Estimating how many people in Canada inject drugs
People who inject drugs that are not prescribed to them often experience complex health challenges and have a difficult time accessing healthcare. To make sure we can provide the services and resources that better support this community, we first need to know how big the community is and where they live.
That’s why the Public Health Agency of Canada has created the report, Estimating the population size of people who inject drugs in Canada, which estimates, in 2021:
- How many people injected drugs recently (within the past 12 months, broken down by sex assigned at birth)
- How many people have ever injected drugs (broken down by sex assigned at birth and geographic region)
The process for creating these estimates involved several steps, so let’s review them in greater detail.
How we estimate the number of people who inject drugs
Step 1: We began by selecting a sample of people that represented the Canadian population. In this case, we used Statistics Canada’s Canadian Community Health Survey (CCHS) as our sample. The CCHS is a national survey that collects health-related information from a group of people that represents about 97% of the Canadian population.
Step 2: Using information from the CCHS, we learned how many people in the sample had experience injecting drugs. We also gathered other information from the sample, like their sex and where they live. With this data, we calculated what percentage of the sample a) had injected drugs recently, and b) had ever injected drugs.
Step 3: To apply these results to the whole population, we multiplied the percentage of the sample that had experience injecting drugs by the total number of people in the population. We knew the total population by referring to the Statistics Canada’s national population size estimates for 2021.
Step 4: Since the CCHS doesn’t represent everyone in Canada, we used a similar approach to estimate injection drug use among groups not included in the CCHS – specifically:
- First Nations Peoples living in a First Nations community;
- People who are in prison;
- Active military personnel; and
- People experiencing homelessness or unstable housing.
To estimate injection drug use for each of the first three groups, we repeated steps 1 to 3 with each population. We used data sources as shown below to identify our samples:
| Population | Sample source | Population size source |
| First Nations Peoples living in First Nations communities | PHAC: Tracks surveillance survey | Statistics Canada: Census of population |
| People who are incarcerated | Correctional Service Canada: Prevalence of injection drug use among male offenders and Correctional Service Canada: Self-reported physical health status of incoming federally sentenced women offenders | Statistics Canada: Population size estimate of people who are incarcerated in federal prison |
| Active military personnel | Statistics Canada: CCHS* * Data on injection drug use in the military were unavailable. Instead, we assumed that injection drug use among active military personnel occurred at the same rate as the general population. This meant we could use the proportion calculated in step 1 and apply it to this group of people. | Canadian Armed Forces: Population size estimate of Regular Force members |
Data were not directly available for the fourth group, people experiencing homelessness or unstable housing. Instead, we used a sample of people who inject drugs from the Tracks surveillance survey. We learned what percentage of this sample had reported unstable housing. Then, we multiplied that amount by the estimated number of people who injected drugs in the general population. This gave us an estimated number of people who injected drugs and experienced homelessness or unstable housing.
Step 5: Once we had estimates for the general population and the additional groups, we added them together to get an overall estimate of the number of people who inject drugs in Canada.
Step 6: People may not feel comfortable reporting drug use on a government survey because of fear of judgment, legal issues or stigma. This means the estimates might be lower than the actual number. We reviewed research that compared rates of self-reported injection drug use to lab test results. This helped us determine how much underreporting might have been happening, and we used this to adjust the estimates.
Additionally, the initial estimates grouped together people who inject only steroids with people who inject other drugs. We know there are important differences in lifestyle and injecting practices between the two groups. To provide a more complete picture of injection drug use, the final estimates show counts with and without people who inject only steroids.
Findings
How many people have recently injected drugs
We estimate, as of 2021, 100,300 people had recently injected drugs. After removing people who inject steroids only, we estimate that 99,700 people had recently injected drugs.
Broken down by sex, we estimate that in Canada:
| Total population | Males | Females |
| 100,300 people had recently injected drugs | 3 out of 4 people who had recently injected drugs were male | 1 out of 4 people who had recently injected drugs were female |
| 0.31% of the total population has recently injected drugs | 0.47% of the total male population has recently injected drugs | 0.16% of the total female population has recently injected drugs |
| 1 in 320 people have recently injected drugs | 1 in 213 males have recently injected drugs | 1 in 625 females have recently injected drugs |
How many people have ever injected drugs
We estimate, as of 2021, 388,400 people had ever injected drugs. After removing people who inject steroids only, 350,200 people had ever injected drugs.
Broken down by sex, we estimate that in Canada:
| Total population | Males | Females |
| 388,400 people had ever injected drugs | 3 out of 4 people who have ever injected drugs were male | 1 out of 4 people who have ever injected drugs were female |
| 1.22% of the total population has ever injected drugs | 1.84% of the total male population has ever injected drugs | 0.61% of the total female population has ever injected drugs |
| 1 in 82 people have ever injected drugs | 1 in 54 males have ever injected drugs | 1 in 164 females have ever injected drugs |
We also broke down the estimate by region:
| Region | Number of people | Percentage of total population |
| Territories (YK, NU, NWT) | 2,400 | 2.47% |
| Saskatchewan | 21,600 | 2.19% |
| Manitoba | 22,400 | 1.93% |
| British Columbia | 74,800 | 1.68% |
| Alberta | 48,200 | 1.33% |
| Quebec | 48,200 | 1.04% |
| Ontario | 124,300 | 1.00% |
| Atlantic (NS, NB, PEI, NL) | 19,300 | 0.92% |
Additional details
Precision
Within the full report, estimates will be shown like this: 388,400 (338,900 – 436,500). The numbers in brackets are what we call a “plausible range”. Since the data may not be perfectly accurate, we use this range to show the possible variation in the estimate.
Geographic range
In order for a sample to be representative, it must be large enough to capture the true diversity of the population. However, in some provinces, the size of the sample we had was too small to make an accurate estimate on its own. In these cases, these smaller samples were combined with nearby provinces to create larger geographic regions.
Limitations
As with all research, the process we used to calculate these estimates is not perfect. We used the best data available, but there were still some gaps in what we knew. In those cases, we had to make some assumptions to fill in the missing pieces, which means the estimates may not be perfectly accurate. As we continue to improve how we collect data, we’ll be able to adjust our approach and make future estimates more accurate.