Research Blog: A snapshot of the health of the Canadian population through the Canadian Health Measures Survey
By Scott McLean, Health Statistics Division
The Canadian Health Measures Survey (CHMS) is an innovative Statistics Canada survey designed to obtain valuable, directly measured information about the health of Canadians. The CHMS is unique in Canada as it offers access to large amounts of health data from a nationally representative sample.
A Statistics Canada interviewer gathers data through a household interview, and fully trained health specialists collect physical measurements, such as anthropometric, cardiovascular and lung function measures in a mobile clinic. While at the mobile clinic, consenting participants give blood and urine samples. Specific aliquots of this collection are sent to reference laboratories to analyze nutritional, environmental, chronic disease and other biomarkers. Urine and blood samples are also sent to the National Microbiology Laboratory, in Winnipeg, to be added to the CHMS Biobank collection for use in future health studies. In addition, DNA is collected from participants who have provided consent specifically for this purpose.
All of the CHMS samples are collected and stored following a standardized protocol. Each vial (or tube) containing blood, urine or DNA samples at the Biobank is de-identified and labelled with only a barcode. No other information is associated with participant biospecimens at the Biobank. Under the authority of the Statistics Act, information on biospecimens and data remains secure and confidential.
After several years of collection, the CHMS has accumulated hundreds of thousands of samples of DNA, plasma, serum, whole blood, and urine from survey participants. This valuable resource is continuously expanding with each cycle of the CHMS. The Biobank samples are available from a wide age range and in varying volumes as summarized in the table below.
|Serum||3 to 79 years||0.5 ml and 1.0 ml|
|Plasma||3 to 79 years||0.5 ml|
|Whole Blood||3 to 79 years||0.8 ml and 1.0 ml|
|Urine||3 to 79 years||1.0 ml and 4.5 ml|
|DNA||14 to 79 years||1 µg|
Depending on the age range, the sample size per cycle varies from about 3,100 to 5,700 samples. Although the CHMS endeavors to use a standard pre-analytical protocol, it may vary from cycle to cycle as Biobank technologies and best practices evolve. For details on sample collection, processing and storage, researchers may request a user guide from the survey cycle(s) of interest.
Researchers must have funding in place to access the biospecimens. Statistics Canada has a fixed charge for each biobank matrix that is available. The estimated cost charged to the research project for a series from one survey cycle is listed below:
- 2ml serum, plasma, whole blood – $44,000
- DNA plates – $44,000
- 5 ml urine – $48,000
These are estimates only. If multiple series of samples are requested, the cost may be prorated to reflect the fact that some processes need only be carried out once for each project. The cost per series could increase as the number of analytical labs involved in the analysis of the biospecimens increases.
The CHMS biospecimens are available to any Canadian researcher who completes a review process. The review process assesses the feasibility, as well as the scientific merit to the proposal. Proposals should demonstrate how they would benefit from a national population survey of up to 5,700 participants. Applications are welcome from bona fide researchers who conduct research in Canada. Bona fide researchers are directed or supervised by a recognized public or private organization.
Since November 2013, a targeted call for proposals is held twice a year. Proposals can be submitted within a two‑month period, every spring and fall. Specific dates are announced at the time of the call for proposals, and also posted on various public forums including Twitter and Facebook.
Once the laboratory analysis of the CHMS Biobank samples has been completed, the data is processed at Statistics Canada. Researchers can then access their data at a Statistics Canada Research Data Centre (RDC) located on various university campuses across Canada. Here, researchers can merge their data with other variables collected as part of the CHMS. A Content Summary that outlines the information collected at the household, mobile clinic, and reference laboratories during past, present, and future cycles is available upon request.
Given the complex sampling design and sample weighting of the CHMS, researchers are advised to discuss their analyses, results and interpretations of survey data with Statistics Canada before publishing. Agency analysts are available at the RDCs to provide support in this regard. Workshops are also held in the Ottawa area, which provide instruction on analytical techniques using SAS software and a synthesized data file that reflects what is available at the RDCs.
We would like to hear from you if you are interested in participating to one of our workshops. We are exploring the demand for our workshops to determine the interest for possible expansion across Canada.
Biobank researchers have one year to analyze their data and to publish the results in a peer‑reviewed journal before the dataset becomes available to other researchers who may request access through the RDC.
On Wednesday, October 29, 2014, Statistics Canada will release the first of several cycle 3 data releases of the CHMS. It will focus on household and physical measures of Canadians (2012 to 2013). This release will include data on height and weight, blood pressure and spirometry (lung health).
You are invited to chat with an expert on these findings on October 30, 2014, from 1:30 and 2:30 p.m., EDT. We look forward to chatting with you!
Scott McLean is the chief of Statistics Canada’s Canadian Health Measures Survey (CHMS), responsible for the survey’s content team and Biobank. He is currently working to promote increased use of CHMS data and resources, including the valuable collection of Biobank specimens, by Canadian researchers in future health studies.
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