The Ontario Health Survey 1996 - Data Sources

The 1996/97 OHS was conducted from October 1996 to August 1997 in conjunction with the National Population Health Survey (NPHS). The Ontario response rate to the NPHS was 78.8% of households (general survey) with 94.4% of selected individuals subsequently completing the health component. The 1996/97 OHS is comprised of 94.5% of these individuals aged 12+ who agreed to share their information with the province. The Ontario buy-in was conducted using computer-assisted telephone interviewing with sampling by random digit dialing. The buy-in supplemented the core NPHS sample. All health units were sampled and grouped into 23 health areas.

The 1996/97 OHS excluded certain groups such as the homeless, aboriginal people on reserves, and those living in institutions. Response rates varied by geographical area. Because of the complex sampling techniques, the 1996/97 OHS requires that sampling weights be used when tabulating data. Estimates with a coefficient of variation greater than 33.3% or based on cell sizes of less than 30 responses must be suppressed. This can be a common occurrence for some areas, particularly when the data are sub-divided by age and sex. Estimates with a CV between 16.6% and 33.3% should be noted as having high sampling variability. Depending upon the question, data may be subject to recall bias, social desirability bias and errors from proxy reporting. Few OHS questions are answered by proxy. The OHS is often the only source for certain types of health data; it covers the general population, and focuses on broad aspects of health, including lifestyle behaviours, health problems, and health care utilization.