Denominator Guidelines for Health Surveillance in First Nations Populations in Canada - Executive Summary

Finding an appropriate denominator to calculate rates for First Nations health data has been a long-standing challenge.  This report provides guidance to help health portfolio epidemiologists, analysts and researchers select the appropriate denominator for rate calculations.  This guidance is based on a comparative analysis of three existing major data sources:  Aboriginal Affairs and Northern Development Canada's Indian Register, Health Canada's Status Verification System and Statistics Canada's Census.

This analysis led to the development of recommendations to identify the most appropriate source to use in given circumstances, and to generate awareness of the advantages and limitations associated with each option.  

Recommendations:

Use the Indian Register (IR) for calculating rates for the Registered Indian population on and/or off reserve.  The adjusted IR is the preferred denominator option for Indian Act registrants.

Limitations

• Late reporting of births and deaths in unadjusted data; however, adjusted IR counts can provide a more complete picture of the Registered Indian population at the national and regional level. 
• Community-level data are not available from the IR.
• Inability to systematically record mobility of the population moving on and off reserve.
• Access requires Aboriginal Affairs and Northern Development Canada (AANDC) permission which can take time.

Use the Status Verification System (SVS) data when rates for those entitled to receive non-insured health benefits are required.  The SVS provides the ideal denominator for the calculation of utilization rates of non-insured health benefits.

Limitations

• The SVS is a subset of data from the IR and late reporting of births and deaths is an issue.  SVS data are not adjusted for late reporting.
• Like the Indian Register, information on moves on and off reserve is not updated regularly.

Use census counts when data from other census variables serve as the numerator (education, labour, income, etc.).  The census is the only population source for those who identify as First Nations but who are not registered with AANDC and ought to be used for denominators for this population. In addition, detailed census data are available for many First Nations communities. 

Limitations

• The most significant limitation of this source is the exclusion of over 80,000 people living on a reserve that did not take part in the 2006 Census or who were missed in reserves that did participate. This is a particular concern for Ontario and Quebec and to some extent, Alberta.
• Data are based on self-identification of Status and First Nations identity.
• Data quality issues around the voluntary 2011 National Household Survey are not yet known.
• Data may be out of date as a census is conducted every five years and intercensal estimates of First Nations and Registered Indian populations are not available.

This report also calls attention to the need to improve the availability and quality of the denominator data from various sources.