Evaluation of modernisation of adult critical care services in England: time series and cost effectiveness analysis

Abstract

Objective: To evaluate the impact and cost effectiveness of a programme to transform adult critical care throughout England initiated in late 2000.

Design: Evaluation of trends in inputs, processes, and outcomes during 1998-2000 compared with last quarter of 2000-6.

Setting: 96 critical care units in England.

Participants: 349,817 admissions to critical care units.

Interventions: Adoption of key elements of modernisation and increases in capacity. Units were categorised according to when they adopted key elements of modernisation and increases in capacity.

Main outcome measures: Trends in inputs (beds, costs), processes (transfers between units, discharge practices, length of stay, readmissions), and outcomes (unit and hospital mortality), with adjustment for case mix. Differences in annual costs and quality adjusted life years (QALYs) adjusted for case mix were used to calculate net monetary benefits (valuing a QALY gain at pound20,000 ($33,170, euro22 100)). The incremental net monetary benefits were reported as the difference in net monetary benefits after versus before 2000.

Results: In the six years after 2000, the risk of unit mortality adjusted for case mix fell by 11.3% and hospital mortality by 13.4% compared with the steady state in the three preceding years. This was accompanied by substantial reductions both in transfers between units and in unplanned night discharges. The mean annual net monetary benefit increased significantly after 2000 (from pound402 ($667, euro445) to pound1096 ($1810, euro1210)), indicating that the changes were relatively cost effective. The relative contribution of the different initiatives to these improvements is unclear.

Conclusion: Substantial improvements in NHS critical care have occurred in England since 2000. While it is unclear which factors were responsible, collectively the interventions represented a highly cost effective use of NHS resources.

Fig 1 Peak periods of implementation of modernisation activities and capacity expansion

Fig 2 Number of critical care beds in England located in general units providing intensive care 1999-2006

Fig 3 Critical care transfers as proportion of admissions (transfers in) and discharges (transfers out) 1998-2006

Fig 4 Early discharges, reported delayed discharges, and discharges directly to normal place of residence as proportion of all discharges 1998-2006

Fig 5 Night discharges and unplanned night discharges as proportion of all discharges 1998-2006

Fig 6 Readmissions within 24 and 48 hours as proportion of all discharges 1998-2006

Fig 7 Relative risk (95% confidence interval) of hospital mortality and unit mortality adjusted for case mix, 1998-2006