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Key points

  • The waiting list for planned hospital care – which stood at 7.21 million in January 2023 – has grown by 58% since just before the start of the pandemic. To help expand capacity and address this backlog the NHS has been looking to independent sector providers (ISPs) to treat more NHS patients.
  • The number of elective care treatments delivered each month has been increasing but has only just recovered to pre-pandemic levels. Small overall increases in the share of NHS-funded elective care delivered by ISPs (up from an average of 7.7% pre-pandemic to 8.7% more recently) hides significant variation across settings (inpatient vs outpatient) and specialties.
  • In this piece we examine the role of ISPs in delivering elective care, focusing on two areas where the ISP share of care has grown significantly: ophthalmology and orthopaedics.
  • The independent sector has rapidly scaled up its delivery of NHS-funded inpatient ophthalmic care, with 4 in 10 (38.6%) procedures conducted by ISPs in February 2022. This has helped overall activity return to pre-pandemic levels.
  • The overall volume of NHS-funded inpatient orthopaedic care has not reached pre-pandemic levels, but the independent sector has recovered its activity levels. ISPs delivered 31.2% of NHS-funded orthopaedic care in February 2022, which represents a growth in their share of care.
  • Much of the growth in ISP-delivered inpatient ophthalmic care comes from cataract procedures, which account for around 60–70% of all inpatient ophthalmic care. ISPs have consistently conducted more than 50% of cataract procedures since January 2022. This suggests the delivery of cataract procedures is both highly amenable to scaling, and attractive to ISPs – which isn’t true of other procedures we’ve explored through this analysis.
  • There is evidence of inequality in receipt of ISP-delivered care related to patient characteristics (ethnicity, deprivation, age and region). White patients are more likely to be treated by the independent sector than any other ethnicity, as are patients living in more affluent areas.
  • The NHS faces a significant challenge to deliver the scale of growth required to bring the waiting list down. The independent sector is showing it can contribute to addressing the elective care backlog in some areas of treatment, but it is likely to play a limited role in fully recovering services and won’t be a substitute for addressing the major problems facing the NHS.


At the end of January 2023, the waiting list for planned, non-urgent specialist care in England stood at 7.21 million. This is 58% longer than in February 2020 (just before the start of the pandemic).

Addressing the elective care backlog remains a major priority for the NHS. The elective care recovery plan, published in February 2022, set out an ambition to scale up elective care delivery by 30% compared with pre-pandemic activity. Much of the initial focus has been on tackling ‘long waits’. The most recent target – prioritising appointments for anyone waiting more than 18 months – is due to be achieved by the end of April this year. Tackling the overall growth in the waiting list will, however, require a much more sustained effort to increase the amount of care delivered, beyond a focus on short-term targets.

Using independent sector providers (ISPs) to deliver NHS-funded elective care is seen by the government as an important way to increase capacity and thereby reduce the waiting list. In practice, this means that after an initial referral by a GP or other clinician, patients can receive NHS-funded treatments in private hospitals. These care pathways usually start in one of two ways: patients are either directly assigned to an ISP through the NHS e-Referral service, or sometimes NHS providers themselves subcontract an ISP to treat patients from their waiting lists.

Over the last two decades the independent sector’s role in delivering NHS-funded care has increased year on year (with a brief lull during the pandemic) and ISPs are now delivering around 9% of all NHS funded treatments. Public perception of the independent sector to deliver NHS care remains divided; while 39% support the measure (even if this means taking away budget from other areas of the NHS), 34% oppose it.

The Elective Recovery Taskforce, launched in December 2022, has a particular focus on helping ‘unlock spare capacity in the independent sector to bust the COVID-19 backlogs and reduce waiting times’. While the use of the independent sector to deliver NHS-funded elective care is not new, expectations of the scale of its contribution are.

In July 2022 we published analysis examining overall trends in ISP delivery of NHS-funded elective care. This raised several important questions about the likely contribution that the independent sector can make to recovery. Can the independent sector provide genuine additional capacity given the finite pool of staff the NHS and independent sector draw on? What implications does the distribution of ISPs across different parts of England have for an inclusive recovery?

This latest analysis focuses on two areas of care: ophthalmology (the treatment of patients with eye conditions including procedures such as cataracts) and orthopaedics (the treatment of patients with musculoskeletal issues, which includes joint replacements). These specialties have the largest waiting lists for elective care (approximately 630,000 for ophthalmology and 800,000 for orthopaedics, including trauma), and also have the highest treatment volumes per month for inpatient care. These are also two specialties in which ISP share has grown significantly.

The data analysis was undertaken on behalf of the Health Foundation by the Strategy Unit. The analysis uses acute inpatient and outpatient data for 2018–2022, gathered via the Secondary Uses Services (SUS) dataset and accessed through the National Commissioning Data Repository (NCDR) platform. A limitation of this dataset is that sub-contracting agreements between NHS providers and ISPs are not always visible within it, which leads to under-counting of how much NHS-funded activity is delivered by ISPs. Full detail of the data and methods used is available on GitHub.


Trends in elective care activity delivered by the independent sector

The total number of inpatient and outpatient treatments delivered each month has been increasing since summer 2022 (Figure 1). While this represents something of a recovery, it remains some way off the increase required to begin bringing the waiting list down.

The independent sector has been able to recover activity volumes slightly more quickly than the NHS, which is not surprising. NHS providers face the challenge of balancing elective activity with competing emergency demands, including ongoing COVID-19 disruption and spikes in admissions for flu – pressures that the independent sector does not face. The independent sector can be selective about which patients it treats. This arrangement is a result of ISPs operating without the broader range of facilities and resources (including intensive care units) to care for patients with complex care needs. Therefore, ISPs may be treating a smaller share of patients with more complex care needs (that require more resources) than NHS providers.

The overall share of NHS-funded elective care delivered by the independent sector stands at 8.7% (average between June 2021 and November 2022) – slightly higher than pre-pandemic average of 7.7% (April 2018 and February 2020).

Figure 1


Patterns of independent sector delivery of NHS-funded ophthalmology and orthopaedic care

Our previous analysis showed that the role of the independent sector varied significantly across different specialties and by care setting (inpatient or outpatient). Here we take a deeper look at ophthalmology and orthopaedics, focusing on inpatient activity where the independent sector has a greater share of total NHS funded activity than outpatient activity. Inpatient activity currently accounts for 35.9% of care in ophthalmology and 28.0% of care in trauma and orthopaedics. These two specialties show quite different patterns (Figure 2), with implications for the role of the independent sector.

In ophthalmology the independent sector has recovered quickly from the disruption of the pandemic, and has continued to expand capacity – increasing the number (to 1.7 times the pre-pandemic level) and share of inpatient treatments delivered each month (to 38.6% in February 2022 from 23.3% pre-pandemic). As a result of the growth in ISP-delivered care, the overall number of treatments being delivered per month has recently risen above pre-pandemic levels.

In orthopaedics, however, the monthly number of inpatient treatments (as of October 2022) remains substantially below pre-pandemic levels. This is because NHS providers are undertaking less activity, and ISPs – while again recovering more quickly than NHS activity – have not increased treatment volumes compared with pre-pandemic. As a result, the share of orthopaedic care delivered by ISPs has increased slightly to around 31.2% in February 2022 compared with 26.8% pre-pandemic.

Figure 2

The example of ophthalmology shows that the independent sector is capable of quite rapidly scaling activity to help deliver more elective care procedures – given the right conditions. But what has prevented the same scaling of ISP delivery in orthopaedics and other specialties? A range of factors might contribute to this. It is beyond the scope of this piece to fully explore these, but our analysis and discussions with stakeholders suggest that factors include:

  • Referral pathways: Part of the reason for the scaling of ISP-delivered ophthalmology care is that referral pathways from high-street optometrists are working more smoothly with ISPs than with the NHS. For other specialties, where referrals are controlled by the NHS, it may be challenging for NHS commissioners to fund a substantial increase in ISP activity even where genuinely additional capacity to treat more patients is present.
  • Amenability to scaling: Simpler procedures are easier to scale up. Cataract surgery – which represents the majority of inpatient ophthalmic elective care (between 60% and 70% since 2018) – is often carried out via day admission under local anaesthetic. Conversely, orthopaedic procedures include things like hip and knee replacements – while these are also relatively simple procedures, surgery is conducted under general anaesthetic and requires hospital stays of 3 days or more. This type of procedure is likely to be harder to scale at pace, particularly given the finite workforce available to deliver care across both the NHS and independent sector.
  • Independent sector infrastructure: Some ISPs are set up to provide a narrow range of care – for example, 1 in 4 (23%) independent sector providers of NHS-funded care deliver only ophthalmic care. It may be cheaper for ISPs to provide high volumes of lower complexity care. Contracting arrangements and regulation may also make it easier for them to enter the market for certain types of care.
  • Financial incentives: The ability to adequately cover costs, or indeed make a profit, when delivering procedures under the NHS tariff may be greater, or at least more consistent, for ophthalmology than for orthopaedics.
  • Managing demand: ISPs need to manage demand for NHS-funded care alongside demand for privately funded care. The demand and income opportunities may be different for ophthalmology and orthopaedics.

Procedure-specific trends

We have also looked at a series of individual procedures to add to our understanding of trends. These procedures account for the majority of all procedures in the two specialties.

In ophthalmology we chose cataract (replacing the cloudy lens inside the eye with an artificial one) and vitreous retinal procedures (including eye injections or laser treatments for conditions such as macular degeneration or diabetic retinopathy) as the most common treatments by volume. However, they show very different patterns (Figure 3).

The number of cataract procedures delivered by ISPs has seen a sustained increase over the past 2 years, increasing from 32.0% in February 2020 to 51.4% in February 2022 and continuing to increase since. This represents a return to a long-term trend following the main period of COVID-related disruption.

For vitreous retinal procedures, while the independent sector share is at a slightly higher level than pre-pandemic (increasing from 12.3% in February 2020 to 14.0% in February 2022), the growth is much less pronounced than for cataracts, and more closely resembles the overall elective care trend.

Figure 3

Many of the possible reasons for the differences between ophthalmic and orthopaedic care delivery likely also help explain the differences at procedure level seen here. For example, inpatient vitreous retinal treatments include more varied and complex procedures, which would be more difficult to rapidly scale. The picture is different for outpatient care, where there has been considerable growth in the independent sector’s share of vitreous retinal work – largely comprised of diabetic retinopathy screening, a more straightforward, homogeneous procedure which is therefore easier to scale.

For orthopaedic procedures (we looked at hip, knee and hand procedures, again because of the volumes) there is very little variation and trends largely mirror the overall picture for orthopaedics – and indeed the overall trend for elective care.

The combination of the lack of variation between orthopaedic procedures, and the difference between cataract and vitreous retinal procedures (the number of NHS-funded cataract procedures delivered by ISPs increased by 1.7 times between February 2020 and February 2022 while the volume of non-cataract ophthalmic procedures stayed more or less stable) reinforces a conclusion that cataract procedures are outliers, rather than true indicators of the potential to scale independent sector delivery.


Variation in the receipt of independent sector care

In the context of NHS England’s commitment to inclusive recovery, understanding which patients may be more or less likely to access ISP-delivered care is important. Here we look at patient demographics (deprivation, ethnicity and age) and geography. Our analysis is limited to activity levels, and clinical need is not accounted for – so we can’t conclude whether differences are due to underlying differences in health status or represent genuine inequality of access – but they raise important questions nonetheless.


For both ophthalmology and orthopaedics, patients living in more affluent areas are more likely to receive NHS-funded care delivered by the independent sector than patients living in more deprived areas. This is more pronounced in orthopaedics, where the gap is around 15 percentage points. As Figure 4 illustrates, despite changes in the proportion of care delivered by ISPs – especially in ophthalmology – the differences by deprivation quintile have seen only relatively small changes.

Figure 4

Differences in the share of care delivered by ISPs could have implications for equality of access. If independent sector care expands more than NHS-provided care, access to care for people in more affluent areas could improve more than for those in poorer areas. Figure 5 shows the recovery in ophthalmology inpatient care (pre- to post-pandemic) by level of deprivation, both in absolute terms and as a percentage. This shows that in the poorest areas, treatment volumes in the latest 12 months were still around 1% lower than pre-pandemic levels, while in the richest areas they were 5% higher than pre-pandemic. This is largely being driven by the faster growth of the independent sector care in more affluent areas.

Figure 5

The situation is different for orthopaedics where there no significant differences in inpatient recovery by level of deprivation – all volumes are down by around 30% compared to pre-pandemic.

Despite uncertainty about causes, given previous research has highlighted socioeconomic inequalities in access to NHS-funded elective care (using hip replacements as a case study), any potential exacerbation of these inequalities by the growing role of the independent sector is worth exploring further. Such inequalities would be of particular concern if it meant there were differences in the speed of access to care, or the quality, safety or outcomes of this care – which is beyond the scope of this analysis.


For ophthalmic care, inequalities exist in care delivered by ISPs. White patients have been consistently more likely to receive NHS-funded care from ISPs, although the rate of increase for the share of care delivered by ISPs (since the main period of pandemic-related disruption) is similar across ethnic groups.

When we look at orthopaedic care, we see a similar pattern. Patients from a white background have been consistently more likely to receive NHS-funded ISP-delivered care. Changes across ethnic groups are fairly similar to the overall trend for orthopaedics. The notable exception is patients from black or black British backgrounds: throughout 2022 the proportion of these patients receiving NHS-funded orthopaedic care from ISPs fell. The reasons for this are unknown.

Previous research has found wide variation in rates for all NHS elective care between ethnic groups, with white patients seeing higher rates of elective treatment than black, mixed and Asian groups prior to the pandemic, and further variations in falls and recovery in elective activity for each ethnic group. The NHS has committed to putting reducing inequalities at the core of recovery plans and the findings of this report underscore the importance of collective action across all providers and local leaders underpinned by more reliable recording of ethnicity data.


Independent sector provision of NHS-funded ophthalmic care is focused on patients aged 60 and older, and it is also among this age group that the rate of increase since the pandemic has been most pronounced – likely a function of the volume of cataract operations that the independent sector delivers, and how this has changed over time.

The share of NHS orthopaedic care provided by the independent sector increases gradually with age, peaking in the 60–79 age group. Compared to ophthalmic care, the differences between each age group are less pronounced.

Of course, these factors are not completely unrelated. Between the two specialties we see varying drivers of differences in access. In orthopaedics we see increases in independent sector provision with increased affluence across all ethnicities. In ophthalmology, affluence seems to result in less of an increase in access, and ethnicity is perhaps playing a greater role. For example, if we take black and mixed ethnicity populations, we see very little variation within ethnic groups between deprivation quintiles 1–4.

Regional variation

We know from previous analysis that geography is important. The backlog of patients waiting for elective care is not evenly distributed across England, and nor is ISP capacity evenly spread.

Our analysis shows there are regional differences in the share of patients receiving ISP-delivered care (Figure 6). These regional differences may also explain some of the variations in the types of patients more likely to receive ISP-delivered elective care.

The share of patients receiving ISP-delivered inpatient ophthalmic care has increased across all regions, compared with the pre-pandemic period. In four regions (the north east and Yorkshire, the north west, the Midlands and the south west) more than 50% of inpatient ophthalmic patients were treated by ISPs in October 2022. Patients in London are the least likely to be treated by ISPs. There is also substantial regional variation in the scale of the increase in the number of ophthalmic treatments carried out by ISPs between February 2020 and February 2022 (ranging from 1.3 to 2.6 times the number carried out in February 2020). This doesn’t seem to result in significant variation in the overall number of treatments delivered in each region – which ranges from 0.9 to 1.1 times the number carried out in February 2020. This suggests that even big differences in the share of care delivered by ISPs, and the rate at which this has changed, is unlikely to be helping some regions address their backlog of elective care more quickly.

The pattern with inpatient orthopaedic care is different. While there have been some increases across the country, particularly towards the end of the time period we look at, the difference is not as marked. The exception is the south west, where more than 50% of patients treated in October 2022 received ISP-delivered care.

Figure 6


Do patients treated by the independent sector experience shorter waits than patients treated by the NHS?

As well as tackling the overall growth in the waiting list, the elective care recovery plan places a big focus on reducing waiting times. The plan committed to eliminating waits of longer than 2 years for elective treatment by July 2022, of over 18 months by April 2023 and of longer than a year by March 2025.

In this context, waiting times for patients receiving treatment from ISPs are of interest for two reasons. Firstly, to understand how ISPs contribute to achieving key waiting time reduction targets, and secondly to identify equity implications if there are differences in the speed of delivering treatment.

In ophthalmology, the NHS was treating patients more quickly than the independent sector in November 2022, whereas in 2018 there was almost no difference – approximately 75% of patients waiting for ophthalmic treatments in England were treated within 3 months, regardless of whether they were being treated by the NHS or an ISP. NHS performance bounced back in 2021 and 2022, but the independent sector has seen that figure drop to below 60% in 2022.

For orthopaedic care, waiting times have increased across both the NHS and ISPs since 2018, though this has been more pronounced for ISPs, resulting in patients facing similar waits regardless of whether they are being treated by the NHS or an ISP.

Figure 7

One interpretation of this analysis is that while ISPs might be supporting activity levels, the waiting times observed suggest that – much like NHS providers – they are struggling to deliver care quickly and based on current evidence are unlikely to help bring down overall waiting lists.



The NHS faces a significant challenge if it is to achieve its aim of increasing the number of elective treatments delivered by 30% (compared with pre-pandemic) by 2024/25, and greater use of the independent sector is seen as a way to help with this.

While there has been a rapid expansion in ISP delivery of ophthalmic care, this has led to only a small overall increase in the total levels of activity for this specialty. This rapid scaling is not happening for most ophthalmic procedures apart from cataracts, or for orthopaedic care. The experience of ophthalmology, and cataract surgery in particular, may provide lessons for scaling ISP care that are transferrable to other areas (such as how referral pathways operate).

However, there are also questions about whether the scale of growth observed with cataract surgery is desirable. Possible downsides include workforce training if there are big reductions in the volume of simple cataract procedures delivered by the NHS, as these are essential for surgical trainee skill development, and other possible impacts on the sustainability of NHS services.

The fact that the trend observed in cataracts is not replicated across other ophthalmic procedures, or across orthopaedics, raises questions about how replicable rapid scaling of this nature is. Factors such as complexity of surgery, referral pathways, comparative incentives (such as profit margin) for delivering different procedures, and longer term investment decisions made by ISPs are all likely to be playing a role. If other areas are not as amenable to rapid scaling of independent sector delivery, especially those with proportionally more very long waits such as orthopaedics, then this might limit the contribution the independent sector can play.

This analysis has also raised further questions about equality of access. Across these two specialties, white patients and patients living in more affluent areas are more likely to receive care delivered by the independent sector. While these differences may reflect variation in complexity and clinical need, it is still implied that some groups are less likely to benefit from increased use of the independent sector. This will affect efforts to achieve an inclusive recovery.

The elective recovery taskforce is expected to report shortly. If the NHS and independent sector can work together more effectively, patients stand to benefit from improved referral pathways, shorter waiting times and more joined up care. But ISP activity is ultimately funded from an NHS budget already stretched by high inflation and other cost pressures. Against a backdrop of an imperative for ICSs to cut costs and deliver financial balance, it may be challenging for the NHS to fund a substantial increase in ISP activity even where genuinely additional capacity to treat more patients is present.

While the independent sector is showing it can contribute to addressing the elective care backlog, it won’t be a substitute for addressing the major problems facing the NHS such as staff shortages, social care issues and underfunding, which caused waiting times for planned treatment to increase before the pandemic.

We are grateful to Steve Wyatt and Alex Lawless at the Strategy Unit who undertook the analysis of Secondary Uses Service (SUS) data and contributed to the interpretation of findings.

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