Survey on Mental Health and Stressful Events (SMHSE)

Detailed information for 2021





Record number:


The purpose of the Survey on Mental Health and Stressful Events is to collect data from Canadians to better understand how stressful events can impact a person's mental health.

Data release - May 20, 2022


The survey will also cover mental health status and well-being, post-traumatic stress disorder (PTSD), social support and healthy behaviours, and the access to and use of mental health services.

The data will be used by the Public Health Agency of Canada and may be used by other government organizations to inform the delivery of mental health services and support.

Reference period: 2021

Collection period: August 3 to December 10, 2021


  • Health
  • Health care services
  • Lifestyle and social conditions
  • Mental health and well-being

Data sources and methodology

Target population

The target population for the survey was people aged 18 years and older, living in the 10 provinces. Specifically excluded were people living in the three territories, people living on reserve, people living in institutions and people living in collective dwellings.

The survey population was built from the Dwelling Universe File (DUF) from which institutions and collective dwellings are excluded. The survey population consisted primarily of dwellings with mailable addresses. Approximately 95.2% of the dwellings on the frame had mailable addresses.

Instrument design

The content for the Survey on Mental Health and Stressful Events (SMHSE) electronic questionnaire was drafted in consultation with Statistics Canada's Centre for Population Health Data, as well as the Public Health Agency of Canada.

The questionnaire underwent cognitive testing in the form of in-depth interviews in both of Canada's official languages, conducted by Statistics Canada's Questionnaire Design Resource Centre. The goal of the qualitative study was to test the survey content.


This is a sample survey with a cross-sectional design.

The frame is the Dwelling Universe File (DUF), which is a snapshot of the Address Register database at a given point in time. The Residential Telephone File (RTF) was used to obtain telephone numbers for non-response follow-up. The March 2021 vintage of the DUF and the April 2021 vintage of the RTF were used. Institutions, collective dwellings and dwellings on Indigenous reserves were excluded.

Sampling unit
The SMHSE sample has a two-stage design: the sampling unit for the first stage is the dwelling, and the sampling unit for the second stage is the person.

Stratification method
The SMHSE frame was stratified by province, and a simple random sample of dwellings was selected independently within each province.

Sampling and sub-sampling
Sufficient sample was allocated to each of the provinces so that the survey could produce national estimates of good quality. An initial sample of 35,000 dwellings was selected and sent to collection.

Data sources

Data collection for this reference period: 2021-08-03 to 2021-12-10

Responding to this survey is voluntary.

Data are collected directly from survey respondents.

Data are collected through an electronic questionnaire (EQ) or through computer assisted telephone interviewing (CATI).

View the Questionnaire(s) and reporting guide(s) .

Error detection

Electronic files containing the daily transmissions of completed respondent survey records were combined to create the "raw" survey file. Before further processing, verification was performed to identify and eliminate potential duplicate records and to drop non-response and out-of-scope records.

In addition, some out-of-scope respondent records were found during the data clean-up stage. All respondent records that were determined to be out-of-scope and those records that contained no data were removed from the data file.

After the verification stage, editing was performed to identify errors and modify affected data at the individual variable level. The first editing step was to identify errors and determine which items from the survey output needed to be kept on the survey master file. Subsequent to this, invalid characters were deleted and the remaining data items were formatted appropriately.


This methodology type does not apply to this statistical program.


The Survey on Mental Health and Stressful Events (SMHSE) is a probability survey. As is the case with any probability survey, the sample was selected so as to be able to produce estimates for a reference population. Therefore, each unit in the sample represents a certain number of units in the population in addition to themselves. This number is referred to as the survey weight.

1) Each selected dwelling is given an initial weight equal to the inverse of its selection probability from the sampling frame. Dwellings identified as out-of-scope during collection are dropped from the sample.

2) The weights for responding households are adjusted to represent the households that did not respond. Adjustment factors are calculated separately by province and dwelling type.

3) The household weights are calibrated so that the sum of the weights match provincial-level household size demographic counts.

4) Person weights are computed by multiplying the household-level weights by the inverse of the probability of selecting the person within the household.

5) The person weights are calibrated so that the sum of the weights matches demographic population counts at the provincial level by census metropolitan area and at the regional level by age group by gender level.

To estimate variances directly, one set of 1,000 bootstrap weights was also created and made available in a separate file.

The Generalized Estimation System was used to generate the survey weights and bootstrap weights.

Quality evaluation

While rigorous quality assurance mechanisms are applied at all stages of the statistical process, the validation and detailed review of data by statisticians is the ultimate verification of quality prior to release. Many validation measures were implemented, they include:

a. Verification of estimates through cross-tabulations
b. Consultation with stakeholders internal to Statistics Canada
c. Consultation with external stakeholders

Disclosure control

Statistics Canada is prohibited by law from releasing any information it collects that could identify any person, business, or organization, unless consent has been given by the respondent or as permitted by the Statistics Act. Various confidentiality rules are applied to all data that are released or published to prevent the publication or disclosure of any information deemed confidential. If necessary, data are suppressed to prevent direct or residual disclosure of identifiable data.

Revisions and seasonal adjustment

This methodology type does not apply to this statistical program.

Data accuracy

Survey errors come from a variety of different sources. One dimension of survey error is sampling error. Sampling error is defined as the error that arises because an estimate is based on a sample rather than the entire population. Sampling error can be expressed through a confidence interval or coefficient of variation.The quality of estimates produced with SMHSE data is measured with the confidence intervals (CI), produced using bootstrap weights. The CI range will depend on the domain of interest and the prevalence of the characteristic.

The following are approximate sampling error estimates for Canada level estimates. These are based on average results; these are not results for a specific variable.

-Approximate length of 95% confidence intervals for a proportion of 50% (Canada level): 1.9%
-Approximate length of 95% confidence intervals for a proportion of 10% (Canada level): 1.1%
-Approximate coefficients of variation for a proportion of 10% (Canada level): 2.73%

Response rates
The response rate for the Survey on Mental Health and Stressful Events was 50.80%.

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