Healthy life expectancy: interpreting an imperfect but important measure

Healthy life expectancy as a measure of the country’s health has attracted renewed attention following our recent analysis on trends in the UK. We found it had fallen by about 2 years in the decade to 2022–24 with a widening gap between more and less economically deprived areas.

This attention is not just down to the scale of the decline our work revealed, but because of an ongoing debate over the measure’s usefulness. 

Much of this debate has centred on two questions: its reliability as a measure of population health, and the extent to which worsening mental health – particularly among younger people – reflects real deterioration as opposed to how likely people are to report distress.

Healthy life expectancy is a composite measure. It estimates how many years on average a person can expect to live in good health based on current mortality rates and self-reported good health. While the latter may be shaped by expectations and lived experience, it remains a reliable public health measure and is broadly linked to both morbidity and mortality.

This relationship weakens in more deprived areas, where people often report worse health than measures of morbidity alone would suggest. For example, someone working in a physically demanding job may assess their health differently from someone in a less physically intensive role – even if they share the same diagnosed condition. This implies that self-reported health captures not only illness but also the socioeconomic and environmental circumstances shaping a person’s ability to live well with a health condition.

Although healthy life expectancy is imperfect, no single measure fully captures the health of a nation. It remains one of the few routinely published indicators that provides a sense of how population health is changing – and successive governments have relied upon it to judge progress. For instance, the Labour government employs it as a barometer of success in its health mission, and it features in the renewed women’s health strategy.

How should we interpret healthy life expectancy?

As a combined measure, healthy life expectancy is more difficult to interpret than simpler measures. Rather than capturing a single point at which illness begins, it represents the sum of years in good health across a person’s life. This makes it harder to establish cause and effect and, therefore, to identify policy actions. It is also more sensitive to changes in self-reported health than mortality rate, so underlying trends must be interpreted with care. 

Since the pandemic, fewer people have been responding to the Office for National Statistics (ONS) Annual Population Survey, reducing the numbers used to calculate self-reported health. To mitigate this, the ONS now applies modelling to estimate rates of self-reported good health, including in younger age groups, who are not directly surveyed. This can introduce uncertainty to the estimates, and is particularly concerning given the ONS is reducing its involvement in several key health surveys, limiting our understanding of the nation’s changing health.

So while there is a legitimate debate over methodology, this should not detract from the broader direction of travel – that the nation’s health is declining – identified by our analysis.

What is driving the fall?

According to World Health Organization data, the UK saw one of the sharpest drops in healthy life among comparable countries between 2011 and 2021: the second largest fall among the 21 nations studied, and one of only five where healthy life expectancy declined at all. Similarly, our Health in 2040: projected patterns of illness in England report, based on clinical and administrative health data, found that people in the UK are spending fewer years free from illness.

Beyond the headline figures, it is important to understand changes in healthy life expectancy by the characteristics we can observe: sex, age, location and deprivation.

Over the past decade, healthy life expectancy has fallen more abruptly in women than men. Declines in self-reported health are visible across all working-age groups, not just younger people. London appears to be a relative outlier, with around half of boroughs seeing an increase in healthy life expectancy in this time, perhaps reflecting strong employment opportunities and better public transport. 

Meanwhile, inequalities remain stark between more and less socioeconomically deprived areas: worsening self-reported health in the most deprived areas has contributed to a 0.7-year decline in healthy life expectancy relative to the least.

Some of these declines likely reflect worsening mental health. But they also coincide with rising prevalence of chronic conditions in the working-age population, including diabetes, hypertension and musculoskeletal conditions. Physical ill health can worsen mental health, and mental distress can make physical health harder to manage.

Improvements in UK mortality rates, particularly among 25–49-year-olds, also slowed markedly during the 2010s, more so than in most comparable high-income countries. In 32% of local areas across the UK, life expectancy for both men and women has stalled or fallen over the past decade. In Wales, the figure is 60%.

What part has destigmatising mental health played?

One possible explanation for falling healthy life expectancy is a rise in mental health conditions, particularly among younger people. Some argue that this reflects greater openness and reduced stigma, rather than a real deterioration in mental health.

We have made substantial progress in destigmatising mental health conditions. But it is difficult to see how changing perceptions alone could explain the scale of decline seen over the past decade.

If reduced stigmatism were the main driver, we would expect healthy life expectancy to fall across comparable countries. Instead, the UK’s decline stands out. Evidence from the Adult Psychiatric Morbidity Survey and the interim report into mental health conditions, ADHD and autism from Professor Peter Fonagy points to a real rise in common mental health conditions. These are more common among people facing financial hardship and those living with health-limiting physical conditions. Wider pressures – including recession, austerity, the pandemic and the cost-of-living crisis – have increased insecurity and debt, further worsening mental health.

Most worryingly, rising deaths of despair, including suicides and deaths linked to alcohol and drugs, suggest worsening mental health is not simply an artefact of changing language or awareness. This trend diverges from peer countries, and is particularly worrying in Scotland and the North East of England.

What does all this mean?

Despite its clear limitations, healthy life expectancy remains an important measure to track, because of how it captures people’s lived experience of health and its importance in government policy.

Crucially, trends point to a genuine deterioration in the nation’s health, not simply changing perceptions or reporting. We see the consequences in record numbers of people out of the workforce due to poor health and rising numbers of 16–24-year-olds not in education, employment or training due to work-limiting conditions. 

Nor is the decline shared evenly: the sharpest deterioration has been among women, people in the most disadvantaged communities and working-age adults. Whether the driver is mental or physical health, it remains a health problem, with both mental and physical health closely interlinked.

We need to learn more to explain why healthy life expectancy is declining and identify the most effective interventions. This decline shows people’s health is affecting their ability to live fulfilling lives. As a nation, we must understand these experiences better if we are to design the right support, services and policy responses. 

Healthy life expectancy is an imperfect measure, but it remains a valuable signal of a growing problem. If we focus only on how people die, we fail to understand how they live – and what it takes to keep them healthy in the first place.