Beyond ratios - flexible and resilient nurse staffing options to deliver cost-effective hospital care and address staff shortages: a simulation and economic modelling study
Authors: Griffiths Peter , Saville Christina , Ball Jane E , Jones Jeremy , Monks Thomas 
Published: December 2020

AbstractBackgroundIn the face of pressure to contain costs and make best use of scarce nurses, flexible staff deployment (floating staff between units and temporary hires) guided by a patient classification system may appear an efficient approach to meeting variable demand for care in hospitals.ObjectivesWe modelled the cost-effectiveness of different approaches to planning baseline numbers of nurses to roster on general medical/surgical units while using flexible staff to respond to fluctuating demand.Design and SettingWe developed an agent-based simulation model, where hospital inpatient units move between being understaffed, adequately staffed or overstaffed as staff supply and demand, measured by a classification system (the Safer Nursing Care Tool) varies. Staffing shortfalls are addressed first by floating staff from overstaffed units, secondly by hiring temporary staff. We compared a standard staffing plan (baseline rosters set to match average demand) with a higher baseline ‘resilient’ plan set to match higher demand, and a lower baseline ‘flexible’ plan. We varied assumptions about temporary staff availability. We estimated the effect of unresolved low staffing on length of stay and death, calculating cost per life saved.ResultsStaffing plans with higher baseline rosters led to higher costs but improved outcomes. Cost savings from low baseline staff largely arose because shifts were left understaffed. With limited temporary staff available, the higher baseline ‘resilient’ staffing plan cost £8,653 per life saved compared to the standard plan. The standard plan cost £13,117 per life saved compared to the low baseline flexible plan.Cost effectiveness for higher baseline staff was further improved with high temporary staff availability. With unlimited temporary staff, the high-baseline staffing plan cost £3,693 per life saved compared to the standard plan and the standard plan cost £4,520 per life saved compared with the low-baseline plan. Cost-effectiveness of higher baseline staffing was even more favourable when negative effects of high temporary staffing were modelled.ConclusionFlexible staffing can be guided by shift-by-shift measurement of patient demand, but proper attention must be given to ensure that the baseline number of staff rostered is sufficient. Flexible staffing plans that minimise the number of nurses routinely rostered are likely to harm patients because temporary staff may not be available at short notice. Plans that involve low baseline staff rosters and high use of flexible staff therefore do not represent an efficient or effective use of nurses, whereas higher baseline rosters are more resilient in the face of variation and appear cost-effective.Study registration: ISRCTN 12307968Tweetable abstracEconomic simulation model of hospital units shows low baseline staff levels with high use of flexible staff are not cost-effective and don’t solve nursing shortages.What is already known?Because nursing is the largest staff group, accounting for a significant proportion of hospital’s variable costs, unit nurse staffing is frequently the target of cost containment measuresStaffing decisions need to address both the baseline staff establishment to roster, and how best to respond to fluctuating demand as patient census and care needs varyFlexible deployment of staff, including floating staff and using temporary hires, has the potential to reduce expenditure while meeting varying patient need, but high use of temporary staff may be associated with adverse outcomes.What this paper addsLow baseline staff rosters that rely heavily on flexible staff provide cost savings largely because units are often left short staffed, which results in adverse patient outcomes and increased non staff costs.A staffing plan set to meet average demand appears to be cost effective compared to a plan with a lower baseline but is still associated with frequent short staffing even when using flexible deployments.A staffing plan with a higher baseline, set to meet demand 90% of the time, is more resilient in the face of variation and may be highly cost effective