Technical Information

Percentage of Ontario screen-eligible women with an abnormal OBSP screening mammogram result, 50-74 years old, who were diagnosed (benign or cancer) within the recommended time interval:

• ≤5 weeks without tissue biopsy, OR
• ≤7 weeks with tissue biopsy

Figures 2-5

While most women with an abnormal mammogram do not have breast cancer, additional assessment is required for definitive diagnosis. (1) 

Providing timely, well-coordinated follow-up with the appropriate interventions minimizes the fear and anxiety associated with abnormal results. (2-4)

1. Cancer Care Ontario. Ontario Breast Screening Program 2011 report. Toronto, Ontario: Cancer Care Ontario; 2013.
2. Canadian Partnership Against Cancer. Breast cancer screening in Canada: Monitoring and evaluation of quality indicators- results report, January 2011–December 2012. Toronto (ON): Canadian Partnership Against Cancer; 2017.
3. Canadian Partnership Against Cancer (2015). The 2015 cancer system performance report. Toronto: Canadian Partnership Against Cancer; 2015 June.
4. Canadian Partnership Against Cancer. Report from the evaluation indicators working group: Guidelines for monitoring breast cancer screening program performance (3rd edition). Toronto: Canadian Partnership Against Cancer; 2013 Feb.

(Total number of screen-eligible women with an abnormal OBSP screening mammogram result, 50-74 years old, who were diagnosed within the recommended time interval/ Total number of screen-eligible women, 50-74 years old, with an abnormal OBSP screening mammogram result) x 100 = Abnormal follow-up

N/A

Percentage (%)

•  ICMS (Integrated Client Management System) - OBSP mammograms and demographics, assessments

• OHIP CHDB (Claims History Database) - mastectomy claims

• OCR (Ontario Cancer Registry) - Invasive and in-situ breast cancers

• RPDB (Registered Persons Database) – Demographics

• PCCF+, version 6C - Residence and socio-demographic information 

2012-2015

• Provincial (Ontario)
• LHIN of residence

Total number of Ontario screen-eligible women, 50-74 years old, with an abnormal program screening mammogram result in a given calendar year

• Average risk women, aged 50-74 at the index date, who had an abnormal program mammogram result in Integrated Client Management System (ICMS)
• Index date was defined as the first OBSP screen date per person in ICMS in each calendar year
• Mammograms were identified by OBSP mammogram records in ICMS for screening purposes
• Women with abnormal program screening mammograms were identified as those referred for further testing by the screening radiologist in ICMS
• All mammograms in ICMS were counted, including those with partial views
• Each woman was counted once regardless of the number of mammograms performed
• LHIN assignment was determined using PCCF+, version 6C; residential postal code was used to identify LHIN

Exclusions:

• Women with a missing or invalid HIN, date of birth, postal code or LHIN
• Women with a prior diagnosis of invasive or in-situ breast cancer before the index date; prior diagnosis of breast cancer was defined as: ICD-O-3 codes: C50, a morphology indicative of breast invasive or in-situ cancer, microscopically confirmed with a path report
• Women with a mastectomy before the index date; mastectomy was defined in OHIP by fee codes E546, R108, R109, E505, E506 and R117

Women lost to follow-up or final diagnosis is unknown

Total number of Ontario screen-eligible women, 50-74 years old, with an abnormal program screening mammogram result in a given calendar year, who were diagnosed within the recommended time interval:

• Within five weeks of abnormal screen date if without a tissue (core or surgical) biopsy, OR
• Within seven weeks of abnormal screen date if with a tissue biopsy
• Date of diagnosis for benign cases was defined as (in order of preference):
  • Date of the last benign biopsy, or
  • Date of the last benign procedure, or
  • Date of the last procedure prior to a recommendation to return to regular screening
• Date of diagnosis for breast cancer cases was defined as:
  • Date of the first cytologic or pathologic diagnosis of breast cancer (in-situ or invasive)

For cases that were diagnosed as ductal carcinoma in-situ (DCIS) breast cancer on core biopsy but as invasive breast carcinoma on surgical biopsy, the date of diagnosis was defined as the earlier date (date of the core biopsy).

This indicator does not include OHIP billings for women screened outside of the OBSP since the OHIP database does not contain information about the results of the screening test or the results of the follow-up diagnostic work-up and final definitive diagnosis

• This indicator includes OBSP mammograms only
• There is at least an eight-month reporting lag for this indicator as the regions have up to and including eight months to close off assessment cases and enter the information to the ICMS