Table 1

Staffing scenarios

Primary experiments—baseline staffing levels
Standard (core assumption)	Average demand measured by the Safer Nursing Care Tool (SNCT) across 20 days in June* as recommended by the tool guidelines.
Low	80% of average demand measured by the SNCT across 20 days in June*. Lower than the standard either due to vacancies or set to provide bare minimum coverage with high use of flexible staffing.
High	90th percentile of demand measured by the SNCT across 20 days in June*. Designed to meet demand on most days—it is theoretically enough to meet demand through permanent staff on 90% of days.

Secondary experiments—flexible staffing options
Empirical availability (core assumption)	Redeployments and empirical availability of temporary staff (<50% chance of fulfilled requests for all staff types and times of day). Based on data for temporary staffing request fulfilled for one of the participating hospitals.
No temporary staff or redeployments	No redeployments and no temporary staff.
Higher availability	Redeployments and bank/agency staff requests each have 50% chance of being fulfilled. Thus, this assumes higher availability of temporary staff than the core assumption.
Unlimited availability	Redeployments and bank staff requests each have 50% chance of being fulfilled and agency staff requests have 100% chance of being fulfilled.

*Or next month if unavailable. Where needed for wards that have no data, for example, in the second half of the year, we applied the average percentage increase/decrease between January and June for other wards at that hospital.