BreastCheck Programme Statistics 2000-2001
The figures reported relate to those women contacted and/or screened by BreastCheck, the National Breast Screening Programme, from its commencement in February 2000 to the end of 2001.
Rigorous audit and Quality Assurance is an integral part of the screening process to ensure that women invited for screening receive the best quality service possible.
Throughout these statistics, the performance of BreastCheck is compared with predetermined standards based on European Guidelines for Quality Assurance in Mammography Screening (3rd Edition).
Overall, the statistics portray a picture of a breast screening programme that is performing to a very high standard in its initial 22 month period. For most performance parameters, the relevant standards are achieved or surpassed.
The Following Statistics' tables are available:
- Screening Activity by Age Group
- Screening Acceptance by Invitation
- Screening Outcome by Age Group
- Cancers with Non-operative Diagnosis
- Lymph Node Status
- Prevalent Screen by Region
- Women’s Charter Parameters
Screening Activity
Under a statutory amendment to the Data Protection Act, all women must give their consent for their data to be used. Consent letters are sent to identified women normally 10-12 weeks prior to an anticipated appointment. Any woman who receives a consent letter and does not wish to take part in the programme can notify BreastCheck in writing within 28 days. She is then termed as deconsented. If at any time a woman who has deconsented wants to be re-included in the programme she can do so by contacting BreastCheck.
The population register is formed using data from the following sources: Voluntary Health Insurance (VHI), General Medical Services (GMS) and Department of Social and Family Affairs. The Health (Provision of Information) Act, 1997 facilitated the compilation of these data. In addition women aged 50-64 years whose details are not held by any of the above can self-register with the programme. A freefone information line facilitates self-registration (1800 45 45 55). Data from BUPA Ireland is also being added to the population register.
The letter of invitation is issued to those women who do not initially deconsent. A change of appointment is possible. Women who fail to attend their screening appointment are issued with one further invitation.
Women may also be excluded or suspended from the programme following invitation, i.e. be ineligible, for a number of reasons, including previous bilateral mastectomy, a mammogram within 12 months, terminal illness, death and migration.
| Performance Parameter | 2000-2001 |
| Number of women sent consent forms | 64,766 |
| Number of women who deconsented following receipt of consent form | 1,193 |
| Number of women invited | 63,573 |
| Number of eligible women invited | 60,881 |
| Number of women attending for screening | 45,321 |
| Overall acceptance rate | 73% |
The acceptance rate is based on the numbers attending as a percentage of both the women who initially deconsented to involvement in the programme plus the number of eligible women invited for screening in the period. The acceptance rate for the programme was in excess of the acceptable international standard of 70%.
Screening Quality
Following mammographic screening, a woman is either informed that her mammogram is normal and that she will be recalled in two years (provided she remains within the specified age range of 50-64 years at that time) or is recalled for further assessment if an abnormality is detected. Best international practice requires that the assessment of screen-detected abnormalities is carried out by a skilled multi-disciplinary team consisting of Radiologists, Surgeons and Pathologists. Currently, further assessment is offered at either the Merrion or Eccles Unit. The rate of recall for assessment at 4.4% is within the target set of ≤ 10%.
The overall cancer detection rate achieved by the programme (9.1 per 1,000 women screened) exceeds the target for the prevalent round (the first round of screening) of >7 per 1,000 women screened. Cancers diagnosed are classified as invasive or ductal carcinoma in situ (DCIS). DCIS is a breast abnormality in which cancer cells are found contained within the walls of ducts in the breast tissue, but have not started to invade the rest of the breast or tissues beyond. The rate of detection of invasive breast cancer exceeds the target set, while the rate of detection of DCIS is within the target parameters.
The number of women with invasive cancers less than 15mm as a percentage of all women with invasive cancer exceeds the standard of 40%. The smaller the size of the tumour at diagnosis, the better the likely outcome will be. A small number of benign open biopsies were performed.
The Standardised Detection Ratio (SDR) is an age-standardised measure in which the observed number of invasive breast cancers detected is compared with the number which would have been expected if the age-specific detection rates achieved by the Swedish Two-County Randomised Controlled Trial applied (1). The SDR adjusts the observed cancer detection rates according to the age structure of the screened population. An SDR of 1.0 would indicate parity with the Two-County Study, where a large reduction in mortality was achieved.
The SDR calculated for the programme to date is corrected for the estimated percentage of women screened who have had mammography in the five years pre-screening (based on sampling). This corrected SDR is estimated to lie between 0.95 and 1.01. The crude, uncorrected SDR (0.89) would be an underestimate of the programme performance. The SDR achieved by the programme to date is above the acceptable standard of >0.75 and is close to or exceeds the target of >1.0; this indicates an excellent performance in this initial phase of screening.
| Performance Parameter | 2000-2001 | Standard |
| Number of women screened | 45,321 | - |
| Number of women recalled for assessment | 1,987 | - |
| % of women recalled for assessment | 4.4% | ≤10% |
| Number of benign open biopsies | 106 | - |
| Benign open biopsy rate per 1,000 women screened | 2.3 | <3.5 |
| Number of women diagnosed with cancer | 410 | - |
| Cancer detection rate per 1,000 women screened | 9.1 | >7 |
| Number of women with in situ cancer (DCIS) | 82 | - |
| Pure DCIS detection rate per 1,000 women screened | 1.8 | - |
| Number of women diagnosed with DCIS as % of all women diagnosed with cancer | 20% | 10-20% |
| Number of women diagnosed with invasive cancer | 328 | - |
| Invasive cancer detection rate per 1,000 women screened | 7.3 | >5.6 |
| Number of women with invasive cancers <15mm | 154 | - |
| Number of women with invasive cancers <15mm as % of all women with invasive cancers | 47% | ≥40% |
| Standardised detection ratio: corrected (crude) |
0.95-1.01 (0.89) |
>0.75 |
Screening Activity by Age Group
The acceptance rate was above the target of 70% in the age group 50-64; the rate was highest in the 50-54 year age group. The initial deconsent rate was highest in the older age groups. A small number of women under 50 were invited, largely those whose fiftieth birthday was in the year they were invited. A further small number of women were 65 by the time of invitation for screening. Data by age group is presented for the target age group of 50-64 only.
| - | 50-54 | 55-59 | 60-64 |
| Number of deconsented women | 189 | 349 | 435 |
| Number of eligible women invited | 15,486 | 22,525 | 17,797 |
| Numbers screened | 11,959 | 16,939 | 12,960 |
| Acceptance rate | 76.3% | 74.1% | 71.1% |
Screening Acceptance by Invitation
In all age groups the majority of those attending for screening responded to the first invitation to attend for mammography.
| - | 50-54 | 55-59 | 60-64 |
| Acceptance following one invitation only (%) | 67.6 | 65.0 | 63.0 |
| Acceptance following one invitation only (numbers) | 10,464 | 14,643 | 11,207 |
| Acceptance following second invitation (%) | 36.6 | 34.4 | 31.2 |
| Acceptance following second invitation (numbers)* | 1,495 | 2,296 | 1,753 |
| Total (numbers) | 11,959 | 16,939 | 12,960 |
* Some women declined to receive a second invitation at this time
Screening Outcome by Age Group
The percentage recalled for assessment in all age groups was well within the standard of ≤ 10%. The benign open biopsy rate was similarly low in all age groups. As expected, the cancer detection rate rose with increasing age.
| - | 50-54 | 55-59 | 60-64 |
| Number of women screened | 11,959 | 16,939 | 12,960 |
| % of women recalled for assessment | 4.9% | 4.2% | 4.0% |
| Benign open biopsy rate per 1,000 women screened | 2.9 | 2.8 | 1.4 |
| Overall cancer detection rate per 1,000 women screened | 7.3 | 8.2 | 9.9 |
Cancers with Non-operative Diagnosis
92% of women with breast cancer had their diagnosis made without an operation. This means that the woman can have a definite diagnosis made and consider the treatment options available to her before she undergoes any surgery or other therapy. This percentage exceeded the international standard.
| Performance Parameter | 2000-2001 | Standard |
| % of women with non-operative diagmosis of cancer | 92% | ≥ 70% |
Lymph Node Status
Almost all women with invasive cancer had a surgical procedure to document their nodal status. Knowledge of nodal status is important for treatment planning.
| Performance Parameter | 2000-2001 | Standard |
| Number of women with invasive cancer | 328 | - |
| % of women with invasive cancer where nodal status known | 98.5% | 100% |
Prevalent Screen by Region
Phase One of the National Breast Screening Programme involves the invitation of women resident in the Eastern Regional Health Authority, North Eastern and Midland Health Board areas. A number of women may have moved their area of residence to a location outside the target area of the programme in the time between receipt of initial consent and screening. These women remained part of the programme activity for the period reported (denoted as outside Phase One area).
The cancer detection rate was above the standard of >7/1,000 women screened among women resident in all three Health Board areas. The acceptance rate differed between Phase One areas but was above the standard of >70% among women resident in all.
| Region of Residence | Number of women screened | Acceptance rate | Number of women with cancer detected | Cancers detected per 1,000 women |
| Eastern Regional Health Authority | 33,042 | 72.3% | 307 | 9.3 |
| Midland Health Board | 4,802 | 71.6% | 42 | 8.8 |
| North-Eastern Health Board | 7,365 | 77.9% | 61 | 8.3 |
| Outside Phase One area | 112 | 67.1% | 0 | 0 |
| Total | 45,321 | 73% | 410 | 9.1 |
Women’s Charter Parameters
A National Breast Screening Programme Women's Charter was established at the initiation of the programme so that women are informed about what to expect from the screening process.
It is recognised that screening and assessment can cause anxiety to those women participating so every effort is made to minimise the time between invitation or recall and appointments.
| Performance Parameter | 2000-2001 | Women's Charter Standard |
| % of women who received seven days notice of appointment | 96.7% | ≥9o% |
| % of women who were sent results of mammogram within three weeks | 95.3% | ≥90% |
| % of women offered an appointment for Assessment Clinic within two weeks of notification of abnormal mammographic result | 90.5% | ≥90% |
| % of women given results from Assessment Clinic within one week | 89.1% | ≥90% |
| % of women offered hospital admission for treatment within three weeks of diagnosis of breast cancer.* | 84.8% | ≥90% |
* An additional small number of women had clinical investigations first or had primary treatment other than surgery
The National Breast Screening Programme achieved the standards set in many aspects of the Women's Charter. Although the percentage of women receiving results within one week of assessment clinic was slightly below the standard, the percentage receiving results within eight days was considerably higher at 93.8%.
Every effort is made to offer women admission to hospital, through agreements with the host hospitals, within three weeks of diagnosis and this was achieved in 84.8% of cases; 99.5% of women were offered hospital admission within six weeks of diagnosis.
Download Annual Report (.pdf file 208Kb, 24 pages - A4 format): bc_areport0102.pdf