Canadian Community Health Survey - Nutrition (CCHS)
Summary of changes
Activity on this program started: 2011
Target population - In 2004, the target population included persons under 1 year of age.
Instrument design - The length of the Health component is shorter than it was in 2004.
Sampling - The desired sample in 2004 (29,000) was much larger than in 2015 (24,000). In addition, the DRI age groups included ages < 1 and the male and female age groups for 19-50 were split into groups for 19-30 and 31-50.
Error detection - For 2015, limits were set for each standard food measurement unit on the size screen within in the CAI application. If an interviewer keyed a number outside of these limits, a prompt or "soft" edit would appear which asked the interviewer to confirm the amount. Limits were also specified for each of the up to ten food-specific units.
Estimation - With the availability of the Household Survey Frame, the multiple frame approach used in the 2004 CCHS - Nutrition was replaced with a single frame sample design in 2015. This change greatly simplified the sampling and weighting of the 2015 survey. In most cases, the Household Survey Frame provides household composition information, so the sample design could set sample size targets by Dietary Reference Intake Group, a key feature of the designs both in 2004 and 2015.
The overall sample size is smaller in 2015 than it was in 2004. Although the specific results depend on the domain of analysis and variable of interest, in general the smaller sample size will result in a higher sampling variance of a 2015 estimate compared to the equivalent 2004 estimate.
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 pilot survey for the Canadian Community Health Survey - Nutrition will test survey content, methodology, computer applications, interviewer procedures, reference material and data processing techniques in preparation for the main survey collection in 2015.
In recognition of a critical need for more extensive and recent information about the nutrition of Canadians, it was decided that Cycle 2.2 of CCHS would focus on nutrition. The primary goal of the Nutrition Survey is to provide reliable, timely information about dietary intake, nutritional well-being and their key determinants to inform and guide programs, policies and activities of federal and provincial governments and local health agencies.
The main objectives of the survey include:
- estimating the distribution of usual dietary intake in terms of foods, food groups, dietary supplements, nutrients and eating patterns among a representative sample of Canadians at national and provincial levels using a 24-hour dietary recall;
- gathering physical measurements for accurate body height and weight assessment;
- measuring the prevalence of household food insecurity;
- collecting data on selected health conditions and socio-economic and demographic characteristics of respondents.