CTAD Chlamydia Surveillance System
Guidance on the collection and reporting of data for CTAD, the surveillance system for all chlamydia tests done in England.
About
The CTAD Chlamydia Surveillance System is the new name for the Chlamydia Testing Activity Dataset (CTAD).
CTAD Chlamydia Surveillance System data is used to provide detailed reports at national and local levels on screening coverage, the proportion of chlamydia tests that are positive and the chlamydia detection rate in England.
UK Health Security Agency (UKHSA) uses chlamydia data combined from the CTAD Chlamydia Surveillance System and the GUMCAD STI Surveillance System to report chlamydia testing activity.
CTAD became mandatory in April 2012, replacing the NCSP and the non-NCSP non-GUM (NNNG) data sources of chlamydia data from non-specialist sexual health services (SHSs). These changes mean that data for 2012 onwards are not directly comparable with the data reported in earlier years.
Resources
Technical guidance and dataset specifications for laboratories submitting data in compliance with the Standardisation Committee for Care Information (SCCI).
CTAD specification and technical guidance
Commissioning laboratory testing
UKHSA encourages commissioners, providers and laboratories to work together to ensure that the data for local CTAD returns are complete. UKHSA has developed information and other resources to help the commissioning of chlamydia activity data collection.
CTAD commissioning guidance, 2015 update
CTAD data quality
As with any surveillance system, CTAD data quality is vital. Reporting high quality data through CTAD is key to informing local sexual health service planning, assessing the impact of the National Chlamydia Screening Programme (NCSP) and monitoring progress towards the Public Health Outcomes Framework chlamydia diagnosis rate indicator.
The CTAD data validation process identified 2 main issues that affect local authority level chlamydia data:
- postcode of residence to ensure tests and diagnoses are assigned to the correct local authority
- testing service type to minimise double-counting between CTAD and GUMCAD and to correctly monitor testing carried out in different settings
Improving data accuracy and completeness will improve the quality of data for different service types.
CTAD data resubmission
Laboratories are encouraged to resubmit CTAD data for any period (including 2012) to the HIV and STI Web Portal when there has been an improvement in the data quality and completeness since the original submission. This data will be available to registered portal users. Any data resubmitted will be reflected in the next annual data release.
Important points to note:
- resubmissions of data will overwrite any previous submissions received
- as usual, any updates to data must be submitted as a quarter (specifically files for individual quarters must be uploaded, rather than one file for multiple quarters)
- labs should inform the CTAD team they intend to resubmit updated retrospective data, prior to uploading it
Submission and reporting deadlines
| Submission period | Reporting deadline |
|---|---|
| January to March 2024 | Friday 10 May 2024 |
| April to June 2024 | Friday 9 August 2024 |
| July to September 2024 | Friday 8 November 2024 |
| October to December 2024 | Friday 7 February 2025 |
Resubmissions can be done anytime, please contact CTAD in advance.
Accessing CTAD data
Information on chlamydia and service provision in England is available on:
- STIs and screening for chlamydia in England annual report, NCSP data tables, infographic and slide set at national and regional level
- chlamydia re-testing following a positive diagnosis report
Information and guidance on sexual and reproductive health at national and local authority level is available on:
- Sexual and Reproductive Health Profiles for interactive maps, charts and tables
- Sexual health, reproductive health and HIV in England: a guide to local and national data for guidance to help health professionals understand the sexual health data available across England and how to access it
- Wider Impacts of COVID-19 on Health (WICH) monitoring tool is designed to allow you to explore the indirect effects of the COVID-19 pandemic on the population’s health and wellbeing
Restricted-access reports for monitoring local, regional and national sexual health priorities are available on the HIV and STI Web Portal (registered NHS and local authority users only):
- local authority STI and HIV epidemiology reports
- GUMCAD STI diagnoses and services reports
- CTAD data quality reports
- NCSP quarterly data tables
- chlamydia re-testing following a positive diagnosis report
The principles for accessing, storing and sharing CTAD data is given in the HIV and STI data sharing policy.
Guidance on data submission requirements for services providing self-sampling tests for sexually transmitted infections (STIs).
GUMCAD and CTAD data submission for STI self-sampling services
CTAD data requests
CTAD data can be requested by completing the CTAD data request form and sending this to ctad@ukhsa.gov.uk
The data team will aim to provide the data within 2 weeks but this may be longer during busier periods such as after the annual data release.
UKHSA sexual health and HIV privacy information
The sexual health and HIV privacy information guidance explains the de-personalised data we collect, how we use it and how we protect this information.
Changes since 2012 in the chlamydia data
Since the Information Standard (ISB 1538) was approved in 2011 by the Information Standards Board for Health and Social Care (ISB), a number of amendments to the dataset are required to reflect changes in health boundaries and service delivery and improve data quality. This Information Standard has been revised to include one new item, an additional coding option within an existing item and retirement of one item. In addition, there are some minor changes to the NHS Data Dictionary coding options to 2 existing data items. These changes have now been accepted by the Standardisation Committee for Care Information (SCCI) – the standard is SCCI1538.
Contact information
For further information, including access permission to the HIV and STI Web Portal, contact the CTAD helpdesk at ctad@ukhsa.gov.uk
Updates to this page
Published 1 April 2012Last updated 9 February 2024 + show all updates
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Updated 'Resources', 'Submission and reporting deadlines', 'Accessing CTAD data' sections and added 'UKHSA sexual health and HIV privacy information'.
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Updated data submission and reporting deadlines.
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Updated data submission and reporting deadlines.
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Updated data submission and reporting deadlines.
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Updated data submission and reporting deadlines.
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Updated the submission and reporting deadlines.
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First published.