National Population Health Survey
General
The National Population Health Survey (NPHS) was designed to provide information related to the health of Canadians. Statistics Canada first conducted the NPHS in 1994 and continued every second year thereafter. The goal was to improve the information available to support the development and evaluation of health policies in Canada. The survey produces both cross-sectional information and longitudinal data in two-year intervals.
Methodology
The target population of the NPHS includes household residents from the 10 provinces, with the principal exclusion of populations on Indian reserves, Canadian Forces Bases and some remote areas in Quebec and Ontario. Separate surveys were conducted to cover the Yukon and Northwest Territories and institutions (long-term residents expected to stay longer than six months in health care institutions with four beds or more in all provinces). A representative sample of the Canadian population was obtained with household proportions based on 1991 Census data. The samples from each province were proportional to the province's 1991 Census population size.
Within each household, limited information on all members in the household was collected by proxy and this information made up the data found within the general component for all cycles. The health component consists of data gathered from an in-depth interview with a randomly selected member of the household (12 years and over for the 1994–1995 cycle and all ages for the subsequent cycles). The sample sizes from each cycle and each component are in Figure 1.
The large difference in the sample size for cycle 2 compared to the other two cycles is a result of large provincial buy-ins from Ontario, Alberta and Manitoba for 1996–1997.
The core content of the questionnaire includes information on health status (self-perception of health, functional ability, chronic conditions, activity restrictions); use of health services (visits to health care providers, hospital care and drug use); risk factors (smoking, alcohol use, physical activity); and demographic and socio-economic status (age, sex, education, ethnicity, household income, labour force status).
All cycles contain the same core content; however, the focus content differs from cycle to cycle, with 1994–1995 focus content investigating psycho-social health, and 1996–1997 focusing on access to health services.
Data Collection
Data from all cycles of the NPHS were collected through a combination of in-person interviews as well as telephone interviews (the percentage of each method varied for each cycle). The cross-sectional component of the survey, 1994–1995 and 1998–1999 cycles, selected a total of 27,263 and 19,973 households respectively, with corresponding overall household response rates of 89% and 88%. The 1996–1997 cycle differed from the other two cycles in that it allowed buy-in samples in Alberta, Manitoba and Ontario. For the 1996–1997 cycle, there was a total household sample of 95,370, with a household response rate of 83%.