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4B Cervical Cancer Screening

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


  • Proportion of women aged 20-69, excluding those having had a hysterectomy, who report having been screened for cervical cancer in the past three years.

Specific Indicators

  • Cervical cancer screening rate

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.

Link to OPHS 

Outcomes Related to this Indicator

  • Societal Outcome (Chronic Disease Prevention): There is increased adoption of behaviours and skills associated with reducing the risk of chronic diseases of public health importance.
  • Board of Health Outcome (Chronic Disease Prevention): The public is aware of the benefits of screening for early detection of cancers and other chronic diseases of public health importance.

Health Promotion and Policy Development Requirements Related to this Indicator

  • The board of health shall collaborate with community partners to promote provincially approved screening programs related to the early detection of cancers (Chronic Disease Prevention). 
  • The board of health shall increase public awareness in the following areas...benefits of screening for early detection of cancers and other chronic diseases of public health importance... These efforts shall include:
  • a. Adapting and/or supplementing national and provincial health communications strategies; and/or
    b. Developing and implementing regional/local communications strategies (Chronic Disease Prevention).
  • The board of health shall provide advice and information to link people to community programs and services on the following topics...Screening for chronic diseases and early detection of cancers (Chronic Disease Prevention).

Corresponding Health Indicator(s) from Statistics Canada and CIHI

• Pap (Papanicolaou) test : Women aged 18 to 69 who reported when they had their last Pap smear test.

Click on “Publications”Type in “Health Indicators” into the search boxScroll down and click on the html version of “Health Indicators” .
Click on “Data Tables and Maps” and then “Pap Smear” indicator.

Corresponding Indicator(s) from Other Sources

Ontario's Cancer System Quality Index1: Cervical cancer screening (With Pap Tests)

Search for "Cancer System Quality Index", then for "Access", then for "Cervical cancer screening".1

Data Sources

Numerator & Denominator: Canadian Community Health Survey (CCHS)
Original source: Statistics Canada
Distributed by:
1. Ontario 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 Pap Smear Test module was core in 2000/01, 2003 and 2005. It was optional content and selected by Ontario in 2007/08. These questions are asked of females who are 18 years and over. There is a Mammography module in the CCHS and this module was core content in 2000-01, 2003 and 2005. This module was optional content and selected by Ontario in 2007-08.

Data SourceModuleQuestionResponse CategoriesYearVariable
CCHSPap Smear Test moduleHave you ever had a Pap smear test?Yes,
Don't Know,
When was the last time? Less than 6 months ago,
6 months to less than 1 year ago,
1 year to less than 3 years ago,
3 years to less than 5 years ago,
5 or more years ago,
Don't Know,
Mammography module Have you had a hysterectomy? (uterus removed) Yes,
Don't Know,

Alternative Data Source(s)

Rapid Risk Factor Surveillance System (RRFSS) - Pap Smears module. This module was core in 2001 and 2002, optional from 2003-2005, rotating core in 2006 (i.e. core in 2006 and optional in 2007) and rotating core in 2008.

Data SourceModuleQuestionResponse CategoriesYearVariable
RRFSSPap Smears moduleHave you ever had a Pap smear test? Yes, No, Don't know, Refused 2001 - 2008 wh1
Did you have your last Pap smear test within the last two years?Yes, No, Don't know, Refused 2001 - 2005wh2
Can you tell me how many years ago you had your last Pap smear?2-70 enter exact number of years, Don't know, Refused 2001 - 2005 wh3
How long has it been since your last Pap smear test?Less than 12 months ago,
1 year but less than 2 years ago,
2 years but less than 3 years ago,
3 years but less than 4 years ago,
4 years but less than 5 years ago,
5 or more years ago,
Don't know, Refused
2006 - 2008wh2_new
Can you tell me how many years ago you had your last Pap smear?Greater than 2 years to less than 3 years ago greater than (24 months to less than 36 months ago),
3 years to less than 4 years ago (36 months to less than 48 months ago),
4 years to less than 5 years ago (48 months to less than 60 months ago),
5 or more years ago (60 months or more),
Don't know, Refused
2001 - 2005wh3_new  
For which one of the following three reasons did you have your last Pap test done: would you say it was for ONE, a regular check-up or routine visit; TWO, an ongoing or past problem, or THREE, a concern about a possible problem?Regular check-up/routine visit,
Ongoing/past problem,
Concern about a possible problem,
Don't know, Refused
2001 - 2008 wh4
Have you had a hysterectomy?Yes (includes partial hysterectomy),
No, Don't know, Refused
2001 - 2008wh5

Analysis Check List
  • Remove women who have had hysterectomies from the numerator and the denominator (see note in Indicator Comments below).


  • It is recommended that public health units use the Share File provided by the Ministry of Health and Long-Term Care rather than 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.
  • Not applicable respondents should be excluded; however, it is important to understand who these respondents are from the questionnaire skip patterns to be able to describe the relevant population.
  • 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 will be applied for questions related to the individual.
    • Household weight is to be applied for questions about households when we wish to determine the population/number of people affected.
    • Household weight is not to be applied for child proxy questions (bicycle helmet use, car seat safety), dog and cat immunization modules, or other questions that relate to the household rather than the respondent.
    • 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, gender), 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 number of women aged 20-69 who had a Pap test in the past 3 years who have not had a hysterectomy
Weighted number of women aged 20-69 who have not had a hysterectomy
 X 100

Basic Categories

  • Age groups: 20-44, 45-64, 65+, 20-69 (adult)
  • Geographic areas: CCHS- Public Health Unit; RRFFS- all participating health units; LHIN.

Indicator Comments

  • This indicator provides a measure for women aged 20-69 years of age. This age grouping is in alignment with the Ontario's Cancer System Quality Index1: Cervical cancer screening (With Pap Tests) indicator and with the January 2009 national report on monitoring cervical screening programs (page 9).2 Note that this is the age range recommended for screening program report indicators in light of the difficulty of estimating at a population level the proportion of women meeting cervical screening guidelines about time since first sexual activity. Note also that the population age indicator age range has been changed from 18-69 to 20-60.
  • Cervical cancer is completely treatable if detected early. Pap tests can also identify precancerous lesions, which can then be treated before they become invasive.
  • Screening is checking for a disease or condition when there are no symptoms. Diagnosis is identifying a disease or condition from its signs and symptoms. Some cancer detection tests may be performed for either screening or diagnostic reasons.
  • The Ontario Cervical Screening Collaborative Group recommends the following cervical screening guidelines (Revised June 2005; current as of January 2008): 3,4
    • All women who are, or ever have been, sexually active should be screened.
    • Cervical cytology screening should be initiated within three years of first vaginal sexual activity.
    • Screening should be done annually until there are three consecutive negative Pap tests.
    • After three annual negative Pap tests, screening should continue every two to three years. (These recommendations do not apply to women with previous abnormal Pap tests.)
    • Screening may be discontinued after the age of 70 if there is an adequate negative screening history in the previous 10 years (i.e., 3 or more negative tests).
  • The Analysis Check List recommends removing women who have had a hysterectomy. This is applicable when estimating recent proportions of women screened, or when estimating trends using CCHS data. Regional differences in hysterectomies would bias Pap test comparisons across regions or periods. See the ICES Atlas, p 188, hysterectomies mapped for early 1990s.5 CCHS does not collect information about whether hysterectomy was partial (subtotal) or complete. We don't know how women with subtotal hysterectomies answer the question, or what interviewers record if women say they had a partial hysterectomy. A woman who has had a subtotal hysterectomy still has a cervix and should still be having Pap tests. The ICES atlas also shows the trend to more subtotal hysterectomies, but "incidence" is still low, "prevalence" would be still lower, and so bias from inappropriately excluding women with subtotal hysterectomies should be minimal. Standard practice in the Public Health Agency of Canada's staff in Screening and Early Detection: Centre for Chronic Disease Prevention and Control, is to remove women who have had a hysterectomy from the sample before estimating cervical cancer screening rates (Lisa Pogany, personal communication, 30 January 2008).
  • Note that indicators directly addressing these recommendations are not easily obtained at a population level because frequency of screening depends upon a woman's past history of screens.
  • The data used for this indicator are self-reported. The screening rate may therefore be over or under-estimated. Self-report data may be subject to errors in recall, over or under-reporting due to social desirability, and errors from proxy reporting.

Cross-References to Other Indicators

  • Cancer Incidence (Section 4B: Cancer Incidence and Early Detection of Cancer)
  • Cancer Mortality (Section 4B: Cancer Incidence and Early Detection of Cancer)
  • Cited Reference(s)

    1. Cancer Care Ontario: Cancer System Quality Index: Cervical Cancer Screening (With Pap Tests), 2008.  Available online at: (Accessed February 10, 2009).
    2. Cervical Cancer Prevention & Control Network. Performance Monitoring for Cervical Cancer Screening Programs in Canada. Public Health Agency of Canada. January 2009. This report is to be posted at
    3. Ontario Cervical Screening Program. Ontario Cervical Screening Practice Guidelines. Revised June 2005. Available online: (Accessed February 10, 2009).
    4. C.M. McLachlin, V. Mai, J. Murphy, M. Fung Kee Fung, A. Chambers, and members of the Cervical Screening Guidelines Development Committee of the Ontario Cervical Screening Program and the Gynecology Cancer Disease Site Group of Cancer Care Ontario. Ontario Cervical Screening Evidence-Based Guidelines 2005 Full Report. Available online at: (Accessed February 10, 2009).
    5. Goel V, Williams J, Anderson G, Blackstien-Hirsch P, Fooks C, Naylor D. Patterns of Health Care in Ontario, 2nd edition. ICES. May 1996, Chapter 5, pp 116-124. Available online at: (Accessed February 10, 2009).

    Changes Made

    DateFormal Review or Ad Hoc?Changes made byChanges
    June 24 2009Formal Review Cancer, Smoking and Sun Safety subgroup of Core Indicators.

    ·   This indicator was updated in alignment with the Guide to Creating or Editing Core Indicators.
    ·   Changed age range to 20-69 from 18-69.
    ·   Changed "Method of Calculation" to specify restricting numerator and denominator to women who have not had a hysterectomy, indicated this in Analysis Checklist and added some discussion addressing this, as an Indicator Comment.
    ·   Added Cancer System Quality Index indicator under Corresponding Indicators from Other Sources.
    ·   Changed "Pap smear" to "Pap test".
    ·   Updated Ontario Cervical Screening Collaborative Group recommendations.
    ·   Updated Cited References

    June 29, 2009Ad 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.
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