UK Statistical System UK Statistics Authority Code of Practice
Compliance check

Ed Humpherson to Scott Heald: Temporary suspension of accreditation: Breast Cancer Screening Statistics and Scottish Health Costs

Dear Scott,

Thank you for your letter of 24 February outlining the data quality issues affecting Public Health Scotland’s breast cancer screening statistics and Scottish Health Services Costs (or “Costs Book”) publication.

Given the issues you have described, I agree to your request for the temporary suspension of accreditation for both sets of statistics. I note that you are considering designating these as official statistics in development while you continue your investigations and improvement work. We have published Official Statistics in Development guidance to help producers understand when and how to use this label.

In your letter you explain that the data quality issues affecting the breast cancer data for Scotland has affected all statistics published from 2015/16 onwards. Therefore, the suspension should also cover those earlier releases, and a notice should be published to explain the issue to users and outline the work under way to investigate it. Given this is the second issue with aggregate data from this IT supplier, we welcome your investigation into whether the problem affects other data submissions.

I welcome your commitment to keeping OSR informed as work progresses on both publications. Once the necessary improvements have been delivered, we would be happy to discuss the most appropriate timing for a compliance review to consider the reinstatement of accredited official statistics status.

Yours sincerely

Ed Humpherson
Director General for OSR

Scott Heald to Ed Humpherson: Inpatient, day case and outpatient stage of treatment compliance review: PHS Actions

Dear Siobhan,

Thank you for carrying out the helpful compliance review of the PHS Stage of Treatment statistics. I was delighted that these statistics retained the accredited official statistics status following my team’s work to develop their trustworthiness, value and quality in 2025. I particularly welcome your acknowledgement of our work to ensure the changes to improve the statistics’ relevance and timeliness was conducted transparently and with integrity.

We have made the following changes in response to OSR’s recommendations to enhance users’ understanding of the statistics:

  • Provide more specific guidance about the comparability of waiting times statistics pre and post guidance implementation and more prominent advice about the risks of adding waiting lists together
    • The 28th April publication (based on data up to end of March 2026) will include an updated version of the PHS Impact Assessment (first published in October 2025) incorporating data up to the end of March 2026. Our commentary will be clearer about the size of the change for each of the key metrics and we will refer to this in the monthly report published in April and in future releases where applicable.
    • The 3rd February 2026 monthly publication (based on data up to end of December 2025) reinstated our advice (highlighted in bold) that the number of ongoing waits inpatients, day cases, new outpatients and any other service (e.g. diagnostics) should not be added together to determine the proportion of the total population waiting for these types of care. This warning will be included in future monthly releases and we will proactively engage with users who use the statistics in this way.
  • Explain how these statistics relate to similar measures across the UK
    • The 28th April publication (based on data up to end of March 2026) will identify and summarise key messages from the existing work published by ONS on UK health statistics’ comparability. These insights will continue to be included in future monthly releases. We will also engage with UK contacts and groups to identify other information that we could provide to help users understand what data can and can’t be compared across the UK.

The review also highlighted the need to record and publish details of the full list of roles receiving pre-release access (PRA), review the list regularly and ensure PRA is justified, proportionate and minimised. We work with colleagues in Scottish Government and NHS Boards to coordinate the PRA process and have not, to date, experienced issues arising from misuse or early reporting of information provided via PRA. I share OSR’s commitment to ensuring the PRA process is transparent and robust and have taken the steps outlined below to enhance our approach.

  • From today, the PHS website’s about our statistics page has a new pre-release access transparency section listing the roles that require PRA to all PHS statistics releases as well as those who require PRA to the Stage of Treatment release.
  • As the weeks progress, we will continue to update this new section with PRA details for all other PHS statistics releases.
  • I have reviewed the SoT PRA list and the list of roles who receive PRA for all PHS releases. I am assured that the roles named in those are justified, proportionate and we are appropriately minimising the risk of leaks and disorderly publication. I will of course continue to monitor these lists as we publish them going forward for all other releases.

I am copying this letter to Alistair McAlpine, Scottish Government Chief Statistician and Anita Morrison and Nicola Edge, Heads of Health and Social Care Analysis, Scottish Government, whose teams work with PHS to manage the PRA process and are supporting us to implement the changes outlined above.

Yours sincerely,

Scott Heald

Director, Data and Digital Innovation

Head of Profession for Statistics

Related links: Compliance review of inpatient, day case and outpatient stage of treatment waiting times produced by Public Health Scotland  – Office for Statistics Regulation

Siobhan Tuohy-Smith to Scott Heald: Compliance review of inpatient, day case and outpatient waiting times statistics – Office for Statistics Regulation 

Siobhan Tuohy-Smith to Scott Heald: Compliance review of inpatient, day case and outpatient waiting times statistics

Dear Scott,

We have completed a compliance review of Public Health Scotland (PHS)’s statistics on inpatient, day case and outpatient stage of treatment waiting times against the standards of the Code of Practice for Statistics. The review considered whether these statistics continue to meet the standards of Trustworthiness, Quality and Value and should retain their accredited official statistics status.

Based on the findings of the review, we conclude that the statistics continue to comply with the Code and should retain their accredited official statistics designation. We welcome the improvements that PHS has made, including the move to monthly reporting and the transparent implementation of revised waiting time definitions. The review also identifies a small number of areas where further action is needed, particularly around supporting users to understand comparability over time, clarifying how these statistics relate to similar measures across the UK, and strengthening transparency and central control over pre-release access.

We note that PHS is already progressing work to ensure full compliance with the updated Code of Practice for Statistics (Code 3.0), and we welcome the commitment to embed these requirements as part of ongoing development of the statistics.

I am grateful for the constructive engagement from your team throughout the review and look forward to receiving an update on progress against the recommendations.

I am copying this letter to Mairi Watson, Information Consultant for Planned Care Waiting Times Analytical Team.

Yours sincerely,

Siobhan Tuohy‑Smith
Assessment Programme Lead
Office for Statistics Regulation

Related:

Letter from Scott Heald to Ed Humpherson: NHS stage of treatment waiting times statistics  

Letter from Scott Heald to Ed Humpherson: NHS diagnostics activity and stage of treatment waiting times statistics   

Letter from Ed Humpherson to Scott Heald: NHS diagnostic activity and stage of treatment waiting times statistics   

Rob Kent-Smith to Sean Whellams: Compliance review of direct effects of illustrative tax changes bulletin

Dear Sean

Direct effects of illustrative tax changes bulletin – compliance review

We have completed our compliance review of HMRC’s Direct effects of illustrative tax changes bulletin. While the bulletin is clear and well signposted, it is based on economic modelling rather than observed data, raising questions about its classification as official statistics.

To strengthen transparency and value, we recommend that HMRC:

  • Publish a fuller methodology and further explain model assumptions and uncertainties.
  • Provide additional guidance on appropriate use of estimates.
  • Engage users regularly to inform improvements.
  • Consider whether the “official statistics” label remains appropriate.

We expect these points to be addressed in the spring 2026 update and will continue to engage with you on next steps.

Thank you for your cooperation on this.

Yours sincerely

Rob Kent-Smith

Deputy Head of the Office for Statistics Regulation

Related

Compliance review of Direct effects of illustrative tax changes bulletin

Ed Humpherson to Scott Heald: Assessment of NHS Education Scotland’s workforce statistics

Dear Scott,

Assessment of NHS Education Scotland’s workforce statistics

We have completed our assessment of statistics about the NHS workforce in Scotland produced by NHS Education Scotland (NES): Workforce statistics, CAMHS Workforce statistics and Psychology Workforce statistics. I am grateful for the positive contribution and engagement from the team at NES throughout the assessment process.

As you know, we began an assessment of NHS workforce statistics in 2022, following the change in producer organisation from Public Health Scotland (PHS) to NES. Our early investigations identified that further work was required to ensure that the statistics fully complied with the Code of Practice for Statistics (the Code) so we agreed with you to temporarily pause the assessment process at that time.

Last year your team wrote to me to explain that NES had made substantial progress and was ready to restart the assessment. We restarted our assessment in January 2025. We found that NES has made good progress in its compliance with the Code of Practice for Statistics (the Code). NES has improved its governance processes, engages well with users and improved its published information on quality and methodology.

We have identified six requirements to help strengthen the statistics further, to ensure that they fulfil the expectations of the Code. These focus on publishing statistical policies and governance procedures, reviewing the pre-release access lists, publishing a user engagement strategy, publishing more information on cross-UK comparability, improving the presentation of the statistics (including the coherence of data definitions), and clearly setting out reasons for methods choices.

We judge that the statistics about the NHS workforce in Scotland can be designated as accredited official statistics once we have confirmed that the requirements set out in the report have been met. Addressing the requirements will demonstrate that statistics about the NHS workforce in Scotland meet the highest standards of trustworthiness, quality and public value and comply with the Code. We have agreed with NES that it should meet these requirements within six months and keep us updated on progress.

I am copying this letter to Colin Tilley, lead official at NES.

Yours sincerely

Ed Humpherson
Director General for OSR

Related

Compliance review of statistics about the NHS workforce in Scotland

Scott Heald to Ed Humpherson: Request for Assessment of the NHS Scotland workforce statistics (February 2022)

Ed Humpherson to Scott Heald: Assessment of the NHS Scotland workforce statistics (February 2022)

Mark Pont to Scott Heald: Assessment of the NHS Scotland workforce statistics (August 2022)

Catherine Bromley to Ed Humpherson: Request to re-start assessment of the NHS Scotland workforce statistics (March 2024)

Ed Humpherson to Catherine Bromley: Request to re-start assessment of the NHS Scotland workforce statistics (March 2024)

Rob Kent-Smith to Grant Fitzner: Compliance review of CPI and CPIH statistics

Dear Grant,

Compliance review of CPI and CPIH statistics

We have completed our compliance review of the Consumer Prices Index (CPI) and the Consumer Prices Index including owner occupiers’ housing costs (CPIH) statistics against the Code of Practice for Statistics. Our review looked at how ONS is handling its transformation programme for the consumer price statistics, especially in terms of the Quality and Value pillars of the Code.

Based on the findings of the review, it is our view that, overall, the transformation programme is meeting user needs and improves on current measures. We have seen evidence of assured quality and that the new data and methods are sound and suitable. However, the review makes four recommendations for ONS to address to further support the transformation of these statistics.

The statistics retain their status as accredited official statistics. Given the significance of the changes to consumer price statistics, we have previously noted our intention to re-assess CPI and CPIH once grocery scanner data have been incorporated and embedded. Our decision to re-assess is not in response to any specific concerns about the quality of CPI or CPIH but instead seeks to ensure that we provide appropriate regulatory oversight for these key statistics following a period of significant development.

I am grateful for the positive engagement from your team throughout the review.

I am copying this letter to Michael Hardie, Deputy Director, Prices Transformation; Stephen Burgess, Deputy Director, Prices Production; and Chris Payne, Assistant Deputy Director, Head of Consumer Prices Strategy and Resilience.

Yours sincerely,

Rob Kent-Smith

Deputy Head of the Office for Statistics Regulation

Siobhan Tuohy-Smith to Stephanie Howarth: Compliance review of maternity and births statistics and breastfeeding statistics

Dear Stephanie,

We recently completed a compliance review of Welsh Government’s Maternity and births statistics and Breastfeeding statistics against the standards of the Code of Practice for Statistics. Our review considered whether the Welsh Government can continue to publish the statistics as accredited official statistics. 

Based on the findings of the review, it is our view that the statistics comply with the standards of trustworthiness, quality and value in the Code and should retain their accredited official statistics status. We make three recommendations for enhancing the quality and value of the statistics.  

I am grateful for the positive engagement from your team throughout the review. 

I am copying this letter to Annie Campbell, Head of Population and Community Health Statistics. 

Yours sincerely,

Siobhan Tuohy-Smith 

Assessment Programme Lead 

Related Links:

Compliance review of maternity and births statistics and breastfeeding statistics

Ed Humpherson to Eugene Mooney: Temporary suspension of accredited official statistics status of the Northern Ireland Ambulance Service (NIAS) ambulance statistics within the Northern Ireland Hospital Statistics: Urgent and Emergency Care publication

Dear Eugene

Thank you for your letter regarding the Northern Ireland Hospital Statistics: Urgent and Emergency Care publication, and the change to the data source for ambulance service data.

Given the fact that you have not yet been able to fully familiarise yourself with the new data for the ambulance response times and assure yourself of its quality, I agree to your request to temporarily suspend the accreditation of the NIAS sourced data contained within the Northern Ireland Hospital Statistics: Urgent and Emergency Care publication. This suspension should also apply to previous releases impacted by this quality concern and a notice published explaining to users the concerns you have and the work you are doing to investigate these issues.

I note that you plan to carry out a Quality Assurance of Administrative Data (QAAD) exercise, and there is useful guidance on our website to assist you with this. I also note that you intend to label this part of the statistical release official statistics in development. We have published Official Statistics in Development guidance to help producers understand when and how to use this label.

My team will be happy to liaise with you about the most appropriate timing for a review of the Northern Ireland Hospital Statistics. This will take place once you have completed your review and are assured that the statistics can meet the standards expected by the Code of Practice for Statistics.

Yours sincerely

Ed Humpherson
Director General for Regulation

Related Links: Eugene Mooney to Ed Humpherson: Temporary suspension of accredited official statistics status of the NIAS ambulance statistics within the Northern Ireland Hospital Statistics: Urgent and Emergency Care publication. – Office for Statistics Regulation

Alastair McAlpine to Ed Humpherson: Developing a modern statistical system – A review of Scotland’s Census 2022 – progress in meeting recommendations

Dear Ed,

In February, I wrote to you to let you know that our internal review of the Census had been published. This included four recommendations focussed on learning for the future delivery of strategically important statistical exercises across the Scottish Statistical System.

I have appreciated your support for this work and the recognition of my commitment to assure that leadership and statistical decisions in Scotland are made with appropriate oversight and seniority.

I am therefore writing to set out more detail on how I intend to meet the recommendations and the progress that has been made to date. Focus over the first three months has been on recommendation one with actions also initiated on recommendations two and four, as described in the table below. Work on recommendation three will commence in the latter half of 2025 building on the actions delivered.

RecommendationProgress to dateFuture plans
1. The Chief Statistician should consider activities including a task and finish group to define and identify the ‘Cross-cutting Statistical Components’ of the Scottish Statistical system and other projects.A small task and finish group was set up in March 2025 with representation from across Scottish Government analytical areas. The group produced proposed criteria and an initial list of cross-cutting statistical components which it presented to me in April.The criteria and list of components will be tested with senior statisticians and the Analytical Leadership Group, and the Scotstat Board will be kept informed. Once finalised the list of components will be published on our website and reviewed annually. We will share the list with OSR in a future update.
2. The Chief Statistician should consider opportunities to enable planning and training for the wider statistical profession to be linked to the broader skills needed for the delivery of cross-cutting statistical components by different organisations across the Scottish statistical system.A successful programme of leadership training is already being rolled out to B3 and C1 statisticians – ‘Fit for the Future’. I have tasked my team to explore options for similar development opportunities at C2 level and determining the skills needed at this grade. We have opened discussions with senior statisticians.Discussions with senior statisticians will inform our leadership training offer. Further information will be provided in my next update.
3. The Chief Statistician should consider what mechanisms are required to provide oversight and assurance of cross-cutting statistical components in a holistic way and escalation of key decisions that could impact an integrated statistical system.Prior to this review, the Office of the Chief Statistician had already been restructured to centralise professional functions and support. This work will improve the function that OCS provides on assurance.to the Chief Statistician. Draft guidance on assurance of topical and cross-cutting statistical matters has been developed.Now that a list of critical statistical components has been developed and statistical assurance guidance drafted, we will review it with senior statisticians and the Analytical Leadership Group, keeping the Scotstat Board informed. This will be a focus of our response to the review over the remainder of the current financial year.

I expect these planned actions to support the modernisation of our statistics, build trust and improve the transparency in our statistical decisions and methods.

I am copying this letter to the Minister for Parliamentary Business who has responsibility for statistics within his portfolio, Alison Byrne Chief executive of the National Records of Scotland, Scott Heald of Public Health Scotland, and the co-chairs of the Scotstat Board.

Yours sincerely,

Alastair McAlpine
Chief Statistician

Scott Heald to Ed Humpherson: Temporary suspension of accredited official statistics status of cervical cancer screening statistics

Dear Ed,

My team contacted the Office for Statistics Regulation in March this year when we became aware of an error affecting the data used in the Scottish Cervical Screening Programme statistics for the years 2016/17 to 2021/22i. These statistics report on the number of eligible women (and anyone with a cervix) who have a screening test and provide intelligence about the delivery of this vital public health intervention. The impact of the error on the previously published statistics is relatively small for national-level estimates and does not alter the overall conclusions drawn. The impact is somewhat greater for some sub-groups. It is important to note that none of these issues affected the running of the programme and all those eligible were invited for a cervical screen appropriately.

We have been sharing updates with you as our investigations of the error have progressed. Notices were also added to the previous publications and open data portal to alert users.

We discovered the error as part of our work to develop new statistics about the screening programme to reflect changes to the way it is now implemented and the availability of new data to measure its delivery. Following the discussion with your team on 8th May about publication dates, I am writing to confirm our plans and to request a temporary suspension of this series’ accredited status. The next publication will instead be labelled as official statistics in development due to the methodological changes we have made to these statistics (e.g. using a new data source), the introduction of new KPI measures, and the errors with the previous data. I would welcome a review by your team following the statistics’ publication to determine whether the accredited status can be reinstated following the work we have done to address the previous issues and better meet user needs.

We are planning to release the new statistics, and the revised estimates for the 2016-17 to 2021-22 period, on 29th July 2025, with a preannouncement on 28th May. An explanation of the revisions made and the issues we identified through our work to develop the new statistics will be outlined in an FAQ document to be published alongside the main statistics release. For additional transparency, the code used to identify the eligible population and report on the programme KPIs will also be published. An extract of the FAQ document is provided as an annex to this letter for your information.

I would like to thank your team for their advice and support during our investigation of this issue. I am copying this letter to Alastair McAlpine, Scottish Government Chief Statistician.

Yours sincerely,

Scott Heald

Director, Data and Digital Innovation

Head of Profession for Statistics

 

Related links: 

 

Cervical Screening Data FAQs

What happened?

· The previous method for producing these statistics relied on aggregate data extracted from systems by an external IT provider, who applied all selection criteria and calculations. The new statistics use individual-level data which enabled PHS to identify discrepancies in the previously supplied aggregate data. For example, the time periods for each year not matching the dates in the specification provided and errors in the criteria used to select the eligible population to be included in the statistics.

· In previous publications, the terms “coverage” and “uptake” were used interchangeablyii, although it has always been coverage which has been measured. Both will be presented in the new publication, as the new KPIs for the programme require reporting on both coverage and uptake.

· None of these issues affected the running of the programme and all those eligible were invited for a cervical screen appropriately.

What is different now?

· PHS now receive patient level data extracts and analysts apply agreed methodology to create the cervical screening statistics, including identification of the eligible population for coverage statistics.

· PHS has been working with a group of experts who work across the whole cervical screening and treatment pathway to develop and sign-off the methodology for the new statistics. The R code used to identify the eligible population and report on the programme KPIs will be published alongside the statistics.