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4A Chronic health problems prevalence

Description | Specific Indicators |  Ontario Public Health Standards (OPHS) | Corresponding Health Indicators from Statistics Canada and CIHI Data Sources |  Survey Questions  | Alternative Data Sources |  Analysis Check List | Method of Calculation |  Basic Categories | Indicator Comments | Cross-References to Other Indicators | Cited References |  Other References  |  Changes Made   Acknowledgements


  • Proportion of the population, aged 12 and older, that reported having been diagnosed with selected chronic health problems

Specific Indicators

  • Prevalence of asthma
  • Prevalence of high blood pressure
  • Prevalence of diabetes
  • Prevalence of heart disease
  • Prevalence of the effects of stroke

Ontario Public Health Standards (OPHS)

  • The Ontario Public Health Standards (OPHS) establish requirements for the fundamental public health programs and services carried out by boards of health, which include assessment and surveillance, health promotion and policy development, disease and injury prevention, and health protection. The OPHS consist of one Foundational Standard and 13 Program Standards that articulate broad societal goals that result from the activities undertaken by boards of health and many others, including community partners, non-governmental organizations, and governmental bodies. These results have been expressed in terms of two levels of outcomes: societal outcomes and board of health outcomes. Societal outcomes entail changes in health status, organizations, systems, norms, policies, environments, and practices and result from the work of many sectors of society, including boards of health, for the improvement of the overall health of the population. Board of health outcomes are the results of endeavours by boards of health and often focus on changes in awareness, knowledge, attitudes, skills, practices, environments, and policies. Boards of health are accountable for these outcomes. The standards also outline the requirements that boards of health must implement to achieve the stated results.

Outcomes Related to this Indicator

  • Societal Outcome (Chronic Disease Prevention): An increased proportion of the population lives, works, plays, and learns in healthy environments that contribute to chronic disease prevention. Chronic diseases of public health importance include cardiovascular diseases, cancer, respiratory diseases and type 2 diabetes.

Protocol Requirements Related to this Indicator

  • The board of health shall collect or access the following types of population health data and information: Morbidity, including...prevalence of chronic diseases (Population Health Assessment and Surveillance Protocol, 1b)

Corresponding Health Indicators from Statistics Canada and CIHI

  • Asthma
    Population aged 12 and over who report that they have been diagnosed by a health professional as having asthma.
  • High Blood Pressure
    Population aged 12 and over who report that they have been diagnosed by a health professional as having high blood pressure.
  • Diabetes
    Population aged 12 and over who report that they have been diagnosed by a health professional as having diabetes. Diabetes includes females 15 and over who reported that they have been diagnosed with gestational diabetes.

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Data Sources

Numerator & Denominator: Canadian Community Health Survey (CCHS)
Original source: Statistics Canada
Distributed by:
1. Ontario Ministry of Health and Long-Term Care (MOHLTC)
2. Statistics Canada
Suggested citation (see Data Citation Notes):
1. Canadian Community Health Survey [year], Statistics Canada, Share File, Ontario MOHLTC
2. Canadian Community Health Survey [year], Statistics Canada, Public Use Microdata File, Statistics Canada

Survey Questions 
The Canadian Community Health Survey (CCHS) has a core Chronic Conditions module that consists of a series of questions that ask about the chronic health problems the respondent may be living with. The respondent is asked about a variety of long-term problems that have been diagnosed by a health professional and which are expected to last 6 months or more.

Data Source



Response Categories




Chronic Conditions

Do you have asthma?

Don't Know,









Do you have high blood pressure?

Don't Know,









Do you have diabetes?

Don't Know,









Do you have heart disease?

Don't Know,









Do you suffer from the effects of a stroke?

Don't Know,









Alternative Data Sources
The Rapid Risk Factor Surveillance System (RRFSS) includes a core (seasonal) module on Chronic Diseases used to determine the prevalence of self-reported chronic diseases of public health importance (high blood pressure, asthma, and diabetes).  The question asks "Have you ever been told by a doctor or other health care professional that you have any of the following disorders?" Interviewer to read list to respondent (includes high blood pressure, asthma, diabetes and other chronic disease or disorder). 

Note that the age of respondents for the RRFSS starts at 18 years, as opposed to 12 years for the CCHS.

Analysis Check List


  • It is recommended that public health units use the Share File provided by the Ministry of Health and Long-Term Care rather than the public use file (PUMF) provided by Statistics Canada. The Share File has a slightly smaller sample size because respondents must agree to share their information with the province to be included; however, the share file has more variables and fewer grouped categories within variables. The Share File is a cleaner dataset for Ontario analysis because all variables that were not common content, theme content or optional content for Ontario have been removed.
  • There may be slight differences between results from the share file and data published on the Statistics Canada website for the Health Indicators because rates calculated for Health Indicators use the master CCHS data file.
  • Users need to consider whether or not to exclude the ‘Refusal, 'Don't Know' and ‘Not Stated' response categories in the denominator. Rates published in most reports, including Statistics Canada's publication Health Reports generally exclude these response categories. In removing not stated responses from the denominator, the assumption is that the missing values are random, and this is not always the case. This is particularly important when the proportion in these response categories is high.
  • Estimates must be appropriately weighted (generally the share weight for the CCHS) and rounded.
  • Users of the CCHS Ontario Share File must adhere to Statistics Canada's release guidelines for the CCHS data when publishing or releasing data derived from the file in any form. Refer to the appropriate user guide for guidelines for tabulation, analysis and release of data from the CCHS. In general, when calculating the CV from the share file using the bootstrap weights, users should not use or release weighted estimates when the unweighted cell count is below 10. For ratios or proportions, this rule should be applied to the numerator of the ratio.  Statistics Canada uses this approach for the tabular data on their website. When using only the Approximate Sampling Variability (CV) lookup tables for the share file, data may not be released when the unweighted cell count is below 30. This rule should be applied to the numerator for ratios or proportions.  This provides a margin of safety in terms of data quality, given the CV being utilized is only approximate.
  • Before releasing and/or publishing data, users should determine the CV of the rounded weighted estimate and follow the guidelines below:
    • Acceptable (CV of 0.0 - 16.5) Estimates can be considered for general unrestricted release. Requires no special notation. 
    • Marginal (CV of 16.6 - 33.3) Estimates can be considered for general unrestricted release but should be accompanied by a warning cautioning subsequent users of the high sampling variability associated with the estimates. Such estimates should be identified by the letter E (or in some other similar fashion).
    • Unacceptable (CV greater than 33.3) Statistics Canada recommends not to release estimates of unacceptable quality. However, if the user chooses to do so then estimates should be flagged with the letter F (or in some other fashion) and the following warning should accompany the estimates: "The user is advised that...(specify the data) not meet Statistics Canada's quality standards for this statistical program. Conclusions based on these data will be unreliable and most likely invalid". These data and any consequent findings should not be published. If the user chooses to publish these data or findings, then this disclaimer must be published with the data. 
  • Caution should be taken when comparing the results from Cycle 1.1 (2000/01) to subsequent years of the survey, due to a change in the mode of data collection.  The sample in Cycle 1.1 had a higher proportion of respondents interviewed in person, which affected the comparability of some key health indicators.  Please refer to for a full text copy of the Statistics Canada article entitled "Mode effects in the Canadian Community Health Survey: a Comparison of CAPI and CATI".


  • Users should refer to the most recent RRFSS Manual of Operations for a complete list of RRFSS analysis guidelines.
  • Denominator Data - cell size less than 30 not to be released (based on unweighted data).
  • Numerator Data - cell size less than 5 not to be released (based on unweighted data).
  • Coefficients of variation (CV) should be calculated for every estimate. The following categories determine the release of the data:
    • CV between 0 and 16.5: estimate can be released without qualification.
    • CV between 16.6 and 33.3: estimate can be released with qualification: interpret with caution. High variability.
    • CV greater than 33.3: estimate should not be released, regardless of the cell size.
  • 95% confidence intervals should accompany all released estimates. In general the simple computation of the C.I. for a proportion assuming SEp = sqrt(pq/n) and CI95% = p +/- 1.96*SEp is sufficient. However, if estimates are close to 0 or 100% and the simple computation confidence intervals include values less than zero or greater than 100 then the Fleiss 2nd edition computation for skewed estimates should be employed.
  • Weighting:
    • General household weight is to be applied. 
    • Household weights are not required to be recalculated for sub-population based questions; for example mammography in women ages 35+ years and 50-74 years.
    • If the weights supplied with the data set (health unit wave specific, health unit cumulative total, all health units combined wave specific, all health units combined cumulative total) are not appropriate for the required analysis, then a time-specific weight must be calculated. For example, a new weight is required for all seasonal modules.
  • If the cell size of ‘Don't Know' responses is 5% or greater, ‘Don't Know' responses should be included in the denominator of the analyses and reported separately.
  • If the cell size of ‘Refusal' responses is 5% or greater, ‘Refusal' responses should be included in the denominator of the analyses and reported separately.
  • When an indicator is being compared between groups (e.g. health units, time periods, sex), if any one group has ‘Don't Know' and/or ‘Refusal' responses that are 5% or greater, ‘Don't Know' and/or ‘Refusal' responses should be included in the denominator of the analyses and reported separately for all groups.
  • A provincial sample is not available with the RRFSS.
  • Refer to the RRFSS Data Dictionaries at for more information about module questions and indicators.

Method of Calculation


Weighted population aged 12+ reporting having the health problem

Weighted total population aged 12 +
 X 100,000

Basic Categories

  • Age groups for age-specific rates: 12-19, 20-44, 45-64, 65+
  • Sex: male, female
  • Geographic areas for: CCHS - all 36 Public Health Unit areas in Ontario; RRFSS - all participating Ontario Public Health Unit areas

Indicator Comments

  • The US Centers for Disease Control and Prevention defines chronic disease broadly as "illnesses that are prolonged, do not resolve spontaneously and are rarely cured completely."
  • Chronic diseases account for substantial burden of illness related to both morbidity and mortality. The leading causes of death in Canada are chronic diseases such as cardiovascular disease (CVD), cancer, respiratory diseases, diabetes and genitourinary diseases.1
  • Since this indicator is based on diagnosis by a physician, those with undiagnosed chronic health problems will likely be excluded and the true prevalence will be underestimated.1
  • The prevalence of chronic health problems varies considerably by age and sex.1
  • Risk factors for chronic diseases include, but are not limited to, poor diet, obesity, tobacco use, physical inactivity and alcohol use.
  • Substantial disparities in chronic disease risk factors exist when examined by age, sex, ethnicity and socioeconomic status (SES).
  • Obesity and overweight increases the risks associated with morbidity from various diseases and conditions, such as diabetes, coronary heart disease, stroke, and various forms of cancer.2
  • Studies have found that the prevalence of obesity isincreasing and, if remain unchanged, will have a profound impact on the prevalence of a wide variety of chronic diseases, and also on the health care system in terms of capacity issues and resource allocation.3-5
  • Research suggests that the increase in the prevalence of some risk factors will likely increase the prevalence of some chronic diseases beyond a shift in age distribution.1

Cross-References to Other Indicators

Cited References

  1. Haydon E, Roerecke M, Giesbrecht N, Rehm J, Kobus-Matthews M. Chronic disease in Ontario and Canada: Determinants, Risk Factors and Prevention Priorities.  Toronto: Ontario Chronic Disease Prevention Association, 2006.  Available from:
  2. Ahluwalia I, Mack K, Murphy W, Mokdad A, Bales V. State specific prevalence of selected chronic disease-related characteristics - behavioural risk fact surveillance system, 2001. Surveillance Summaries 2003; 52(8):1-80.
  3. Luo W, Morrison H, de Groh M, Waters C, DesMeules M, Jones-McLean E, Ugnat A, Desjardins S, Lim M, Mao Y. The burden of adult obesity in Canada. Chronic Diseases in Canada 2007; 27(4): 135-44.  Available from:
  4. MacDonald SM, Reeder BA, Chen Y. Canadian Heart Surveys Research Group. Obesity in Canada: a descriptive analysis. Canadian Medical Association Journal 1997; 157:s3-s9.
  5. Birmingham CL, Muller JL, Palepu A, Spinelli JJ, Anis AH. The cost of obesity in Canada. Canadian Medical Association Journal 1999; 160:483-8.

Other References

  • Badley EM, Glazier RH (Eds). Arthritis and related conditions in Ontario: ICES research atlas. 2nd ed. Toronto: Institute for Clinical Evaluative Sciences; 2004. Available from:
  • Health Canada. Respiratory Disease in Canada (Catalogue no. H39-593/2001E). Ottawa: Editorial Board. 2001. Available from:
  • Hux J, Booth G, Slaughter P, Laupacis A (Eds). Diabetes in Ontario: An ICES Practice Atlas. Toronto: Institute for Clinical Evaluative Sciences; 2003. Available from:
  • Tu JV, Ghali W, Pilote L, Brien S (Eds). CCORT Canadian Cardiovascular Atlas. Pulsus Group Inc and Institute for Clinical Evaluative Sciences; 2006. Available from:

Changes Made


Type of Review

(Formal or Adhoc)

Changes made by


March 12, 2009


Healthy Eating and Active Living subgroup

  • The description was changed from " Total number of people aged 12+ reporting having selected chronic health problems relative to the total population aged 12+" to "Proportion of the population, aged 12 and older, that reported having been diagnosed with selected chronic health problems".
  • The indicator was updated to reflect the new Ontario Public Health Standards.
  • Other changes were made to reflect the Guide to Creating and Editing Core Indicators.
 June 29, 2009 Ad hocHarleen Sahota on behalf of CIWG
  • Removed an out-of-date point in the Analysis Check List on how the Health Indicators department at Statistics Canada handles 'Not Stated' respondents when using CCHS data.



Lead Author

Shanna Hoetmer, York Region Community and Health Services

Krystina Nickerson, Ryerson University

Rebecca Truscott, Cancer Care Ontario

Wendy Young, Ryerson University

Contributing Author(s) 

Jennifer Skinner, Haliburton, Kawartha, Pine Ridge District Health Unit

Carol Paul, Ministry of Health and Long-Term Care

Jennifer Jenkins, Halton Region Health Department

Bethe Theis, Cancer Care Ontario

Art Salmon, Ministry of Health Promotion and Sport



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