Canadian Health Measures Survey (CHMS)

Status:
Active
Frequency:
Biennial
Record number:
5071

The Canadian Health Measures Survey (CHMS) aims to collect important health information through a household interview and direct physical measures at a mobile examination centre (MEC), sometimes referred to as a mobile clinic.

Detailed information for January 2012 to December 2013 (Cycle 3)

Data release - The first data release for this cycle is expected in October 2014.

Description

The Canadian Health Measures Survey (CHMS), launched in 2007, is collecting key information relevant to the health of Canadians by means of direct physical measurements such as blood pressure, height, weight and physical fitness. In addition, the survey is collecting blood and urine samples to test for chronic and infectious diseases, nutrition and environment markers.

Through household interviews, the CHMS is gathering information related to nutrition, smoking habits, alcohol use, medical history, current health status, sexual behaviour, lifestyle and physical activity, the environment and housing characteristics, as well as demographic and socioeconomic variables.

All of this valuable information will create national baseline data on the extent of such major health concerns as obesity, hypertension, cardiovascular disease, exposure to infectious diseases, and exposure to environmental contaminants. In addition, the survey will provide clues about illness and the extent to which many diseases may be undiagnosed among Canadians. The CHMS will enable us to determine relationships between disease risk factors and health status, and to explore emerging public health issues.

CHMS data are representative of the population whether they are healthy or not and provide a better picture of the actual health of Canadians.
The following are some of the measures that the CHMS includes:

Physical measures
. Anthropometry (standing height, sitting height, weight, waist circumference, hip circumference)
. Cardiovascular health and musculoskeletal fitness (resting heart rate and blood pressure, hand grip strength)
. Physical activity (accelerometry)
. Lung health (spirometry)
. Hearing (audiometry, otoacoustic emissions, otoscopy, tympanometry)

Blood measures
. Nutritional status (e.g., folate, Vitamin D)
. Diabetes (e.g., glycated hemoglobin A1c)
. Cardiovascular health (e.g., lipid profile, red blood cell fatty acids)
. Environmental exposure (e.g., acrylamides, dioxins, furans)
. Infection markers (e.g., hepatitis)

Urine measures
. Kidney health (e.g., creatinine)
. Environmental exposure (e.g., cotinine, pesticides)
. Nutritional status (e.g., iodine, Vitamin C)

Indoor air measures (household)
. Environmental exposure (volatile organic compounds)

Tap water (household)
. Environmental exposure (fluoride, volatile organic compounds)

The CHMS stores biological samples for further analyses of measures at a later date (Biobank). The CHMS team works closely with the Health Canada and Public Health Agency of Canada Research Ethics Board and the Office of the Privacy Commissioner of Canada in order to address privacy issues and to implement proper laboratory procedures.

Reference period:
Varies according to the question (for example: "over the last 12 months," "over the last 6 months," "during the last week")

Subjects

  • Diseases and health conditions
  • Environmental factors
  • Health
  • Lifestyle and social conditions

Data sources and methodology

Target population

The CHMS covers the population 3 to 79 years of age living in the ten provinces. Excluded from the survey's coverage are: persons living in the three territories; persons living on reserves and other Aboriginal settlements in the provinces; full-time members of the Canadian Forces; the institutionalized population and residents of certain remote regions. Altogether these exclusions represent less than 4% of the target population.

Instrument design

Household Questionnaire Design

The CHMS household questionnaire was conceived in collaboration with specialists from Statistics Canada, Health Canada, the Public Health Agency of Canada and specialists in medical and academic fields. The CHMS questions were designed for computer-assisted personal interviewing (CAPI), meaning that, as the questions were developed, the associated logical flow into and out of the questions was programmed. This included specifying the type of answer required, the minimum and maximum values, on-line edits associated with the question and what to do in case of item non-response.

Each question had to relate to a physical measure. Experts thoroughly reviewed the questionnaire many times during development. They provided valuable feedback on the questions and on the related physical measures.

The CHMS questionnaire and collection application were qualitatively tested to ensure respondent understanding of the questions and to identify any errors.

Sampling

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

The sample is allocated over 11 age-gender groups, with between 500 to 600 units per group (5,700 total) required to produce national estimates.

Since reporting units have to get to a mobile examination centre (MEC) located near their home for the physical measurements, site areas were limited to a radius of about 50 km (or up to 75 km for rural areas). To achieve this, collection sites were created using the Census geography. The geographic units used to define the sites were also grouped with respect to provincial boundaries, census metropolitan-area boundaries, health regions and population density criteria.

Using this frame, 360 sites were created. The sites were stratified based on the five regions of Canada: Atlantic, Quebec, Ontario, Prairies and British Columbia . It was decided that a sample of 16 collection sites was required. The sites were allocated by region: Atlantic (2), Quebec (4), Ontario (6), Prairies (2) and British Columbia (2).

Within each region, sites were sorted according to the size of their population and whether or not they belonged to a census metropolitan area. Within the Prairies and Atlantic regions, they were first sorted by province. Sites were randomly selected using a systematic sampling method with probability proportional to the size of each site's population.

Approximately 350 reporting units per site will participate in all parts of the survey, for a total of 5,700 across all sites.

Within each of the 16 selected sites, the list of the Census 2011 dwellings are used as a frame. New dwellings from Statistics Canada's address register are also used to improve the frame coverage.

Using the date of birth of household members present at Census time, as well as more current information from other administrative sources, dwellings are stratified according to six age groups. The sample is allocated in each stratum in such a manner as to obtain the target number of respondents by age group.

Selected dwellings are asked for the household member list at the time of the survey and one or two persons per household are selected to participate in the survey. The selection of persons is done randomly using a vector with variable selection probabilities by age group and sex.

Data sources

Data collection for this reference period: 2012-01-09 to 2013-12-17

Responding to this survey is voluntary.

Data are collected directly from survey respondents.

Collection includes a combination of a personal interview using a computer-assisted interviewing method and, for the physical measures, a visit to a mobile examination centre (MEC) specifically designed for the survey.

The CHMS will collect data in 16 sites across the country. The collection sites are located in six provinces: Nova Scotia, New Brunswick, Quebec, Ontario, Alberta and British Columbia. Collection is scheduled so that each region is distributed within the two-year collection period, distributed between seasons and in a way that tries to minimize the movement of staff and equipment between sites. The CHMS MEC stays in each site for five to seven weeks, collecting direct measures from approximately 350 respondents per site.

First step: personal interview at the household

The first contact with respondents is a letter sent through the mail. The letter informs people living at the sampled address that an interviewer will visit their home to collect some information about the household.

At the home, the application randomly selects one or two respondents and the interviewer conducts a separate health interview with each of them. The interview takes 45 to 60 minutes per respondent. The interviewer then assists the respondent in setting an appointment for the physical measures at the CHMS MEC.

Also, for a subsample of households, interviewers take a small sample of tap water to measure the level of fluoride and/or the level of 10 different volatile organic compounds.
Second step: visit to the CHMS MEC

Statistics Canada uses MECs to conduct the physical measures portion of the survey. Similar MECs have been used successfully for years by the NHANES in the United States.

The MEC consists of two trailers linked by an enclosed pedestrian walkway. One trailer serves as a reception and administration area, while the other contains physical measure rooms and a laboratory.

For each respondent, the complete visit to the MEC lasts about two hours. This is an approximate time, given that each respondent is assessed for their suitability for each measure and tested accordingly.

For children under 14 years of age, a parent or legal guardian has to be present with the child at the MEC and has to provide written consent for the child to participate in the tests.

At the end of their visit to the MEC, respondents are provided with a waterproof activity monitor. This small device is worn for a week at all times except when sleeping - even when swimming or bathing. It records information about normal physical activity patterns without the respondents having to do anything special.

Respondents are also asked to place an indoor air sampler, a small cylindrical device, in their home for the week following their visit to the MEC. The sampler measures a number of airborne substances in order to establish national baselines for indoor air concentrations of over 80 different volatile organic compounds.

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

Disclosure control

Statistics Canada is prohibited by law from releasing any information it collects which 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.

Documentation