Report on Autism Prevalence in Canada Mirrors Vaccination Coverage Rates in Different Provinces

IN BRIEF

First report on autism prevalence in Canada shows Newfoundland and Labrador have highest numbers of kids with autism. They also have the highest vaccine coverage rates.  The Yukon had the lowest autism rates and the lowest vaccine coverage. 

By Anke Zimmermann, BSc, FCAH

National Autism Spectrum Disorder Surveillance System (NASS)

The National Autism Spectrum Disorder Surveillance System (NASS) just released it first report ever: Autism Spectrum Disorder Amoung Children and Youth in Canada 2018. This surveillance report is “Made in Canada” and provides a first reporting of national data and information to improve our understanding of Autism Spectrum Disorder (ASD) in Canada. It is based on data collected in 2015.

NASS compiles administrative data from the health, education and social services sectors for children and youth (aged 5-17 years) who have a confirmed ASD diagnosis.

Overall incidence rate of autism was one in 68 children, with the age group of 1-4 having grown the most. The report found that boys were 4.1 times more likely to be affected as girls. 

Seven of Canada’s 13 provinces and territories provided information for 2015, including six provinces (British Columbia, New Brunswick, Newfoundland and Labrador, Nova Scotia, Prince Edward Island and Quebec) and one territory (Yukon). As the figure below shows, ASD prevalence in 2015 varied among the seven regions, with the highest prevalence noted in the three provinces of Newfoundland and Labrador (1 in 57), Prince Edward Island (1 in 59) and Quebec (1 in 65). In comparison, prevalence was substantially lower in the Yukon territory (1 in 125).

Autism Rates in the Different Provinces

Why are the numbers in Labrador and Newfoundland the highest?

Well, there is another interesting Canadian report available on vaccination coverage rates in the different provinces in Canada, called Vaccine Coverage in Canadian Children, published in 2013 by the very same Public Health Agency of Canada. 

Guess who had the highest vaccination rates? Labrador and Newfoundland. And the lowest? The Yukon. An very close mirror to the autism rate statistics. Please see below a rendering of their table for MMR vaccine uptake. You can also read the whole report here. 

TABLE 7: Estimated vaccination coverage for measles, mumps, and rubella by two years of age across provinces and territories—childhood National Immunization Coverage Survey, 2013, by 2 years of age

Measles, Mumps Rubella, percentages vaccinated

                                                                Measles 1-2 doses Mumps 1-2 doses Rubella 1- 2 doses
Newfoundland and Labrador 95.1                                95.1                              95.1 
Prince Edward Island                  90.2                                90.2                              90.2  
Nova Scotia                                       85.8                                85.5                              85.5
New Brunswick                              92.3                                 92.3                             92.3 
Québec                                                90.6                                 90.6                             90.6 
Ontario                                                92.6                                 92.0                             92.0
British Columbia                            86.9                                 86.9                             87.6 
Yukon                                                    85.2                                 85.2                             85.2 

Canada overall                                 89.6                                 89.2                              89.2

Other Vaccines

Vaccine coverage for other vaccines was very similar with highest vaccination coverage for all  vaccines in Labrador and Newfoundland and lowest in the Yukon, with the other provinces in between. You can read the whole vaccine coverage report right here.  

Correlation and Causation

This is a very interesting finding with as yet unknown repercussions.  Although we all know that correlation does not equal causation, a plausible association between two variables is generally an important clue worth investigating.

The substantially lower ASD prevalence in a region that happens to have markedly lower vaccine coverage is one such clue.  

It would behoove Canada’s public health officials to take a closer look at their own data and start taking meaningful steps to study vaccinated versus unvaccinated children in order to shed more light on these concerning issues.

Anke Zimmermann, BSc, FCAH