NHS England is to conduct market engagement to obtain input and feedback in preparation for a potential tender of a Down's Syndrome Screening Quality Assurance Support Service (DQASS) The Down's Syndrome Screening Quality Assurance Support Service (DQASS) is in place to monitor and support the quality and effectiveness of the screening tests for Down's syndrome (T21), Edwards' syndrome (T18) and Patau's syndrome (T13) in England.

The DQASS service supports the NHS Fetal Anomaly Programme by providing statistical services that delivers independent clinical audit data and feedback to screening laboratories and ultrasound practitioners to enable quality assurance and continuous quality improvement.

The analysis undertaken by the service checks the baseline median values, risk algorithm parameter values and population measures, such as age adjusted follow-up rates.

Through meta-analyses, DQASS provides information on effects of factors such as smoking that is used to improve screening performance.

The analyses provided by DQASS is used by the Screening Quality Assurance Service (SQAS) to improve the screening programme through feedback on all aspects of the test to laboratories, ultrasound departments and commercial.

DQASS provides independent audits of screening laboratory and ultrasound data in a standardised and statistically valid format.

The service model includes statisticians who are experts in Down's, Edwards' and Patau's syndromes.

For more detailed information about the DQASS, including reporting, please visit: https://www.gov.uk/guidance/downs-syndrome-screening-quality-assurance-support-service