Insights from developing and evaluating the <scp>NHS</scp> blood choices transfusion app to support junior and middle‐grade doctor decision making against guidelines

Objectives: To: 1. Develop a CE-marked smartphone App to support doctors&#39; concordance with transfusion guidelines in non-bleeding adult patients, emphasising informed consent and anaemia management. 2. Test App accuracy and potential to improve user decisions. Background: Studies have shown inappropriate use of blood components and that most junior doctors own smartphones with medical apps. Methods: A multidisciplinary team developed App screens and logic through an iterative process based on national guidelines. Thirty medical or surgical transfusion scenarios were developed based on national guidelines and each sent to Consultant Haematologist experts in Transfusion Medicine. To obtain a clinical consensus and exclude ambiguous scenarios, their independent decisions and associated certainty were compared. The consensus clinical decision was then compared with guidance from the App. To explore potential App impact on simulated user decisions, 26 junior doctors responded to five transfusion scenarios before and after access to the App. Results: The Blood Choices App agreed with 91% (95% CI: 72%–99%) of expert decisions with a sensitivity of 100% (69% to 100%) and specificity of 85% (55%–98%). Excluding one malfunction scenario, the App had the potential to increase correct decisions by junior doctors from 83% (73%–90%) pre-App use to 96% (88%–99%) post (p-value 0.013), with 90% (67%–99%) saying they would use it in practice. Conclusions: Transfusion guidelines can be converted into an App with potential to improve guideline concordance. However, evaluating such Apps is essential to understand their limitations, detect malfunctions and prevent harm.