Introduction The ever-increasing demand for NHS services alongside heavy financial pressures makes the focus on healthcare quality more important than ever before. Patient safety and efficiency are key domains of quality improvement (QI), especially in the operating theatre setting. Operating theatres, being the costliest departments in hospitals are an ideal focus for efficiency gains. The current financial climate of the NHS necessitates a focus on efficiency, whilst also keeping patient safety at the centre of attention.

Aim This review aims to address the question of sustainability in quality improvement, focusing on the two closely linked domains of patient safety and efficiency in the operating theatre setting.

Method This study was a realist review of qualitative and quantitative evidence. Data saturation was reached at 26 papers, however a further 5 studies were fully analysed to confirm this. 8 studies focused on non-technical skills training, 6 focused on checklist implementation, 8 considered process or workflow redesign, and 9 studies relied on other methods. It must be noted however that although interventions are grouped as such, there is significant variability within, and overlap between groups, with some interventions being more complex and incorporating multiple tools as part of the same intervention.

Conclusion The two main concepts to consider refined throughout the review are as follows:

1. A culture of continuous, data-driven quality improvement considering staff needs and perceptions, with support from all levels of an institution, can produce sustained increases in both efficiency and patient safety. Process integration is a vital component of sustainable QI in all stages of planning and implementation.

2. Quality improvement strategies can target patient safety and efficiency in combination, without significant compromise. Consideration of both domains can help align the goals of different stakeholders, enhancing positive staff perceptions and thus participation, resulting in sustained uptake.