OBSUK: Clinical and cost-effectiveness of a maternity quality improvement programme to reduce excess bleeding and need for transfusion after childbirth: the Obstetric Bleeding Study UK (OBSUK) Stepped Wedge Cluster Randomised Trial

Background: Postpartum haemorrhage (PPH) is the leading cause of maternal morbidity in the UK. There is evidence that rates are increasing with ethnic minorities disproportionately affected. Recent

national reviews and our PPI representatives highlight the need to improve and standardise PPH treatment. A care bundle for managing PPH was developed in Wales, the ‘Obstetric Bleeding Strategy’

(OBS). The bundle consists of: 1) Universal individual assessment of bleeding risk, 2) Real-time accurate measurement of blood loss from birth for all women, 3) A structured and consistent approach

to escalation of care (based on measured blood loss) to more senior clinicians, and 4) A bedside test to rapidly identify abnormal blood clotting (within 10 minutes) and inform treatment if needed. This

contrasts with current UK guidelines which recommend measuring blood loss only after excess bleeding is identified (leading to inconsistent identification and escalation) and giving transfusions based on fixed formulae whilst awaiting laboratory-based test results (around 1 hour). This leads to undertreatment of coagulopathy for some women and unnecessary treatment and transfusions for many others. Although the OBS intervention (OBS care bundle rolled out as a quality improvement (QI) programme) was successfully adopted by Welsh maternity settings (2017-18) and associated with a reduction in massive PPH and blood transfusion, the lack of control and robust clinical and cost effectiveness data has limited more widespread adoption. Maternity staff viewed the OBS intervention positively, with improved teamworking, but further work is needed to establish how the care bundle works. We therefore propose a comprehensive evaluation of the OBS intervention in a randomised controlled trial (RCT).

Aims: To test the effectiveness of the OBS intervention compared to standard care on clinical and psychological outcomes after childbirth, evaluate the cost-effectiveness of the intervention and conduct a process evaluation.

Methods: A stepped wedge cluster RCT in 36 obstetric units over 30 months (approximately 189,000 maternities). The population will be all women booked for maternity care with participating units.

Routinely collected NHS data will be used to measure outcomes including blood transfusion, intensive care admission and hysterectomy rates. Obstetric units will have an initial period of standard care (3-18 months) followed by the implementation of the OBS intervention (9 months) and follow up data collection

(3-18 months). The comparator will be standard PPH care provided by units prior to the OBS intervention. The primary outcome is the proportion of women who receive red blood cell transfusion for

PPH. Secondary outcomes will include the PPH core outcome dataset, effect on psychological wellbeing and cost-effectiveness. The impact of ethnicity, other socio-demographic factors and organisational

culture on outcomes will also be studied using NHS data and in the psychological evaluation and process evaluation.

Anticipated impact and dissemination: This study will establish whether (and how) the OBS intervention improves outcomes and experiences of women and reduces variation in PPH care. Findings will inform national and international PPH practice.