Why another indicators project?

The Core Indicators for Public Health in Ontario started in 1998 when there weren’t quite so many indicator projects around. Nevertheless, this project is unique because it is Ontario-specific, detailed, and focused on the Ontario Public Health Standards. The website provides information and resources to help epidemiologists, analysts and planners generate indicators that are consistent across Ontario. It does not provide the data.


Are the Core Indicators "mandatory" for Ontario public health units?

The Core Indicators were developed with the intention that public health units and other organizations in Ontario adopt the indicators, apply the methods, and use the recommended data sources for the sake of consistency. Consistency is particularly important for indicators that correspond with objectives from the Ontario Public Health Standards. However, the Core Indicators are not "mandatory" or binding. Sometimes there are valid reasons for deviating from the recommendations; regardless, sufficient documentation is needed for readers to understand what methods were used in any analysis and to be able to replicate results if necessary. The data citations developed by the work group can help with this documentation.

Public health units are also encouraged to choose additional indicators for their health status reports to provide a complete picture of the community’s health and meet the needs of their area.


Where’s the data?

The Core Indicators provides definitions, methods and resources for calculating the indicators. Actual data are not presented. It is hoped that public health units and others will adopt the indicators as defined and generate them for their areas. The Health Indicators produced by Statistics Canada and the Canadian Institute for Health Information provide data for health regions in Canada. Each Core Indicator describes whether there is a corresponding national Health Indicator, highlights any definition differences, and provides a link to the appropriate page in the Statistics Canada website.


How do I cite the Core Indicators?

Since each indicator and resource is dated, cite the specific document, for example:

Core Indicators Work Group. Core Indicators for Public Health in Ontario: All-cause mortality indicator, September 25, 2002. URL: https://www.apheo.ca

Core Health Indicators Work Group. Core Indicators for Public Health in Ontario: Geography in Ontario, September 25, 2002. URL: https://www.apheo.ca


How were the Core Indicators selected?

The work group built the Core Indicators on the work of the past, most notably the Ontario Ministry of Health’s Community Health Profile produced in 1994, and the Central East Collaboration Project. The Collaboration Project started as a Metropolitan Toronto initiative. It brought together public health units and district health councils in Central East Region to design a chart book of health indicators. The indicators were produced by the Central East Health Information Partnership (CEHIP). Other HIUs had similar projects.

These projects formed the basis of work group’s work. The goal was to build on these foundations with special emphasis on defining indicators for objectives from the 1997 Mandatory Health Programs and Services Guidelines (MPSG) and updating them to the current Ontario Public Health Standards (OPHS).

Although one of the main reasons for including an indicator was that it applied to an objective of the MPSG or OPHS, other criteria were also considered. The indicator had to be useful and meaningful, and relevant to health. Applicable data had to be generally available at the public health unit level and the data had to be accessible. The indicator did not necessarily have to be available in all health units. As well, a few supplemental indicators were developed based on data from the Rapid Risk Factor Surveillance System (RRFSS), which is not available in all health units but may be the only source of data for some important indicators.

The indicators defined by the work group represent "core" indicators that are important to public health; however, the report goes beyond the OPHS, pushing the limits of what public health has traditionally done at the local level. Indicators for mental health and health expectancy are included to provide a well-rounded picture of the community.


Why do I need to standardize rates? Why use the crude rate?

To best understand mortality or disease trends in a population, it is important to determine crude rates, age-specific rates and age-standardized rates (SRATES) or ratios (SMRs, SIRs). The crude death (or disease) rate is the number of deaths (or disease cases) divided by the number of people in the population. This rate depicts the "true" picture of death /disease in a community although it is greatly influenced by the age structure of the population. An older population would likely have a higher crude death rate whereas a younger population may have a higher crude birth rate. Age-specific rates can best describe the "true" death /disease pattern of a community and allow comparison of populations that have different age structures.

Since many age-specific rates are cumbersome to present, age standardized rates have the advantage of providing a single summary number that allows different populations to be compared; however, they present an "artificial" picture of the death /disease pattern in a community. It is important to examine the data carefully before standardizing. In general, the SMR or SIR is used to compare an area (e.g., health unit) with one other area (e.g., Ontario). This indirect form of standardization requires a comparator that has a large population and stable age-specific rates. SRATEs, on the other hand, are generally used to compare a number of rates at the same time, e.g., health units across a region or rates over time. This direct form of standardization requires all comparators to have relatively stable age-specific rates. For more information about standardization, refer to the Resources section: Direct Standardization (SRATES) and Indirect Standardization (SMRs, SIRs) .


Why did the Core Indicators choose the 1991 Canadian population as the standard for calculating age-standardized rates?

The 1991 Canadian population was chosen for consistency with Statistics Canada and others. As well, this population is not vastly different from the populations of most Ontario health units.


What should I use as my denominator for calculating mortality and hospitalization rates?

For denominator data, use the most recent population estimates available which are distributed through Intellihealth by the Ontario Ministry of Health and Long Term Care. These estimates are available by age and sex for census sub-divisions (CSDs) and have been adjusted for net census undercoverage. See Population Estimates for more information.