Guidance

NHS Breast screening programme screening standards valid for data collected from 1 April 2021

Updated 27 September 2024

Applies to England

BSP-S01: uptake: timely invitation for screening – shadow

Description

The proportion of eligible women with a next test due date (NTDD) in the reporting period that are being invited for screening in the last 36 months of their previous invitation or screen. This standard is reported in 2 parts: S01a (women aged 53 to less than 71 years) and S01b (women aged 68 to less than 71 years).

This data is a one-off snapshot of the position at each breast screening office (BSO), taken on the first day of the month.

Rationale

To provide assurance that all eligible women are offered the opportunity for a breast screening appointment. S01a includes women aged 53 to less than 71 as all women are expected to have their first invite by the age of 53. In addition, women aged 68 to less than 71 years are reported separately in S01b to provide assurance that they have been sent their last invitation for routine screening.

Definition

S01a: women aged 53 to less than 71 years

Numerator: number of eligible women with a NTDD in the reporting period invited for screening less than or equal to 36 months as at the day of report.

An invitation is an episode with a date of first offered appointment within the review period.

Denominator: number of eligible women aged 53 to less than 71 years registered with a GP and with a NTDD in the reporting period, excluding women who have had a bilateral mastectomy.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S01b: women aged 68 to less than 71 years

Numerator: number of eligible women with a NTDD in the reporting period invited for screening less than or equal to 36 months as at the day of report.

An invitation is an episode with a date of first offered appointment within the review period.

Denominator: number of eligible women aged 68 to less than 71 years registered with a GP and with a NTDD in the reporting period, excluding women who have had a bilateral mastectomy.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

Acceptable level: to be set

Achievable level: to be set

Caveats

Although an invitation has been created it does not guarantee that it was printed, posted on the same day, or that the invitation letter was received.

Counts of women that have not been invited previously are not included.

The data extracted is as at the point of time and is taken from a live IT system.

Data collection and reporting

Data source: Breast Screening Select (BS Select). Data extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: NHS Digital.

Reported by: screening service and GP practice.

Published by: screening service.

Reporting period

Monthly.

Review dates

Date standard introduced: April 2021

Date standard last updated: April 2021

BSP-S02: coverage

Description

The proportion of eligible women who had a technically adequate screen at least once in the previous 36 months.

Rationale

To provide assurance that screening is offered to eligible women previously invited aged 53 to less than 71 years, and that each woman who chooses to accept screening has a technically adequate screen.

Definition

Numerator: number of eligible women with a technically adequate screen recorded less than or equal to 36 months.

A woman is counted as having a technically adequate screen (one which gives sufficient detail to allow a decision to be made to refer for assessment to return to a routine recall status) unless she was a technical recall or repeat and was lost to follow up.

Denominator: number of eligible women aged 53 to less than 71 years registered with a GP at 31 March in the reporting period, excluding women who have had a bilateral mastectomy.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

Acceptable level: greater than or equal to 70.0%

Achievable level: greater than or equal to 80.0%

Caveats

Screening services should have the outcomes of women recorded and finalised less than or equal to 6 months from their screening episode. If this is not done, it will adversely impact coverage.

Screening services may have large numbers of women populating screening batches (for example with confederated GP groups) which may mean that closing screening episodes within the required 6 month interval is difficult.

Some treatment regimens may expand beyond 6 months (for example where neo-adjuvant therapies are administered) which will mean for some women their episode will not be closed in less than or equal to 6 months.

If screening services have any screening slippage (all women not invited less than or equal to 36 months of their previous screen), it will adversely impact coverage. It will also invalidate many performance measures which are based on a 36-month screening interval.

Women registered with a GP but with no recorded address on Spine will be counted in the denominator but it will not be possible to invite them.

Data collection and reporting

Data source: Breast Screening Select (BS Select) (KC63 report). Data extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: NHS Digital.

Reported by: screening service, upper tier Local Authority of residence and GP practice.

Published by: upper tier local authority of residence.

Reporting period

Annually.

Review dates

Date standard introduced: April 2005

Date standard last updated: July 2019

BSP-S03: uptake

Description

The proportion of eligible women who have a technically adequate screen less than or equal to 6 months from date of first offered appointment. This standard is reported in 2 parts: S03a (routine screening) and S03b (very high risk screening).

Rationale

Maximising uptake increases the effectiveness of breast screening in helping to reduce deaths from breast cancer.

Definition

S03a: routine screening

Numerator: number of eligible women with a technically adequate screen less than or equal to 6 months from date of first offered appointment.

A woman is counted as having a technically adequate screen unless she was a technical recall or repeat and was lost to follow up.

Denominator: number of eligible women aged 50 to less than 71 years with a date of first offered appointment in the reporting period, excluding women who request an appointment after the initial episode is closed.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S03b: very high risk screening

Numerator: number of very high risk women with a technically adequate screen less than or equal to 6 months from the date of first offered appointment.

A woman is counted as having a technically adequate screen unless she was a technical recall or repeat and was lost to follow up.

Denominator: number of very high risk women aged less than or equal to 71 years with a date of first offered appointment in the reporting period, excluding women who request an appointment after the initial episode is closed.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

S03a: routine screening

Acceptable level: greater than or equal to 70.0%

Achievable level: greater than or equal to 80.0%

S03b: very high risk screening

Acceptable level: greater than or equal to 85.0%

Achievable level: greater than or equal to 95.0%

Caveats

Provisional quarterly data should be used with caution to measure performance as it will contain a proportion of women who were invited but have not yet attended the appointment. Data on this indicator will only be accurate 6 months after the end of the reporting period.

Data collection and reporting

Data source: national breast screening system (NBSS) (KC62 report). Quarterly data (provisional) extracted 4 weeks in arrears, annual data (definitive) extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Standard S03a is also the key performance indicator (KPI) BS1.

Reporting period

Quarterly (provisional data).

Annually (definitive data).

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2021

BSP-S04: uptake: screening round length

Description

The proportion of eligible women whose date of first offered appointment is less than or equal to 36 months from their previous episode (routine programme) or less than or equal to 12 months from their previous episode (very high risk programme).

This standard is reported in 2 parts: S04a (routine screening) and S04b (very high risk screening). S04b is a shadow standard for 2021/22.

Rationale

Provides assurance that women with a previous invitation for screening have a subsequent invitation in a timescale that maximises the chance of detection of cancer whilst minimising harm to them.

Definition

S04a: routine screening

Numerator: number of eligible women with date of first offered appointment less than or equal to 36 months from their previous episode. The previous episode refers to date of screening for women who attended or date of first offered appointment for women who did not attend.

Denominator: number of eligible women aged 50 to less than 71 years invited in the reporting period, excluding:

• self referrals

• GP referrals

• women offered screening for the first time

Women moving into a new breast screening office (BSO) will not be included in the numerator or denominator as the date of previous screen will not be available to calculate the screening round length. This is because a women’s screening history is not transferred when a woman moves BSO as each one has a separate instance of the screening database.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S04b: very high risk screening (shadow)

Numerator: number of very high risk women with date of first offered appointment less than or equal to 12 months from their previous episode. The previous episode refers to date of screening for women who attended or date of first offered appointment for women who did not attend.

Denominator: number of very high risk women aged less than 71 years invited in the reporting period, excluding:

• self referrals

• GP referrals

• women offered screening for the first time

• women requiring magnetic resonance imaging (MRI) surveillance only who do not respond to their initial communication letter

Women moving into a new BSO will not be included in the numerator or denominator as the date of previous screen will not be available to calculate the screening round length. This is because a women’s screening history is not transferred when a woman moves BSO as each one has a separate instance of the screening database.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

S04a: routine screening

Acceptable level: greater than or equal to 90.0%

Achievable level: greater than or equal to 99.0%

S04b: very high risk screening

Acceptable level: to be set

Achievable level: to be set

Caveats

None

Data collection and reporting

Data source: NBSS. Data extracted 4 weeks in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

This standard is also the KPI BS2.

Reporting period

S04a - Monthly and quarterly

S04b - Quarterly

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2021

BSP-S05: test: repeat mammography rate

Description

The proportion of women who had additional mammograms due to technical recalls or technical repeats. This standard is reported in 2 parts: S05a (technical recall) and S05b (technical repeat).

Rationale

Mammograms may need to be repeated if the quality of the first image is not adequate for diagnostic reporting. Services should aim to deliver the optimum image quality with as low a radiation dose as possible to minimise anxiety for women and their exposure to radiation. The number and type of repeat mammography are monitored to make sure good quality practice is provided. Further information is available in repeat mammogram guidance.

Definition

S05a: technical recall

Numerator: number of women screened requiring a further appointment for repeat images due to technical recall.

Denominator: number of women attending screening in the reporting period.

The recall decision is made at the time of reporting the images and will require the woman to be booked into another appointment and re-attend for screening.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S05b: technical repeat

Numerator: number of women screened requiring repeat images due to technical repeat.

Denominator: number of women attending screening in the reporting period.

The decision to repeat images is made at the time of the initial screening appointment and the woman is not required to re-attend for screening.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

S05a: technical recall

Acceptable level: less than 0.7%

Achievable level: less than 0.2%

S05b: technical repeat

Acceptable level: less than 2.0%

Achievable level: less than 1.2%

Caveats

This standard is calculated including trainee mammographers (radiographers and assistant practitioners). Repeat mammography rates may be higher for trainee mammographers than trained staff. Services should calculate performance both including and excluding trainees and by individual mammographer for internal monitoring.

Data collection and reporting

Data source: NBSS. Data extracted 4 weeks in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Monthly and quarterly.

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2021

BSP-S06: test: timeliness of screening results letters that do not require further assessment

Description

The proportion of women who have a results letter with no referral for further testing produced on NBSS less than or equal to 2 weeks from a technically adequate screen. This standard is reported in 2 parts: S06a (routine screening) and S06b (very high risk screening).

Rationale

To minimise anxiety it is essential that women receive screening results in a timely manner.

Definition

S06a: routine screening

Numerator: number of women with a technically adequate screen with no referral for further testing with a results letter produced on NBSS less than or equal to 2 weeks (less than or equal to 14 calendar days) from the screen date.

Date of the screen is day 0. For women who have a technical recall the standard is still measured from the date of their initial screen.

Denominator: number of women who had their first offered screening appointment in the reporting period with a technically adequate screen and did not require further tests at an assessment clinic.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S06b: very high risk screening

Numerator: number of very high risk women with a technically adequate screen with no referral for further testing with a results letter, produced on NBSS less than or equal to 2 weeks (less than or equal to 14 calendar days) from the screen date.

Date of the screen is day 0. Where more than one screening modality is used, the latest test date will be counted as the date of screen. For women who have a technical recall the standard is still measured from the date of their initial screen.

Denominator: number of very high risk women who had their first offered screening appointment in the reporting period with a technically adequate screen and did not require further tests at an assessment clinic.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

‘Produced’ relates to the letter being created on NBSS and does not guarantee that it was printed, posted on the same day or that the letter was received. The programme recommends that letters are printed and posted on the same day they are produced.

Performance thresholds

S06a: routine screening

Acceptable level: greater than or equal to 95.0%

Achievable level: greater than or equal to 99.0%

S06b: very high risk screening

Acceptable level: greater than or equal to 95.0%

Achievable level: greater than or equal to 99.0%

Caveats

None

Data collection and reporting

Data source: NBSS. Data extracted 4 weeks in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

S06a - Monthly and quarterly

S06b - Quarterly

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2021

BSP-S07: referral: rate of referral to assessment

Description

The proportion of eligible women with a technically adequate screen who are referred for assessment. This standard is reported in 3 parts: S07a (prevalent screen), S07b (incident screen) and S07c (very high risk screening).

Rationale

To provide assurance that women are not referred for further tests unnecessarily. Those responsible for interpreting the images from breast screening need to make sure that they are recalling women with areas of concern which require further investigation, whilst not recalling too many women where no abnormalities are subsequently found.

Definition

S07a: prevalent screen

Numerator: number of eligible women with a technically adequate prevalent screen referred for assessment.

Denominator: number of eligible women aged 45 to less than 53 years with a technically adequate prevalent screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S07b: incident screen

Numerator: number of eligible women with a technically adequate incident screen referred for assessment.

Denominator: number of eligible women aged 50 to less than 71 years with a technically adequate incident screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S07c: very high risk screening

Numerator: number of very high risk women with a technically adequate screen referred for assessment.

Denominator: number of very high risk women aged less than 71 years with a technically adequate screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

S07a: prevalent screen

Acceptable level: less than 9.0%

Achievable level: less than 7.0%

S07b: incident screen

Acceptable level: less than 4.0%

Achievable level: less than 3.0%

S07c: very high risk screening

Acceptable level: less than 10.0%

Achievable level: less than 7.0%

Caveats

This standard is calculated using all image readers. Rates of referral to assessment may be higher for new image readers on average than experienced readers. Services should review performance both including and excluding new image readers for internal monitoring.

Data collection and reporting

Data source: NBSS (KC62 report, Table A and Table C1). Quarterly data (provisional) extracted 6 weeks in arrears, annual data (definitive) extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Quarterly (provisional data).

Annually (definitive data).

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2021

BSP-S08: diagnosis and or intervention: short-term recall rates

Description

The proportion of women screened who are referred for further tests and invited back to assessment at an interval of at least one year (short-term recall).

Rationale

Every effort should be made to obtain a definitive diagnosis at initial assessment. Short-term recall should be used only in exceptional circumstances and with personal informed choice, as it is associated with significant anxiety. Women should not usually receive more than one short-term recall outcome within a normal 3-yearly screening episode.

Detailed information is available in the clinical guidance for breast cancer screening assessment and quality assurance guidelines for breast cancer screening radiology.

Definition

Numerator: number of eligible women with a technically adequate screen placed on short-term recall.

Denominator: number of eligible women aged 50 to less than 71 years with a technically adequate screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

Acceptable level: less than 0.25%

Achievable level: less than 0.12%

Caveats

None

Data collection and reporting

Data source: NBSS (KC62 report, Table T). Quarterly data (provisional) extracted 6 weeks in arrears, annual data (definitive) extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Quarterly (provisional data).

Annually (definitive data).

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2017

BSP-S09: referral: time to first offered appointment for assessment

Description

The proportion of women referred for assessment whose date of first offered appointment at an assessment centre is less than or equal to 3 weeks (less than or equal to 21 calendar days) from attendance for the screening mammogram. This standard is reported in 2 parts: S09a (routine screening) and S09b (very high risk screening).

Rationale

To minimise time taken for women who need further tests to obtain a definitive malignant, benign or normal diagnosis. It is useful to examine this standard in conjunction with the time from screening mammogram to actual attendance at assessment to make sure that actual waiting times are being minimised.

Definition

S09a: routine screening

Numerator: number of women whose date of first offered appointment for assessment is less than or equal to 3 weeks (less than or equal to 21 calendar days) from an initial technically adequate screen.

Date of the screen is day 0. For women who have a technical recall the standard is still measured from the date of their initial screen.

Cancellations to attend assessment by the woman do not impact on the first offered appointment date. Cancellations by the service to a later assessment date will extend the waiting time.

Denominator: number of women referred for assessment following an initial technically adequate screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S09b: very high risk screening

Numerator: number of very high risk women whose date of first offered appointment for assessment is less than or equal to 3 weeks (less than or equal to 21 calendar days) from an initial technically adequate screen

Date of the screen is day 0. Where more than one screening modality is used, the latest test date will be counted as the date of screen. For women who have a technical recall the standard is still measured from the date of their initial screen.

Cancellations to attend assessment by the woman do not impact on the first offered appointment date. Cancellations by the service to a later assessment date will extend the waiting time.

Denominator: number of very high risk women referred for assessment following an initial technically adequate screen in the reporting period

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

S09a: routine screening

Acceptable level: greater than or equal to 95.0%

Achievable level: greater than or equal to 99.0%

S09b: very high risk screening

Acceptable level: greater than or equal to 95.0%

Achievable level: greater than or equal to 99.0%

Caveats

None

Data collection and reporting

Data source: NBSS. Data extracted 6 weeks in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

S09a - monthly and quarterly

S09b - quarterly

Review dates

Date standard introduced: April 2017

Date standard last updated: April 2021

BSP-S10: diagnosis and or intervention: definitive diagnosis of cancer made less than or equal to 3 assessment visits

Description

The proportion of women diagnosed with breast cancer who have attended less than or equal to 3 appointments for assessment and results.

Rationale

It is important to reduce anxiety in women by minimising the number of assessment appointments required to obtain a definitive diagnosis. An early non-operative diagnosis of malignancy is better as it allows informed pre-treatment counselling for the woman and facilitates one-stage treatment so that anxiety is minimised.

Definition

Numerator: number of women diagnosed with breast cancer who have attended less than or equal to 3 appointments for assessment and results (assuming 1 results appointment).

Denominator: number of women diagnosed with breast cancer following screening in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

Acceptable level: greater than or equal to 95.0%

Caveats

In some circumstances, repeated appointments may be necessary where difficult to diagnose lesions are found to be multi-focal or the multi-disciplinary team (MDT) need to complete further investigations.

The number of appointments will depend on the organisation of assessment. However, no more than 2 needle biopsy procedures carried out on separate occasions should normally be needed to achieve a non-operative diagnosis. Some services may not have the resources to allow all investigations to be undertaken in one visit. This may lead to more than 2 appointments for further diagnostic tests.

Data collection and reporting

Data source: NBSS.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: sub-region.

Reporting period

Annually as part of the Association of Breast Surgery (ABS) audit.

Review dates

Date standard introduced: April 2005

Date standard last updated: April 2017

BSP-S11: diagnosis and or intervention: rates of benign open biopsies

Description

The rate of eligible women with a technically adequate screen who have an open surgical biopsy with a benign or normal histological outcome. This standard is reported in 2 parts: S11a (prevalent screen) and S11b (incident screen).

Rationale

To minimise harm to women due to unnecessary surgery. The number of open surgical biopsies performed because of screening that prove to be benign should be as low as possible.

Definition

S11a: prevalent screen

Numerator: number of eligible women who had an open surgical biopsy with a benign or normal histological outcome.

Denominator: number of eligible women aged 45 to less than 53 years with a technically adequate prevalent screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 1,000 to give a rate.

S11b: incident screen

Numerator: number of eligible women who had an open surgical biopsy with a benign or normal histological outcome.

Denominator: number of eligible women aged 50 to less than 71 years with a technically adequate incident screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 1,000 to give a rate.

Performance thresholds

S11a: prevalent screen

Acceptable level: less than 1.5 per 1,000

Achievable level: less than 1.0 per 1,000

S11b: incident screen

Acceptable level: less than 1.0 per 1,000

Achievable level: less than 0.75 per 1,000

Caveats

Lack of availability or access to vacuum assisted biopsy could impact on the number of women referred to open surgical biopsy. Further guidance is available in the guidance on recording vacuum-assisted excisions.

Data collection and reporting

Data source: NBSS (KC62 report, Table A and Table C1). Six-monthly data (provisional) extracted 2 months in arrears, annual data (definitive), extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Six-monthly (provisional data)

Annually (definitive data)

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2017

BSP-S12: diagnosis and or intervention: rates of non-operative diagnosis

Description

The proportion of women with a non-operative diagnosis of cancer by needle histology or cytology.

Rationale

It is important to minimise the number of operative procedures and to enable treatment planning in advance of surgery. To achieve this the majority of women should receive a non-operative pathological diagnosis of cancer.

Definition

S12a: invasive malignancy

Numerator: number of eligible women with a non-operative diagnosis of invasive breast cancer.

Denominator: number of eligible women aged 50 to less than 71 years diagnosed with invasive breast cancer in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S12b non-invasive carcinoma (including ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS)) and micro-invasive carcinoma (less than or equal to 1mm in size)

Numerator: number of eligible women with a non-operative diagnosis of in-situ breast cancer.

Denominator: number of eligible women aged 50 to less than 71 years diagnosed with in situ breast cancer or micro-invasive carcinoma in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

S12a: invasive malignancy

Acceptable level: greater than or equal to 99.0%

S12b: non-invasive carcinoma (including DCIS and LCIS) and micro-invasive carcinoma (less than or equal to 1mm in size)

Acceptable level: greater than or equal to 90.0%

Achievable level: greater than or equal to 95.0%

Caveats

Non-invasive carcinoma is calculated including LCIS. Non-operative diagnosis rates may be lower where there is a high proportion of LCIS because these are not reported as malignant prior to surgical confirmation. Services not reaching the acceptable threshold for non-invasive carcinoma should calculate the rate both with and without LCIS for internal monitoring.

Data collection and reporting

Data source: NBSS (KC62 report, Table T). Six-monthly data (provisional) extracted 2 months in arrears, annual data (definitive), extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Six-monthly (provisional data)

Annually (definitive data)

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2021

BSP-S13: referral: positive predictive value of referral

Description

The proportion of women referred for assessment with a final outcome of breast cancer (invasive and non-invasive disease). This standard is reported in 2 parts: S13a (prevalent screen) and S13b (incident screen).

Rationale

Positive predictive value of referral to assessment gives an indication of how effective the service is in identifying true cancers out of those referred with suspected cancer. Services should aim to maximise the number of cancers detected whilst minimising the number of women recalled to assessment.

Definition

S13a: prevalent screen

Numerator: number of eligible women with a diagnosis of breast cancer (invasive, micro-invasive and non-invasive disease).

Denominator: number of eligible women aged 45 to less than 53 years referred for assessment following an initial technically adequate prevalent screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

S13b: incident screen

Numerator: number of eligible women with a diagnosis of breast cancer (invasive, micro-invasive and non-invasive disease).

Denominator: number of eligible women aged 50 to less than 71 years referred for assessment following an initial technically adequate incident screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.

Performance thresholds

S13a: prevalent screen

Acceptable level: greater than or equal to 8.0%

Achievable level: greater than or equal to 12.0%

S13b: incident screen

Acceptable level: greater than or equal to 24.0%

Achievable level: greater than or equal to 33.0%

Caveats

Services with a small eligible population (inviting less than 20,000 women per year) should aggregate data over at least 3 years.

Data collection and reporting

Data source: NBSS (KC62 report, Table A and Table C1). Data extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Annually.

Review dates

Date standard introduced: April 2021

Date standard last updated: April 2021

BSP-S14: diagnosis and or intervention: age standardised detection ratios (SDRs) for invasive cancers

Description

The SDR is the ratio of the observed number of invasive cancers to the expected number in the eligible population invited and screened, given the age distribution of the population screened. This standard is reported in 2 parts: S14a (prevalent screen) and S14b (incident screen).

Rationale

Services should aim to maximise the numbers of invasive cancers detected. It is important to be able to compare cancer detection between screening services with differing mean ages of screening populations, as the age of women screened is a major determinant of cancer detection rates. This is adjusted for by using a SDR.

Definition

S14a: prevalent screen

Numerator: number of invasive cancers diagnosed in eligible women aged 45 to less than 71 years with a technically adequate prevalent screen in the reporting period.

Denominator: the expected number of invasive cancers in eligible women aged 45 to less than 71 years from the prevalent screen.

We calculate performance by dividing numerator by denominator.

The expected number of cancers is based on applying criteria from the Swedish Two Counties randomised control trial which is used as a comparator of performance. A 20% increase on the original expected levels has been used to account for the increase in background incidence of invasive breast cancer in the population since the previous rates were applied in 1993.

S14b: incident screen

Numerator: number of invasive cancers diagnosed in eligible women aged 50 to less than 71 years with a technically adequate incident screen in the reporting period.

Denominator: the expected number of invasive cancers in eligible women aged 50 to less than 71 years from the incident screen.

We calculate performance by dividing numerator by denominator.

The expected number of cancers is based on applying criteria from the Swedish Two Counties randomised control trial which is used as a comparator of performance. A 20% increase on the original expected levels has been used to account for the increase in background incidence in invasive breast cancer in the population since the previous rates were applied in 1993.

Performance thresholds

S14a: prevalent screen

Acceptable level: greater than or equal to 1.00

Achievable level: greater than or equal to 1.20

S14b: incident screen

Acceptable level: greater than or equal to 1.00

Achievable level: greater than or equal to 1.20

Caveats

Screening intervals shorter or longer than 36 months will have an impact on rates of cancer detection. Care should be taken when interpreting this standard. The ability of a screening service to maintain screening round length (BSP-S04) over the period should be analysed. Services with a small eligible population (inviting less than 20,000 women per year) should aggregate data over at least 3 years and add tables A1, B1 and C1 together.

Data collection and reporting

Data source: NBSS (KC62 report, Table A and B and Table C1). Six-monthly data (provisional) extracted 2 months in arrears, annual data (definitive) extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Six-monthly (provisional data).

Annually (definitive data).

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2021

BSP-S15: diagnosis and or intervention: small cancer age standardised detection ratios (SDRs) for invasive cancers

Description

The SDR is the ratio of the observed number of invasive cancers to the expected number in the eligible population invited and screened, given the age distribution of the population screened. Small cancers (less than 15mm in diameter) are expected to be 55% of the expected overall number of invasive cancers.

Rationale

To reduce breast cancer mortality it is important that small invasive breast cancers (less than 15 mm diameter) are detected. It is important to be able to compare cancer detection between screening services with differing mean ages of screening populations, as the age of women screened is a major determinant of cancer detection rates. This is adjusted for by using a SDR.

Definition

Numerator: number of invasive cancers measuring less than 15mm in diameter diagnosed in eligible women aged 45 to less than 71 years with a technically adequate screen in the reporting period.

Denominator: the expected number of invasive cancers measuring less than 15mm in diameter diagnosed in eligible women aged 45 to less than 71 years.

We calculate performance by dividing numerator by denominator.

The expected number of cancers is based on applying criteria from the Swedish Two Counties randomised control trial which is used as a comparator of performance. A 20% increase on the original expected levels has been used to account for the increase in background incidence in invasive breast cancer in the population since the previous rates were applied in 1993.

Performance threshold

Acceptable level: greater than or equal to 1.00

Achievable level: greater than or equal to 1.20

Caveats

The size distribution of all invasive cancers should be examined to establish whether there is any ‘rounding up’ of cancers measuring between 14mm and 15mm by pathologists. If this is shown, it may reduce the numbers of small cancers detected.

Services should use KC62 to identify the number of invasive cancers with an unknown size. The cases should be audited to assess whether any were less than 15mm diameter as these will not be included in the numerator.

Screening intervals shorter or longer than 36 months will have an impact on rates of cancer detection. Care should be taken when interpreting this standard. The ability of a screening service to maintain screening round length (BSP-S04) over the period should be analysed. Services with a small eligible population (inviting less than 20,000 women per year) should aggregate data over at least 3 years.

Data collection and reporting

Data source: NBSS (KC62 report, Tables A, B and Table C1). Six-monthly data (provisional) extracted 2 months in arrears, annual data (definitive) extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Six-monthly (provisional data).

Annually (definitive data).

Review dates

Date standard introduced: April 2017

Date standard last updated: April 2021

BSP-S16: diagnosis and or intervention: non-invasive cancer detection rates

Description

The rate of non-invasive carcinoma (in situ) cancers that are detected per 1,000 women screened. This standard is reported in 2 parts: S16a (prevalent screen) and S16b (incident screen).

Rationale

Detection of non-invasive cancer at screening (predominantly DCIS), particularly high-grade disease, is assumed to be a factor contributing to long-term reduction in mortality. No firm scientific evidence currently exists to confirm this. The majority of DCIS detected at screening is of the high-risk type. It is believed to be good practice to detect and treat DCIS.

Some experts have argued that detection of this stage of breast carcinoma may represent over diagnosis (detecting disease which would never become clinically apparent or threaten life) and causes anxiety and physical harm (unnecessary surgery). Others suggest that detection of DCIS is important because it is a precursor of invasive carcinoma.

Until there is definitive evidence, national screening programme advice is to maximise detection of non-invasive cancer (particularly high-grade disease). This definitive evidence is awaited from the Sloane Project and clinical trials of active monitoring for potentially low-risk DCIS, namely:

• the LORIS trial

• the LORD trial

Definition

S16a: prevalent screen

Numerator: number of women with non-invasive carcinoma (DCIS and LCIS) or micro-invasive cancer (less than or equal to 1mm in size).

Denominator: number of eligible women aged 45 to less than 71 years with a technically adequate prevalent screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 1,000 to give a rate.

S16b: incident screen

Numerator: number of women with non-invasive carcinoma (DCIS and LCIS) or micro-invasive cancer (less than or equal to 1mm in size).

Denominator: number of eligible women aged 50 to less than 71 years with a technically adequate incident screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 1,000 to give a rate.

Performance thresholds

S16a: prevalent screen

Acceptable level: greater than or equal to 0.5 per 1,000

S16b: incident screen

Acceptable level: greater than or equal to 0.6 per 1,000

Caveats

Non-invasive carcinoma is calculated including LCIS. Non-operative diagnosis rates may be lower where there is a high proportion of LCIS because these are not reported as malignant prior to surgical confirmation. Services not reaching the acceptable threshold for non-invasive carcinoma should calculate the rate both with and without LCIS for internal monitoring.

Services with a small eligible population (inviting less than 20,000 women per year) should aggregate data over 3 years.

Data collection and reporting

Data source: NBSS (KC62 report, Table A and Table C1). Six-monthly data (provisional) extracted 2 months in arrears, annual data (definitive) extracted 6 months in arrears.

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Six-monthly (provisional data).

Annually (definitive data).

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2017

BSP-S17: outcome: rates of invasive interval cancers

Description

The rate of invasive interval cancers diagnosed per 1,000 women screened. This standard is reported in 3 parts: S17a (less than 12 months of previous screen), S17b (greater than or equal to 12 to less than 24 months of previous screen) and S17c (greater than or equal to 24 to less than 36 months of previous screen).

Rationale

Services should aim to minimise the number of cancers presenting between screening episodes. Interval cancer rates are monitored for educational and service improvement purposes making sure that screening services take the opportunity to diagnose radiologically detectable cancers at screening. The recording of both screen detected and interval cancers allows the performance of the national screening programme to be evaluated. Further information is available in the reporting, classification and monitoring of interval cancers and cancers following previous assessment guidance.

Definition

S17a: less than 12 months from previous screen

Numerator: number of women eligible for screening presenting with an invasive interval cancer less than 12 months from a previous technically adequate screen.

Denominator: number of eligible women aged 50 to less than 71 years registered with a GP with a technically adequate screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 1,000 to give a rate.

S17b: greater than or equal to 12 to less than 24 months of previous screen

Numerator: number of women eligible for screening presenting with an invasive interval cancer greater than or equal to 12 to less than 24 months of a previous technically adequate screen.

Denominator: number of eligible women aged 50 to less than 71 years registered with a GP with a technically adequate screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 1,000 to give a rate.

S17c: greater than or equal to 24 to less than 36 months from a previous screen.

Numerator: number of women eligible for screening presenting with an invasive interval cancer greater than or equal to 24 to less than 36 months from a previous technically adequate screen.

Denominator: number of eligible women aged 50 to less than 71 years registered with a GP with a technically adequate screen in the reporting period.

We calculate performance by dividing numerator by denominator and multiplying by 1,000 to give a rate.

Performance thresholds

S17a: less than 12 months of previous screen

Acceptable level: less than 0.65 per 1,000

S17b: greater than or equal to 12 to less than 24 months of previous screen

Acceptable level: less than 1.40 per 1,000

S17c: greater than or equal to 24 to less than 36 months of previous screen

Acceptable level: less than 1.65 per 1,000

Caveats

Analysis of interval cancer data should take place at screening service level by aggregating several years’ performance. The number of interval cancers occurring in individual screening services each year is relatively small and analysis of them is likely to be meaningful only when at least 3 years’ data are available.

Interval cancers should be examined alongside other screening data (such as SDRs) when considering the performance of a breast screening service. Failure to achieve interval cancer targets may coincide with lower rates of cancer detection and may reflect higher than expected rates of cancer prevalence in the underlying population or failure to meet screening round length targets.

The ability of a screening service to maintain screening round length standards over the period should be analysed as round lengths shorter than the target of 36 months or longer than the target 36 months may have an impact on rates of interval cancer detection.

Data collection and reporting

Data source: SHIM (screening history information manager) via NCRAS (National Cancer Registration and Analysis Service).

Responsible for data quality and completeness: screening service.

Responsible for submission: screening service.

Reported by: screening service.

Published by: screening service.

Reporting period

Annual audit for women aged 47 to 73 years at screening.

Review dates

Date standard introduced: May 2000

Date standard last updated: April 2017