Table 1.

Structural features of the two research sites

Contextual features	Westward	Eastward
Hospital descriptor	UK acute teaching hospital	UK acute teaching hospital
Location	Inner city	Inner city
Demographics	Mobile population, high ethnic diversity	Mobile population, high ethnic diversity
General medical service	15,000–20,000 patients admitted per year 10 general medical wards	15,000–20,000 patients admitted per year 10 general medical wards
Study ward/beds	General medicine with respiratory specialty/30 beds	General medicine with diabetes specialty/28 beds
Safety systems/tools in use across medical service	Track and trigger toola Critical care outreach teamb	Track and trigger tool
Maternity service	> 6500 births per year Obstetric unit, alongside midwifery unit, antenatal/postnatal ward, antenatal day unit	5500 births per year. Obstetric unit, antenatal/postnatal ward, maternal assessment unit
Study unit(s)	Obstetric unit alongside midwifery unit	Obstetric unit
Safety systems/tools in use across maternity services	Partogramc Track and trigger tool Critical care outreach team	Partogram Track and trigger tool

^aA set of rules to distinguish when vital signs become of concern and appropriate trigger actions that need to be taken as a result.

^bA team set up to facilitate management of acutely ill patients on the ward.

^cA chart to plot the progress of labour to allow for early detection of problems with both mother and baby.