Indigenous Peoples Thematic Series
Infant mortality rates of Indigenous populations in Canada, 1994-1996, 2004-2006 and 2014-2016

1. Introduction

The infant mortality rate (IMR) is an important mortality indicator, and its determinants are associated with the living conditions and the socioeconomic development of populations.^Note 1 Statistics Canada publishes annual estimates of IMRs for the country and the provinces and territories.^Note 2 However, the methodology cannot be used to obtain disaggregated results for Indigenous populations because the data sources—the Canadian Vital Statistics - Death database (CVSD) and the Demographic Estimates Program—do not contain information on Indigenous identity. The following document summarizes the data sources and methods used to compute IMRs for various Indigenous populations using an alternative dataset, the Canadian Birth-Census Cohorts (CanBCCs).

2. Data sources and methods

The CanBCCs consists of linkages of births, stillbirths and infant deaths from the Canadian Vital Statistics - Birth database (CVSB)^Note 3 and the CVSD^Note 4 with the long-form census questionnaires. They were created to examine patterns and disparities in perinatal health across socioeconomic and ethnocultural groups in Canada.^Note 5 The cohorts are made of birth, stillbirth and infant death events that occurred in the two years prior to Census Day that are linked to respondents from the Census long-form questionnaire in order to obtain detailed characteristics of the parents, such as Indigenous identity. The IMR is computed as the number of deaths having occurred in the first year of life divided by the total number of these births. Estimates of variance of the IMR were obtained using the method of balanced repeated replication described by Phillips (2004).^Note 6 Three CanBCCs have been produced through linkages with the 1996, 2006, and 2016 censuses. Table 1 describes the coverage, reference periods, and sample sizes of each of the three CanBCC cohorts.

The CanBCCs exclude the population living in institutional dwellings at time of the census, such as correctional facilities, nursing homes, and group homes, as well as the population living in non-institutional collective dwellings such as rooming houses, shelters, and hotels, and the population with no fixed address (i.e., unhoused). While there are indications that Indigenous populations tend to be overrepresented among institutional and collective populations, ^Note 7 IMRs computed using the CanBCCs tend to be close to those computed directly from the CVSB and CVSD at the national level, which suggests that the exclusion of the population living in institutional and collective dwellings in the CanBCCs does not result in significant bias in the estimation of the IMR.^Note 8

Cohort weights, designed to account for the census sampling design, census nonresponse, and missed linkages between the birth and census databases, the latter of which represent a reduction of about 10% in cohort sizes, have been generated to ensure that estimates can be considered representative of the population of private households at the time of census collection. Series of bootstrap weights are also available to account for the variability arising from sampling, nonresponse, the linkage process and the stochastic variability inherent in vital events. More information about CanBCC data can be found in Bushnik et al. (2016).^Note 9

3. Indigenous identity populations

As most deaths before the age of 1 in the CanBCCs occurred before Census Day, the Indigenous identity of deceased babies is not available in most cases. For example, in the 2006 CanBCC, information on identity is missing in 97% of cases; by contrast, the information is missing for less than 2% of babies who survived up to age 1. When missing, the identity of babies is imputed based on the information about the identity of the linked mothers and fathers. In cases where the mother and father have distinct identities, children’s records are cloned to create one record with each identity, and the weights are divided by two. The following categories are used:

Total –population living in private households.

1. Total Indigenous population: This category includes persons who identified as First Nations (North American Indian), Métis and/or Inuk (Inuit) and/or those who reported being Registered or Treaty Indians (that is, registered under the Indian Act of Canada), and/or those who reported having membership in a First Nation or Indian band. Individuals who self-identified with more than one Indigenous group are included in this category but excluded from the categories below.
   1. First Nations, Registered or Treaty Indians: Includes persons who identified as First Nations (North American Indian) and not as Métis or Inuk (Inuit) and reported a Registered or Treaty Indian status.
      1. First Nations, Registered or Treaty Indians living on reserve: Includes the subset of the First Nations, Registered or Treaty Indian population who were living on reserve at the time of the census.
      2. First Nations, Registered or Treaty Indians living off reserve: Includes the subset of the First Nations, Registered or Treaty Indian population who were living off reserve at the time of the census.
   2. Métis: Includes persons who identified as Métis and not as First Nations (North American Indian) or Inuk (Inuit).
   3. Inuk (Inuit): Includes persons who identified as Inuk (Inuit) and not as First Nations (North American Indian) or Métis.
2. Non-Indigenous people: Includes persons who did not identify as First Nations (North American Indian), Métis or Inuk (Inuit), and also did not report having Registered or Treaty Indian status or membership in a First Nation or Indian band.

Note that estimates for the population identifying as First Nations (North American Indian) and not as Métis or Inuk (Inuit), and who also did not report a Registered or Treaty Indian Status, are not included due to insufficient sample size.

4. Limitations

Because death is a relatively rare event, IMR estimates are often based on small sample sizes and are thus associated with large variances. In this context, it is sometimes difficult to draw definitive conclusions about trends over time, or about differences between population groups. Small sample sizes also limit the ability to publish disaggregated estimates for small population groups or geographical regions.

It is also important to note that some portion of the changes in IMRs observed over time may be attributable not to changes in mortality, but to other sources of heterogeneity. This includes changes made to the definition of reserves over time and changes to the list of incompletely enumerated reserves, for which no data are available in the census.^{Note 10Note 11} Another source is the mobility of responses in the census, which is defined by changes in how people respond to questions about Indigenous identity over time.^Note 12 Because of this phenomenon, a portion of the changes observed in health outcomes among a population group over time may be attributable solely to changes in the composition of this group.^Note 13 Differences in the composition of the population affect comparisons not only over time, but across population groups. Multiple factors can explain the differences in life expectancy between Indigenous and non-Indigenous populations, such as differences in education or income^Note 14 or place of residence.^Note 15 Users are invited to consult Dion et al. (2024)^Note 8 for more details.