Canadian Community Health Survey - Nutrition (CCHS)

Status:
Active
Frequency:
Occasional
Record number:
5049

The Canadian Community Health Survey - Nutrition is a national health survey that collects information from Canadians about their eating habits and use of vitamin and mineral supplements, as well as other health factors.

Detailed information for 2015

Data release - planned for fall of 2016

Description

This survey will give a detailed and up-to-date picture of not only what people are eating and what vitamins and minerals they take, but the impact this has on health and well-being. It will also evaluate changes in food consumption, nutrition and health since this survey was last done in 2004.

The objectives of the Canadian Community Health Survey - Nutrition are:

(1) To collect detailed data on the consumption of foods and dietary supplements among a representative sample of Canadians at national and provincial levels;

(2) To estimate the distribution of usual dietary intake in terms of nutrients from foods, food groups, dietary supplements and eating patterns;

(3) To gather anthropometric (physical) measurements for accurate body weight and height assessment to interpret dietary intake;

(4) To support the interpretation and analysis of dietary intake data by collecting data on selected health conditions and socio-economic and demographic characteristics; and

(5) To evaluate changes in dietary intake from the 2004 CCHS - Nutrition.

The data collected from the survey will be used by Statistics Canada, Health Canada and the Public Health Agency of Canada, provincial and territorial ministries of health, as well as federal and provincial health planners across the country, industry and researchers and health professionals. Results from our surveys are used extensively for policy-making and program development that affect Canadian communities. The Canadian Community Health Survey has already been instrumental in drawing attention to emerging health issues, such as increasing trends in obesity.

Subjects

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

Data sources and methodology

Target population

The target population covers the population 1 year of age and over living in the ten provinces. Excluded from the survey's coverage are: persons living on reserves and other Aboriginal settlements, full-time members of the Canadian Forces and the institutionalized population.

Instrument design

The Canadian Community Health Survey - Nutrition questionnaire was developed by Statistics Canada in collaboration with stakeholders from Health Canada and the Public Health Agency of Canada, the Provincial Health Ministries, and an expert advisory group consisting of specialists from Health Canada, the Public Health Agency of Canada and academic experts. Content was chosen using the following set of criteria:

- Comparability with previous cycle of CCHS Nutrition survey
- Issues identified as priority for the support/development of programs and policy, surveillance requirements and/or research
- Significant number of people affected by the targeted issue
- Significant impact on family, community, and health care costs
- Data has potential for health improvement with policy intervention
- Issues identified as data gaps from the stakeholder consultations

Nutrition questions are designed for computer-assisted interviewing (CAI), meaning that, as the questions were developed, the associated logical flow into and out of the questions was programmed. This includes 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.

In collaboration with Statistics Canada's Questionnaire Design Resource Centre, the questionnaire was subjected to qualitative testing in May 2013, which consisted of one-on-one interviews. The objective was to evaluate respondent reactions to and understanding of the survey, as well as their willingness to respond to the questions. The qualitative testing was also used to obtain estimates for the various section times.

Sampling

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

Sample Size and Allocation

A sample of 24,000 respondents was desired at the national level. A minimum sample size in each province for each of twelve age-sex groups corresponding to Dietary Reference Intake (DRI) groups, was also targeted. These DRI groups are: ages 1-3, 4-8, 9-13 M, 9-13 F, 14-18 M, 14-18 F, 19-50 M, 19-50 F, 51-70 M, 51-70 F, 71+ M, and 71+ F.

A two-step strategy was used to allocate the sample to the provinces. First, 80 sample units were allocated to each DRI group in each province, accounting for 9600 units. The remaining 14,400 units were allocated to the provinces using a power allocation method with power q=0.7, based on the estimated population in each province. The total sample size of any given province was found by adding the sizes obtained in the two steps. The provincial sample was then allocated to the DRI groups based on a power allocation using q=0.5, to attain the targeted sample size in each DRI group in each province.

Sample sizes were enlarged to account for out-of-scope dwellings and anticipated non-response, for a total of 37,694 selected dwellings.

Sample Design

To select the sample of respondents for the 2015 CCHS - Nutrition Survey, a stratified three-stage design was used in each province except Prince Edward Island. In the first stage, geographical areas called clusters were selected. At the second stage, households were selected within each cluster, and in the third stage a person was selected within the household. In Prince Edward Island, a two-stage design was used, where the households are selected in the first stage and persons in the second stage. For operational reasons, the island was still divided up into areas however each of these areas appears in the sample.

The frame was created using Census Dissemination Areas (DAs) as building blocks for clusters. Neighbouring DAs were combined in such a way as to ensure as much as possible that clusters contain a minimum of 200 dwellings and not span too large a land area. Information from the Labour Force Survey (LFS) frame was used to identify areas of exclusion and remote areas, as well as to aid in decision-making when clusters did have a large land area.

In all provinces except PEI, clusters were selected by province with systematic probability proportional to size sampling. In PEI, no sampling of clusters was done (every cluster appears with certainty). To ensure that seasonality was taken into account, the selected clusters were allocated to collection periods to ensure an even distribution of sample and an even distribution of urban and rural clusters throughout the year. Households were then selected in each cluster. Upon visiting a selected dwelling, a roster of members in the household was created and a person was randomly selected among eligible members. The probability of selection of persons varied in order to attain the targeted sample sizes in each domain. Finally, each respondent was given a probability of selection for a 2nd dietary recall, which also varied according to the respondent's DRI group.

Data sources

Data collection for this reference period: 2015-01-02 to 2015-12-31

Responding to this survey is voluntary.

Data are collected directly from survey respondents.

Before the start of each collection period, introductory letters and brochures explaining the purpose of the survey are sent to the sampled households.

Respondents are interviewed using a computer assisted personal interview (CAPI). Approximately 30% of respondents will do a second dietary recall using a computer assisted telephone interview (CATI).

The format of the interview will be determined by the age of the selected respondent:

- Selected respondent ages 1 to 5: Proxy only (The parent or guardian is asked to provide the child's information.)

- Selected respondent ages 6 to 11: Parent-assisted (The child is asked to provide his/her information with the help of his/her parent or guardian.)

- Selected respondent ages 12 and up: Non-proxy (The respondent is asked to provide his/her own information.)

It should be noted that proxy interviews for respondents aged 6 and older are to occur only if the mental or physical health of the selected member makes it impossible to complete the interview during the collection period.

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.