Ontario Marginalization Index (ON-Marg)

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

The Ontario Marginalization Index (ON-Marg) shows socioeconomic, 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.

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 birth weight.

ON-Marg is updated every five years when Census of Canada data is collected, 2021 being the most recent update. 

Download the
ON-Marg Tool ON-Marg
User Guide ON-Marg
Survey of Users

Contact us

Dr. Flora Matheson
Principal Investigator

Flora.Matheson@unityhealth.to

ON-Marg can be used for:

 Identifying service gaps and where rates of hospitalizations for a particular disease, such as diabetes, are high and additional services might be needed.

Creating funding formulae for services such as primary care.

Monitoring changes in areas over time to look for improvement or to identify areas that may be in decline.

In the health sector there is a long history of using small area indexes to describe the relationship between marginalization and health outcomes; greater marginalization is associated with higher mortality rates and higher rates of many diseases