Building a population health strategy for Buckinghamshire, Oxfordshire and Berkshire West ICB
In early 2025, Buckinghamshire, Oxfordshire and Berkshire West Integrated Care Board (BOB ICB) enlisted CF’s support to build a medium-term strategy for its population of 1.8 million people, within the context of 50% cuts to its running costs. Rather than narrowing its focus inwards, BOB chose to look at the population first. We worked alongside the ICB and its system partners to build the analytical foundation for this strategy, developing a population segmentation that was specific enough to commission against, owned by the system, and robust enough to inform financial planning.
What was the challenge?
BOB was one of the largest ICBs in England, commissioning £3.6 billion of healthcare across Buckinghamshire, Oxfordshire and Berkshire West. The ICB’s projected financial position was challenged, with a £722 million deficit expected by 2029/30, driven by an ageing population with complex and deteriorating health. Population segmentation analysis showed that those with moderate to high health needs accounted for 24% of the population but 72% of total cost, with the highest need groups generating up to 20 times more A&E attendances and 25 times more emergency admissions per year than the wider population.
Whilst this is a challenge shared by many systems, BOB required a level of specificity of population understanding to inform action. The analysis needed to bring system partners to a shared understanding of where resource was going, why, and what a different model of care could deliver.
The 10 Year Health Plan (July 2025) formalised the direction of travel for ICBs to become strategic commissioners, with accountability for population health outcomes across whole pathways. With our support, BOB had therefore started to build the evidence base ahead of the official policy direction.
What did we do?
CF was commissioned to develop BOB’s medium-term strategy, working closely with ICB leadership and wider system partners throughout.
Throughout, system partners were engaged in the analysis – this included building the segmentation on the ICB’s own linked dataset which system partners recognised, and co-developing strategic choices with clinical, operational and finance leaders.
Population segmentation analysis shows 24% of the population of BOB fall into the moderate and high need segments but account for 72% of the total cost.
What was the impact?
The savings and efficiency opportunities were identified over a 10-year period. Alongside this, the strategy gave the ICB’s leadership a shared, evidence-based understanding of their whole population for the first time, looking across organisational boundaries and linking financial sustainability to health outcomes. This directly informed four core system priority programmes focused on neighbourhood health, clinical service strategy and strategic commissioning, joining up the ICB’s 2025/26 operational planning with its medium-term strategic thinking.
CF continued with the ICB into 2025/26 financial planning, with the population health and prevention opportunity analysis directly informing this. The ICB used the evidence to include more ambitious planning assumptions on mitigating growth and offsetting demand and were able to defend these using the population segmentation analysis.
This analytical foundation remains a priority through significant structural change – in October 2025, BOB and Frimley ICBs came together under joint leadership, and on 1 April 2026 NHS Thames Valley ICB was formally established. NHS Thames Valley ICB is now a single strategic commissioning organisation serving 2.5 million people with a £5.6 billion budget. The new ICB has named a population-first approach as a central principle and has established the Thames Valley Innovation Fund to commission c.£50 million in 2026/27 towards neighbourhood health and elective recovery. CF’s work with BOB provides the foundational population insight to support this.
Our view from our work in BOB and other ICBs is that the most long-standing and impactful plans are not always the most sophisticated ones, but the ones built in collaboration with system partners where financial, clinical and operational leaders have an aligned understanding and ownership of the problem. The technical nature of the analysis involved (e.g. population segmentation) risks producing something rigorous but complex that is not fully owned by the receiving system – so true co-development needs to be central to developing a successful population health strategy.
Client Testimonial
“What set CF apart was how they worked with us rather than around us. They built the analysis on our own data, with our clinical, financial and operational leaders in the room, so by the time we reached conclusions the system already recognised and owned them. That is why the work has stuck.”
Senior Executive
Buckinghamshire, Oxfordshire and Berkshire West ICB
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