How efficiency varies across NHS acute trusts
Key points
- The COVID-19 pandemic triggered a decline in NHS efficiency, which has yet to fully recover. Less care is now being delivered than would be expected given the resources available. In response, the government has set a target to achieve 2% annual efficiency growth, partly by narrowing variation in performance.
- This analysis examines the extent of variation across trusts and whether reducing it could improve efficiency nationally. We found that the most efficient trusts are around 1.6 times as efficient as the least – a gap that has remained stable since before the pandemic.
- The overall decline in efficiency mainly reflects inputs (such as staff, equipment and operating costs) increasing at a faster rate than outputs (admissions, appointments, procedures). Between 2018/19 and 2024/25, our measured inputs increased by 30%, with outputs increasing by only 12%, equivalent to an efficiency shortfall of 14%.
- This decline in efficiency is reflected across most trusts, including the highest performers, suggesting that sluggish pandemic recovery reflects system-wide constraints rather than poor performance among a small group of trusts.
- Trusts with lower efficiency levels are disproportionately teaching and research intensive, and current output measures may only partially capture these activities. This highlights the need for more refined efficiency measures to better target areas for improvement.
- While there is some potential to improve system-wide efficiency by reducing variation between trusts, this on its own will not be enough to improve national efficiency over the long term. A more effective approach would combine efforts to reduce variation with broader strategies aimed at improving efficiency across all trusts.
Data sources
We measured outputs using activity data from the Hospital Episode Statistics dataset and publicly available datasets for A&E and outpatient activity in NHS hospitals in England for all years between financial year 2018/19 and 2024/25. For inputs, we used the number of full-time equivalent staff and salaries from publicly available NHS workforce statistics. For bank and agency staff, we used expenditure data supplied directly by NHS England. For other associated inputs, we used expenditures from the Trust Accounts Consolidation datasets.
Approach
We measured trust efficiency for each year based on work by Castelli et al (2014), which calculates the ratio of outputs (cost-weighted activity) to inputs (staff, operating expenditures and the cost of using assets such as buildings or equipment) for each acute trust. Weighting activity by its cost ensures more resource-intensive services contribute more to overall output.
Outputs
Our outputs included activity in admitted patient care (elective and non-elective admissions), outpatient attendances (attended appointments only) and Type 1 (all specialty), Type 2 (single specialty) and Type 3 (urgent treatment centre or minor injury unit) A&E attendances.
These activities were cost-weighted to account for their differing resource-use intensity and as a proxy for their relative ‘value’. For example, a hip operation was given a higher value weighting than an outpatient appointment. For elective and non-elective admissions, we used cost weights from the National Cost Collection by Health Resource Group. We used constant 2024/25 prices to avoid conflating changes in activity costs with genuine changes in output.
In line with other productivity measures, we adjusted the cost weights of activities that can be delivered in multiple care settings with equivalent clinical outcomes. For example, some procedures may be provided either as a day case or elective inpatient admission. Because differences in cost reflect the delivery setting rather than the value of the output produced, we assigned these activities a common cost weight equal to the average of the relevant settings. This adjustment was applied to activities delivered as either day case or elective inpatient admissions and to single-day and multi-day unplanned admissions.
Inputs
Inputs include:
- Workforce: full-time equivalent staff, weighted by their salaries, plus expenditure on bank and agency staff
- Operating expenditure: establishment and premises, drugs (not including high-cost drugs), health care purchases (likely to contain a workforce element), education, research and development, non-pay workforce costs, consultancy, legal, supplies and other operating expenditure
- Costs of capital: includes depreciation and amortisation, which spread the cost of assets (like buildings, equipment or licences) held by a trust
Trust inclusion
We analysed acute, non-specialist NHS trusts with a Type 1, Type 2 or Type 3 A&E department and a complete series of output and input data from 2018/19 to 2024/25. Trusts exhibiting large, unexplained changes in measured efficiency outside the pandemic period were excluded (defined as a year-on-year change exceeding 40% outside of 2019/20–2020/21). While this process has tried to account for large, unexplained fluctuations in recorded activity, unaccounted for recording discrepencies may have impacted efficiency changes.
To account for mergers and organisational reconfigurations, we defined trusts according to their 2024/25 organisational structure and retrospectively mapped predecessor organisations onto them. This produced a consistent panel of 110 trusts observed throughout the study period.
Limitations
Our analysis has several limitations that should be considered when interpreting the results.
Unlike the productivity measures produced by the ONS and the Centre for Health Economics, our measure does not include a quality adjustment. This was a deliberate choice to align the analysis more closely with the NHS England measure being used to assess progress toward the government’s 2% productivity target. As a result, the analysis captures changes in the volume of activity relative to inputs but not changes in the quality of care delivered. This approach has two key implications. First, trusts with more complex case mixes, particularly teaching and specialist trusts, may appear less efficient if the additional complexity of their activity is not fully captured by Health Resource Group cost weights. Second, any post-pandemic changes in quality, such as longer waiting times, worse outcomes or changes in readmission rates are not reflected in this measure.
Our measure of outputs also has some drawbacks. Following established productivity methodologies, we equalised the value weights of activities that can be delivered in either day case or inpatient settings to avoid assigning lower value to equivalent activity delivered more efficiently. Unlike other measures of productivity (for example, from the ONS and NHS England), we were unable to apply similar adjustments where care may be delivered in outpatient settings. This was due to data limitations. Where organisations have made strong progress on shifting more care into outpatient settings, this may not be reflected as productivity gains in this work. The analysis focuses on admitted patient care, A&E and outpatient activity data and does not include some other forms of output, such as diagnostic activity. The efficiency of trusts that have expanded these activities may be understated.
Although inputs were adjusted using the NHS capital and wage deflators, national deflators cannot fully capture variation in costs faced by individual trusts. We partially address this by multiplying staffing inputs by national average pay rates, reducing the influence of local pay differences. However, some trust-specific cost pressures, such as differences in energy and drug procurement costs, may not be fully reflected. As a result, some observed differences in measured efficiency may reflect unobserved variation in input costs rather than underlying efficiency.
Trust Accounts Consolidation data are primarily an accounting dataset and report how resources are recorded for financial reporting purposes rather than how inputs are used in delivering care. There is often a lag between investment and its impact on outputs, meaning increases in inputs may not translate into higher measured productivity in the short term. While accounting methods that spread investment costs over time can help improve alignment, they do not fully capture when or how those investments contribute to care delivery, which can lead to some distortion in productivity estimates.
The use of trust-level measures for this analysis may obscure more substantial variation at the service level. Variation at the Health Resource Group or point of delivery (elective, outpatient etc.) level may be wider, and these may be the levels at which improvement measures are being targeted. Further work is needed to assess variation at a more granular level.
Table 1. Comparison of the Health Foundation’s efficiency measure with existing measures
| Measure | Health Foundation | NHS England (in-year) | ONS annual (England) | Centre for Health Economics (York) |
| Coverage | Acute (non-specialist) trusts | All trusts, with the most reliable estimates for acute trusts (inc. specialist) | Whole system | Whole system |
| Level | Trust | Trust | National | National |
| Frequency | Annual | Monthly (year-to-date) | Annual | Annual |
| Latest value | Up to financial year 2024/25 | H1 2025/26 vs H1 2024/25 | Up to 2022/23 (with experimental quarterly measures more recently) | Up to financial year 2022/23 |
| Quality adjustment? (eg for outcomes/experience) | No | No | Yes – produce quality-adjusted and non-quality-adjusted series | Yes – in quality-adjusted variants |
| Equivalisation | Re-weighted to give equal weight to the same care delivered as overnight or day case care (but does not do the same for outpatient care) | Re-weighted to give equal weight to the same care delivered as overnight stay or outpatient/day case care | Undertaking a phased roll-out of re-weighting for the same procedures across modes of provision (including outpatient/day case/overnight and ambulance with/without conveyance) | Re-weighted to give equal weight to the same care delivered as overnight or day case care |
Figure 1
The decline in efficiency since 2018/19 reflects input growth outpacing output (activity) growth (Figure 1). Across the trusts we analysed, cost-weighted activity in 2024/25 was around 12% higher than in 2018/19. Activity had increased across all major service areas included in our measure: A&E, outpatient care, and day case and inpatient care. Outpatient activity saw the largest rise, increasing by around 18%, compared with approximately 14% growth in A&E and 10% growth in inpatient and day case care. The strong growth in outpatient activity may partly reflect the continued shift of care into outpatient settings. However, inpatient and day case activity have also risen above pre-pandemic levels, suggesting this growth reflects an expansion of overall activity rather than simply a substitution of settings.
Despite this growth in outputs, inputs rose much faster. Between 2018/19 and 2024/25, inputs increased by 30%. Workforce costs increased by 25%, while operating expenditure and cost of capital rose by 36%. Efficiency measured as outputs per worker recovered more strongly than efficiency measured as outputs relative to operating expenditure. This suggests that rising operating expenditure accounts for a larger share of the decline in overall efficiency.
Figure 2
Figure 3
Figure 4 shows that, for trusts at both ends of the distribution, inputs rose far faster than outputs (by around 28–32% versus roughly 10–12%). In both cases, the increase was dominated by operating expenditure rather than workforce costs. In other words, the same pattern of inputs rising faster than outputs and being concentrated on the non-staff side appears among the most efficient trusts as well as the least. If the current efficiency shortfall were a matter of inefficiency being concentrated in least efficient trusts, these input pressures would have been localised in the bottom quartile; that the shortfall appears across the distribution indicates the rising cost of inputs constraining efficiency improvement across all trusts.
Figure 4
Some of these differences may reflect the composition of trusts within each group. Of the 27 trusts in the bottom quartile in 2018/19, 22 remained there in 2024/25. These trusts had higher spending on research and development and accounted for around 40% of teaching trusts nationally. Activities such as research and training may not be fully captured in standard measures of productivity, potentially understating the measured efficiency of these trusts.
In comparison, only 16 of the 27 trusts in the top quartile remained there in 2024/25, suggesting that top-ranking trusts are less stable over time. This group was less research intensive, included a smaller share of teaching trusts and accounted for a slightly smaller share of total cost-weighted activity relative to its share of trusts.
Taken together, these findings suggest that differences in post-pandemic recovery reflect both variation in activity growth and differences in input growth. They also indicate that some of the apparent narrowing of differences between trusts may reflect a natural ‘bounceback’, with initially lower-performing trusts having more room for recovery after the pandemic shock.