Yes / The Patient Safety Huddle (PSH) is a brief multidisciplinary daily meeting held to discuss threats to patient safety and actions to mitigate risk. Despite growing interest and application of huddles as a mechanism for improving safety, evidence of their impact remains limited. There is also variation in how huddles are conceived and implemented with insufficient focus on their fidelity (the extent to which delivered as planned) and potential ways in which they might influence outcomes. The Huddle Up for Safer Healthcare (HUSH) project attempted to scale up the implementation of patient safety huddles (PSHs) in five hospitals - 92 wards - across three UK NHS Trusts. This paper aims to assess their fidelity, time to embed, and impact on teamwork and safety culture. A multi-method Developmental Evaluation was conducted. The Stages of Implementation Checklist (SIC) was used to determine time taken to embed PSHs. Observations were used to check embedded status and fidelity of PSH. A Teamwork and Safety Climate survey (TSC) was administered at two time-points: pre- and post-embedding. Changes in TSC scores were calculated for Trusts, job role and clinical speciality. Observations confirmed PSHs were embedded in 64 wards. Mean fidelity score was 4.9/9. PSHs frequently demonstrated a 'fear free' space while Statistical Process Control charts and historical harms were routinely omitted. Analysis showed a positive change for the majority (26/27) of TSC questions and the overall safety grade of the ward. PSHs are feasible and effective for improving teamwork and safety culture, especially for nurses. PSH fidelity criteria may need adjusting to include factors deemed most useful by frontline staff. Future work should examine inter-disciplinary and role-based differences in TSC outcomes. / The Health Foundation’s Scaling Up Improvement Programme: Round One (2015)