The National Population Health Survey (NPHS) collects information related to the health of the Canadian population and related socio-demographic information.
Data release – March 22, 2004
In the fall of 1991, the National Health Information Council recommended that an ongoing national survey of population health be conducted. This recommendation was based on consideration of the economic and fiscal pressures on the health care systems and the commensurate requirement for information with which to improve the health status of the population in Canada. Commencing in April 1992, Statistics Canada received funding for development of a National Population Health Survey (NPHS).
The objectives of the NPHS are to:
- aid in the development of public policy by providing measures of the level, trend and distribution of the health status of the population;
- provide data for analytic studies that will assist in understanding the determinants of health;
- collect data on the economic, social, demographic, occupational and environmental correlates of health;
- increase the understanding of the relationship between health status and health care utilization, including alternative as well as traditional services;
- provide information on a panel of people who will be followed over time to reflect the dynamic process of health and illness;
- provide the provinces and territories and other clients with a health survey capacity that will permit supplementation of content or sample;
- allow the possibility of linking survey data to routinely collected administrative data such as vital statistics, environmental measures, community variables, and health services utilization.
The NPHS collects information related to the health of the Canadian population and related socio-demographic information. It is composed of three components: the Household, the Health Institutions, and the North components. Please note that the documentation for each of the NPHS components is presented separately.
The NPHS North component started in 1994-1995. Data for this component are obtained through a separate survey due to the special challenges of survey taking in Canada's North. Collection operations were carried out by the Statistical Bureaus in Yukon and Northwest Territories with funding provided by Statistics Canada. Data processing was performed by Statistics Canada. Most of the core content from the NPHS Household component was included in the North component questionnaire.
The North component was both cross-sectional and longitudinal in nature.
The target population of the Yukon/NWT NPHS survey included household residents living in private occupied dwellings located in the two territories, with the exclusion of populations on Indian Reserves, Canadian Forces Bases and in institutions. Moreover, persons living in unorganized areas in the Yukon (13% of the population) and persons living in unorganized areas, very small or extreme northern communities of the NWT (4.9% of the population) were also excluded from the target population.
In each selected household in the North, demographic information was collected from all household members, then one person, aged 12 years and over, was randomly selected for a more in-depth interview. The questionnaire included components on health status, use of health services, risk factors and demographic and socio-economic status.
This is a sample survey with a longitudinal design.
The sample design used for the Yukon/NWT household component of the NPHS was a stratified design with an independent sample selection process within each stratum. For the first two strata of the Yukon, the sample of households was selected through the use of a Random Digit Dialing (RDD) collection mode. RDD was implemented using the Elimination of Non-Working Banks Method, which gives rise to a simple random sample (without replacement) of residential telephone lines within each stratum. For the remaining three strata of the Yukon and for every stratum in the NWT, a simple random sample (without replacement) of dwellings was selected from a list frame of addresses in each community.
The NPHS longitudinal panel is comprised of persons. Up to this point, the sample design involved the selection of a household, which was the first stage of the sample design. Within each household selected for the NPHS component, one person was randomly chosen for the longitudinal panel. This represented the second stage of the sample design. Everyone in the household had an equal chance of being selected. With the use of random numbers printed on a label affixed to the questionnaire, the interviewer selected one person within the household and conducted the interview.
Responding to this survey is voluntary.
Data are collected directly from survey respondents.
Interviews were conducted by interviewers hired and trained by the Yukon and NWT Bureaus of Statistics. Households were contacted either in person or by phone, depending on their location. Typically, households in more urban areas were done by phone while rural and remote communities required visits.
In all dwellings, information about all household members was obtained from the person at home at the time of the interview. Such proxy interviewing of the household component is used to reduce cost.
Proxy reporting for the selected person was allowed only for reasons of illness or incapacity.
Interviewers hired translators in remote northern communities to try to reduce the number of non-interviews due to language problems.
Interviewers had several ways to trace a longitudinal respondent. The last known address and telephone number were provided as part of the information on the case, as well as the name and address of the previous contact, if collected. In addition, interviewers were trained to follow-up available leads such as local telephone directories and directory assistance. If these leads were unsuccessful, the case was transmitted to an experienced interviewer specially trained in tracing respondents. Tracer interviewers had access to Canada-wide directories and reverse directories.
In addition, movers to the South were traced by NPHS interviewers and interviewed using CAI. The data was processed through the Core processing system and then transferred to the North files
Data collected during the interview were captured in the offices of each Bureau. A capture system was designed by the NWT Bureau for use in each territory. The system was programmed to accept only valid response codes for each question and to follow the skip patterns of the questionnaire