Improvement Analytics Unit An innovative partnership between NHS England and NHS Improvement and the Health Foundation providing robust evaluation of complex changes in the NHS.


The Improvement Analytics Unit (IAU) is a unique partnership between  NHS England and NHS Improvement and the Health Foundation that evaluates complex local initiatives in health care in order to support learning and improvement.

We evaluate initiatives such as those being delivered as part of the sustainability and transformation partnerships (STPs) and Integrated Care Systems (ICSs). By providing rapid feedback to service leaders and decision-makers at both a local and national level, we help to identify what is working well and what might need to change in the future to improve outcomes.

Over the last decade, a number of national transformation programmes have been established to improve quality and efficiency in health care, often through the provision of more integrated care. The best analytical approaches to evaluate the impact of complex changes such as these are demanding to apply and the required capability is not always available in the NHS.

The Improvement Analytics Unit aims to fill this gap by:

  • providing robust evaluation of complex change to support the development of strong and effective health care systems 
  • identifying whether outcomes for patients have changed following the introduction of a new initiative and to identify, so far as possible, why
  • helping to spread the use of data analytics in the NHS for the purposes of quality improvement
  • strengthening the robustness of the body of evidence available to inform national policy development.  

Our approach

Robustly evaluating the impact of complex change often requires the use of a counterfactual control group. Counterfactual analysis relies on making a comparison between a group of patients who have experienced an intervention with a carefully matched control group who have not. We take a wide range of factors into account so that we can be sure that any differences observed between the two groups are likely to be the result of the intervention.

The team at the Improvement Analytics Unit are experts in the use of counterfactual analysis – one of the most rigorous ways to determine the real impact of interventions.

Supporting improvement

Our aim is to support learning and improvement through evaluation. 

Combining analysis from the Improvement Analytics Unit with local intelligence helps to guide the development of improvement on the ground. We know such improvement is complex and takes time. However along the way, the analysis can be used by those delivering change to bring valuable insights and to identify whether they need to alter their approach (‘course correct’) to improve outcomes.

More about the Improvement Analytics Unit


Improvement Analytics Unit - FAQs

Frequently asked questions (FAQs) regarding the Improvement Analytics Unit (IAU).

Newsletter feature

Improvement Analytics: a new resource in the improvement toolbox

30 June 2016

The NHS has seen a succession of change initiatives. Most significantly in recent years, The Five...


IAU Statistical Analysis Protocols

The IAU statistical analysis protocols are intended to guide analytical processes. They includes the...


Improvement Analytics Unit publications

A collection of our Improvement Analytics Unit publications.


Arne Wolters is Acting Head of the Unit, with joint strategic oversight from Adam Steventon, the Health Foundation’s Director of Data Analytics, and Ming Tang, National Director Data and Analytics at NHS England and NHS Improvement.

For further information, or to register your interest in taking part in an evaluation, please get in contact with Arne Wolters.

Find out more about the Improvement Analytics Unit team

Latest content

IAU Statistical Analysis Protocols

23 January 2020

The IAU statistical analysis protocols are intended to guide analytical processes. They includes the proposed evaluation design, statistical methods, and the limitations of the analysis. 

Evaluating digital first primary care – the challenges ahead

Newsletter blog
29 October 2019

Arne discusses how the increasing use of technology in health care brings new challenges for evaluators.

Not just about the numbers: the power of data to drive change

30 July 2019

Using insight from novel data analysis has the potential to maximise the impact of improvement programmes. Here, Filipe Santos explores new findings on care home residents’ use of emergency services.

The impact of providing an enhanced package of care for care home residents in Nottingham City

July 2019

Examining whether enhanced support had an effect on hospital utilisation for new residents who moved into care homes in Nottingham City.

The impact of providing enhanced support for care home residents in Wakefield

July 2019

Evaluating the early effects on hospital use from the first phase of an enhanced support initiative for older people living in care homes in Wakefield.

Rethinking evaluation: the rigour of rapidity

3 May 2019

Can health service evaluations be both rapid and rigorous? Arne Wolters reflects on his experience with the Improvement Analytics Unit.

Context matters: the contrasting effect of enhancing support in residential and nursing homes

10 April 2019

Enhancing support for care home residents can result in different outcomes in different types of homes. Therese Lloyd explains how context matters.

The importance of good-quality hospital data

17 January 2019

Good quality data not only helps patients receive better care, it makes for better research and analysis too

The impact of integrated care teams on hospital use in North East Hampshire and Farnham

September 2018

This briefing examines the early effects on hospital use of introducing multidisciplinary integrated care teams in North East Hampshire and Farnham.

The impact of providing enhanced support for Sutton Homes of Care residents

June 2018

This report examines the effect of the Sutton Homes of Care vanguard on hospital use for new residents who moved into one of 28 Sutton care homes between January 2016 and April 2017.

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Work with us

We look for talented and passionate individuals as everyone at the Health Foundation has an important role to play.

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