Population Health Framework: evidence paper

Annex – Technical note on the aim of the Population Health Framework

This annex provides detail on how the aim of the Population Health Framework (PHF) was developed and outlines how progress towards the aim will be measured.

Rationale for the aim

The PHF has the following aim:

By 2035 we will improve Scottish life expectancy whilst reducing the life expectancy gap between the most deprived 20% of local areas and the national average.

The purpose of this aim is to drive the whole system, preventative aspirations of the PHF and galvanise action and collaboration by being both visible and meaningful to the system and the public.

Developing the aim

This aim was developed based on the following analytical work:

• Reviewing existing aims/targets and evidence on the use of these.
• Stakeholder engagement to discuss the considerations involved in setting an aim.
• Analysis of projected trends on life expectancy conducted by Public Health Scotland (PHS). This included recommendations from PHS for considerations to take into account when developing an aim.

It was clear that an aim for the PHF could take a number of forms. Based on a consideration of the evidence gathered, the following decisions were made which led to the development of the above aim:

Choice of measure

Life Expectancy (LE) was chosen as an appropriate measure due to its objectivity, long standing trend at national and local level and because there are available projections of what we might expect to happen in the future. However, this measure does not track wellbeing or quality of life and improving these are crucial to the success of the PHF.

Healthy Life Expectancy (HLE) is a self-reported, subjective measure which combines mortality data with the UK-wide Annual Population Survey (APS) to understand quality of life based on how people rate their own heath. In recent years, the APS has experienced a significant reduction in response rates affecting the overall quality, meaning we do not have robust local breakdowns of HLE. Scotland’s Chief Statistician has published a statement on these challenges and a Quality Assessment was recently published highlighting the limitations of the data.

Given these technical challenges with HLE, LE was chosen as the preferred measure for the PHF aim. HLE will still be tracked alongside other measures by the Population Health Dashboard, and any changes to the HLE measure will be included as work progresses to address the limitations and improve data quality.

Nature of the aim

Given the First Minister’s priority mission of eradicating child poverty, it is important to ensure addressing inequalities has as much importance as raising overall standards. Therefore, the aim focuses on overall improvement as well as reducing inequalities. This is articulated as aiming to bring the most deprived areas closer to the national average. This keeps a focus on actions and interventions to raise life expectancy in the most deprived areas and is also easily understood.

Timeframe

The ten-year timeframe for the PHF makes it logical to set an aim to be achieved by 2035. Insights from existing data and evidence suggests that ten years is a reasonable timeframe to begin to see quantifiable changes in life expectancy, including reduced inequalities.

Identifying the amount of change desired

PHS undertook bespoke analysis and modelling to understand projected future trends in life expectancy. This analysis is published on the PHS website. The analysis generated projections of male and female estimates of life expectancy at birth and associated levels of uncertainty. This was benchmarked against several different sources of projections and related scenarios. All projections suggest that life expectancy will increase over the time period, but the different methods and underlying assumptions have generated very different projections, and the uncertainty intervals suggest that a decrease is also possible. Due to the significant uncertainty in these projections and the challenges in determining a specific amount of change, PHS recommended that success should not be defined by achieving a specific level, but rather by evidence of sustained improvements in trends over time.

What will success look like?

The PHF evidence paper covers recent trends in life expectancy. This shows how life expectancy stalled and then decreased in some areas. Encouragingly, in 2021-2023 there were slight increases for both males and females, though it remains below pre-pandemic levels.

The PHS paper indicates how future projections all estimate that life expectancy is expected to rise over the next decade, with estimates from National Records of Scotland suggesting potential gains of +1.7 years for females and +1.8 years for males by 2035. However, a decrease is still possible within the confidence intervals and historical trends show that actual figures often fall short of projections, reinforcing the scale of the challenge ahead.

PHS consider that the most compelling evidence of success would be year-on-year gains in life expectancy, in particular, gains which exceed projected estimates which would represent the most aspirational aim. However, given the scale of the challenge, it was decided that success would be defined as both an increase in overall life expectancy and a reduction in inequalities. Reversing declines in life expectancy will be a long-term effort requiring coordinated action across policy areas. Even incremental improvements signal meaningful impact, demonstrating the effectiveness of the approach and actions of the PHF.

How will we assess this?

The aim will be met in 2035 if all of the following is achieved:

• Life expectancy for 2032-2035 is higher than 2021-2023 levels of 76.8 years for males and 80.8 years for females.
• The gap between the national average and the most deprived areas is less than 6.4 years for males and 4.9 years for females^[19].
• Life expectancy in the most deprived areas is higher than 70.4 years for males and 75.9 years for females.

The final condition has been included to ensure that success in reducing inequalities is not achieved through reducing life expectancy in the least deprived areas but that it is an indication of improvements in the most deprived areas.

The baseline has been set at 2021-2023 levels as this represents the latest available data at the publication of the PHF.

The life expectancy figures will be taken from the National Records of Scotland annual publication. Life expectancy in Scotland is calculated as a three-year average, produced by combining deaths and population data for the three-year period. Three years of data are needed to provide large enough numbers to make these figures accurate and lessen the effect of very ‘good’ or ‘bad’ years.

We will provide updates on a regular basis, offering an assessment of progress towards meeting our aim. This will include discussion of the headline life expectancy measure, along with other measures such as healthy life expectancy.

How can progress towards the aim be assessed locally?

Although achieving the aim could be driven by success in some areas while others remain static or even decrease, all local areas (NHS Boards and local authorities) should be looking to achieve the aim.

For areas with particularly high levels of deprivation, there may be need for additional attention as these are the areas which will need to see higher rises to meet the inequalities part of the target.

Turning around trajectories in life expectancy is not a short-term endeavour. The Population Health dashboard provides life expectancy estimates for local areas, alongside a range of other indicators across the key building blocks of health, structured around the Marmot principles. This can enable local users to measure progress and identify where efforts may need to be intensified.

By providing data for local geographies, the dashboard aims to inform local planning work, supporting the work of local partners including NHS Boards, Local Authorities and Community Planning Partnerships. Areas are also able to select different indicators to track, based on what actions they are prioritising.