Mixed-methods evaluation of the implementation of IOTA-ADNEX ultrasound triage in NHS secondary care ovarian diagnostic one-stop clinics.

Abstract

Robust evidence supports International Ovarian Tumour Analysis (IOTA)-Assessment of Different Neoplasias in the Adnexa (ADNEX) ultrasound triage at 10% threshold for ovarian cancer (OC) diagnosis to identify women for referral to tertiary gynaecological cancer centres for further management. The IOTA-ADNEX risk prediction model has superior sensitivity compared with the current standard of care triage, Risk of Malignancy Index (RMI-1), yet NHS adoption is limited. In our survey of British Gynaecological Cancer Society clinicians, only 30% (24/79) currently follow an IOTA model, despite 80% (63/79) supporting implementation. We evaluated IOTA-ADNEX implementation within two NHS one-stop clinics (OSC) for suspected OC, examining clinical outcomes alongside implementation barriers and facilitators. Mixed-methods study conducted across two UK NHS hospitals between June 2023 and June 2025. Implementation outcomes were surgical intervention rates comparing IOTA-ADNEX-guided and retrospectively calculated RMI-based management using National Institute for Health and Care Excellence/Royal College of Obstetricians and Gynaecologists thresholds and patient process metrics. 11 qualitative semi-structured interviews were conducted with NHS staff involved in OSC implementation and thematic analysis performed. Of 334 patients, 42% (139) underwent same-day discharge. Using IOTA-ADNEX at a 10% threshold, 10% (32/334) of patients underwent surgery under the general gynaecology and cancer unit team. In comparison, 30% (94/334) would have undergone surgery under the same teams if RMI-based triage had been used. Five themes identified from qualitative analysis: organisational infrastructure, clinical decision-making, communication and pathway definition, professional collaboration and training support, and patient experience. Key facilitators included dedicated clinical leadership, timely decision-making capabilities and quality assurance sessions. Barriers included lack of standardised post-clinic pathways and insufficient staff communication about pathway changes. IOTA-ADNEX implementation in OSC offers high same-day discharge rates and reduction in surgical rates compared with RMI triage. To ensure success, implementation should be supported by adequate infrastructure, training and clear pathways. It requires leadership, comprehensive staff training and robust communication strategies. These findings provide practical guidance for healthcare systems for wider implementation of IOTA-ADNEX.