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about the Ontario Student Drug Use and Health Survey (OSDUHS)

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Need help understanding the data contained on this site?

  • For each data source, information about data collection and analytical methods, limitations, the citation and additional resources can be found on the Data Sources and Methods page.

The Ontario Student Drug Use and Health Survey (OSDUHS) is a survey of over 10,000 grade 7 to 12 students in Ontario, run by the Centre for Addiction and Mental Health (CAMH). The survey collects information about health and substance use, including physical and mental well-being, and perceptions, awareness and use of alcohol, tobacco and drugs.


Original Source: Centre for Addiction and Mental Health (CAMH)
Cite as: Ontario Student Drug Use and Health Survey, 2013, 2015, 2017, Centre for Addiction and Mental Health. Region of Peel - Peel Public Health.


Data Collection Methods

  • The survey is conducted every two years and has been running since 1977. The OSDUHS offers the opportunity for Ontario public health units to purchase an additional student sample in their region (includes approximately 1,500 additional students). This allows partnering health units to provide more precise regional estimates on key health measures of interest. Peel Public health purchased an additional regional sample starting in 2013.
  • This type of survey draws a sample from the population of interest (in this case, Ontario students in grades 7 to 12) and collects responses from students in the sample.
  • OSDUHS uses a stratified two-stage cluster sample design to recruit Ontario students. The sampling frame is a list of all publicly-funded schools in Ontario with any students in grades 7 to 12, provided by the Ontario Ministry of Education. Grade 7 and 8 schools with less than 30 students and secondary schools with less than 80 students were not eligible for selection. Schools were divided into strata geographically. Within each stratum schools were selected with probability proportional to size, using systematic sampling (without replacement).
  • The target population for the OSDUHS is students in grades 7 to 12 enrolled in Ontario’s four publically funded school systems (i.e., English public, English Catholic, French public, and French Catholic). This captures approximately 92% of Ontario students in grades 7 to 12. The following students are not covered by the sampling frame (8% of all students):
    • students enrolled in private schools or those who are homeschooled;
    • youth who are institutionalized for correctional or health reasons;
    • students schooled in First Nation reserves, military bases or in remote northern regions of Ontario; and
    • students who have dropped out and are no longer enrolled in school.
  • Within a selected school, classes were randomly selected within grades and students were asked to complete a self-administered paper-and-pencil questionnaire during a regularly-scheduled classroom period.
  • Additional details about the OSDUHS including instrument design, sampling and other measurement concepts can be found on the CAMH website.

Release Guidelines

  • For data on the Health Status Data website, release guidelines based on the Coefficient of Variation (CV) were used. These guidelines are recommended by Statistics Canada.
    • CV between 0 and 16.5: Releasable
    • CV between 16.6 and 33.3: Use with caution. In this scenario, the letter ‘a’ is presented within the data table, with a footnote stating ‘Use estimate with caution’
    • CV greater than 33.3: Not releasable. In this scenario, the acronym ‘NR’ is presented in the data table, with a footnote stating ‘Not releasable due to small numbers’
  • Note: The CAMH reports also suppress estimates with a denominator of less than 50 observations or for estimates with percentages less than 0.5%. Given the sample size in Peel, data were suppressed if the observations in the numerator were less than 10.

Data Analysis Methods

  • All OSDUHS data presented on the website were design-based and statistical tests were design-adjusted using Taylor series linearization.
  • By applying population weights provided by CAMH, measures such as percentages and totals (referred to as population estimate in the tables on this website) are therefore estimates of the total population.
  • 95% confidence intervals are also presented in the data tables. The confidence interval presents a lower and upper range of values, which contains the true value of the percentage for the whole population 95% of the time, or 19 times out of 20.
  • When the 95% confidence interval of one percentage does not overlap with that of another percentage, the difference between the percentages is considered statistically significant (i.e., very unlikely to be due to chance). Throughout the key messages, the terms “significantly higher” or “significantly lower” are used to describe data that are significantly higher or lower based on the 95% confidence intervals that do not overlap with one another.
  • If students did not respond to the question, the missing responses were not included in the calculation of the percentages. If 5% or more of total respondents did not respond to a question, a note below the table will indicate the amount (percentage) of missing responses to the question. This may be presented as a range to cover multiple years of data.
  • A number of questions in the OSDUHS were asked of a random half sample of students. Population estimates for these questions have been doubled.
  • Data quality enhancements were made by CAMH. For example, students were removed from the final dataset if they: did not report their age; did not report their sex; reported use of a fictitious drug called ‘adrenochromes’; reported using all core illicit drugs 40 or more times during the last year, which is referred to as ‘faking bad’; or did not respond to half or more of the core substance use survey questions.

The OSDUHS data tables show the estimates of the percentage and population, as well as the 95% confidence intervals for each question of interest. Responses to the questions are usually grouped by the following demographic variables, as well as sex and grade:

Immigrant Status
Question: How long have you lived in Canada?

    Immigrant status categories:

  • Recent Immigrant – students who reported living in Canada 'ten years or less'.
  • Long-term immigrant – students who reported living in Canada '11 years or more'.
  • Non-immigrant – students who reported living in Canada 'all my life'.

Question: Which of the following best describes your background? (You may choose more than one category.) Are you…?

  • White (for example, British, French, Italian, Portuguese, Ukrainian, Russian, Israeli)
  • Chinese
  • South Asian (for example, East Indian, Pakistani, Bangladeshi, Sri Lankan)
  • Black (African, Caribbean, North American)
  • Aboriginal (First Nations, Inuit, Métis, non-status Indian)
  • Filipino
  • Latin American, Central American, South American (for example, Mexican, Brazilian, Chilean, Guatemalan, Venezuelan, Colombian, Argentinian, Salvadorian, Costa Rican)
  • Southeast Asian (for example, Vietnamese, Cambodian, Indonesian, Malaysian, Laotian)
  • West Asian or Arab (For example, Egyptian, Saudi Arabian, Syrian, Iranian, Iraqi, Lebanese, Afghani, Palestinian)
  • Korean
  • Japanese
  • Not sure

Ethnicity categories:

Ethnicity shown in
OSDUHS tables
Responses to Ethnicity
question on OSDUHS survey
White White
Southeast Asian Southeast Asian
South Asian South Asian
Black Black
Aboriginal Aboriginal
Latin American Latin American
Central American
South American
West Asian or Arab West Asian or Arab
Multiple Selected more than one ethnicity (including those who selected both a specific category and ‘not sure’)


  • The sampling frame excludes students not enrolled in Ontario’s four publically funded school systems. This represents approximately 8% of students between grades 7 to 12.
  • The list of schools used to select the sampling frame would not include any schools built after the date that the most current list was produced. For example, schools selected for the 2013 ODSUHS cycle would not include schools built after 2009/2010. This would have the largest impact on high growth areas.
  • Response rates have decreased since the OSDUHS inception in 1977 and are due to both non-consent and absenteeism. Students who did not have consent to complete the survey, or who were absent from class on the day of the survey may be different than students who complete the survey.
  • Student responses may be subject to social desirability bias, especially for questions addressing sensitive topic areas, including alcohol and drug use.


  1. Pollard J, Ornstein M, Northrup D, McCague H. The design and implementation of the Ontario Student Drug Use and Health Survey 2013, Centre for Addiction and Mental Health. Toronto (ON): Institute for Social Research, York University; 2013 Oct. 173 p.
  2. Boak A, Hamilton HA, Adlaf EM, Mann RE. Drug Use among Ontario students, 1977-2013: Detailed OSDUHS findings [Internet]. Toronto (ON): Centre for Addiction and Mental Health; 2013 [cited 2016 Nov 3]. CAMH Research Document Series No.: 36. Available from:
    https://www.camh.ca/en/research/news_and_publications/ontario-student-drug-use-and-health-survey/Documents/2013 OSDUHS Docs/2013OSDUHS_Detailed_Drug.
  3. Boak A, Hamilton HA, Adlaf EM, Beitchman JH,Wolfe D, Mann RE. The mental health and well-being of Ontario students, 1991-2013: Detailed OSDUHS findings [Internet]. Toronto (ON): Centre for Addiction and Mental Health; 2014 [cited 2016 Nov 3]. CAMH Research Document Series No. 38.: Available from:
    https://www.camh.ca/en/research/news_and_publications/ontario-student-drug-use-and-health-survey/Documents/2013 OSDUHS Docs/2013OSDUHS_Detailed_Drug.

Last updated: February 12, 2019

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