and health outcomes at the local level; greater marginalization is associated with higher mortality rates and higher rates of many diseases.

The Index was developed using a theoretical framework based on previous work on deprivation and marginalization. It was then empirically derived using principal component factor analysis. Learn more about our methods.

ON-Marg has been demonstrated to be stable across time periods and across different geographic areas (e.g., cities and rural areas). It has also been demonstrated to be associated with health outcomes including: hypertension, depression, youth smoking, alcohol consumption, injuries, body mass index and infant birthweight.

ON-Marg is updated every five years when Census of Canada data is collected. ON-Marg will be updated for Census 2021.

In 2020, MAP Centre for Urban Health Solutions at St. Michael’s Hospital, Unity Health Toronto, with input from multiple partners, developed a survey to send to users of the Ontario Marginalization (ON-Marg) Index. The Index remains one of the most widely used indices for health planning and research in Ontario. With the help of a practicum student, the team put together and distributed a survey to learn about those using the Index, and their reasons for doing so. The report summarizes the findings of this survey, showing the value this data brings to multiple sectors. 

Read the report here.

  • Matheson, F. I., Dunn, J. R., Smith, K. L., Moineddin, R., & Glazier, R. H. (2011). Ontario Marginalization Index (ON-Marg): User Guide: St. Michael’s Hospital.
  • Matheson, F. I., LaFreniere, M. C., White, H. L., Moineddin, R., Dunn, J. R., & Glazier, R. H. (2011). Influence of neighborhood deprivation, gender and ethno-racial origin on smoking behavior of Canadian youth. Preventive medicine, 52(5), 376-380.
  • Matheson, F. I., Moineddin, R., Dunn, J. R., Creatore, M. I., Gozdyra, P., & Glazier, R. H. (2006). Urban neighborhoods, chronic stress, gender and depression. Social science & medicine, 63(10), 2604-2616.
  • Matheson, F. I., Moineddin, R., & Glazier, R. H. (2008). The weight of place: a multilevel analysis of gender, neighborhood material deprivation, and body mass index among Canadian adults. Social science & medicine, 66(3), 675-690.
  • Matheson, F. I., Smith, K. L., Moineddin, R., Dunn, J. R., & Glazier, R. H. (2013). Mental health status and gender as risk factors for onset of physical illness over 10 years. Journal of epidemiology and community health, jech-2013-202838.
  • Matheson, F. I., White, H. L., Moineddin, R., Dunn, J. R., & Glazier, R. H. (2010). Neighbourhood chronic stress and gender inequalities in hypertension among Canadian adults: a multilevel analysis. J Epidemiol Community Health, 64(8), 705-713. doi:10.1136/jech.2008.083303
  • Matheson, F. I., White, H. L., Moineddin, R., Dunn, J. R., & Glazier, R. H. (2012). Drinking in context: the influence of gender and neighbourhood deprivation on alcohol consumption. Journal of epidemiology and community health, 66(6), e4-e4.
  • Smith, K. L., Matheson, F. I., Moineddin, R., & Glazier, R. H. (2007). Gender, income and immigration differences in depression in Canadian urban centres. Canadian Journal of Public Health/Revue Canadienne de Sante’e Publique, 149-153.
  • Urquia, M. L., Frank, J. W., Glazier, R. H., Moineddin, R., Matheson, F. I., & Gagnon, A. J. (2009). Neighborhood context and infant birthweight among recent immigrant mothers: a multilevel analysis. Am J Public Health, 99(2), 285-293.
  • White, H. L., Matheson, F. I., Moineddin, R., Dunn, J. R., & Glazier, R. H. (2011). Neighbourhood deprivation and regional inequalities in self-reported health among Canadians: Are we equally at risk? Health & place, 17(1), 361-369.

Neighbourhoods and Health

Dr. Flora Matheson

Dr. Flora Matheson is a medical sociologist, mental health and addictions specialist, and the St. Michael's Hospital Chair in Homelessness, Housing and Health. Using a gender lens, she investigates the social determinants of mental health, substance and alcohol use, homelessness, problem gambling, and criminal justice involvement.

Dr. James Dunn

Dr. James Dunn studies the urban built environment and health: how changes in our neighbourhoods and communities can affect us, and the real-life impacts of urban planning and social policies.

Dr. Rick Glazier

A family doctor and leader in his field, Dr. Rick Glazier investigates primary care through a health-equity lens: revealing gaps in care, and examining the implications of primary-care reform for traditionally under-served groups. He is an expert in linking geographic methods with administrative health data to help identify priority areas for services and care.


  • Trevor van Ingen (Public Health Ontario)
  • Dr. Rahim Moineddin
    University of Toronto


  • Gary Moloney, Spatial Analyst


  • St. Michael’s Hospital
  • Public Health Ontario
  • Social Sciences and Humanities Research Council of Canada


  • Public Health Ontario

Contact Info

Dr. Flora Matheson

Principal Investigator