Projections of individual conditions: prevalence of key conditions in England over the next 20 years

Key points

  • The prevalence of a given condition increases when the number of people being newly diagnosed is higher than the number of people entering remission or dying. Many of the long-term conditions we analyse currently have no cure, so higher survival rates lead to growing prevalence of illness in the population.
  • We project that 19 of the 20 conditions will increase in prevalence by 2040. The exception is coronary heart disease, which has been positively affected by falling smoking rates and changing prescription patterns. In most cases, these increases are mainly driven by population ageing. For example, without population ageing, the prevalence of hypertension is projected to fall 0.6 percentage points by 2040. With population ageing, it is projected to increase by 3.5 percentage points.
  • The conditions with the largest percentage point increases in prevalence are hearing loss (4.6), hypertension (3.5), diabetes (3.5) and chronic pain (2.6). The causes of these increases vary for each condition.
  • Population growth means that over and above this increased prevalence, there is a further rise in the total number of people diagnosed with illness. Of the conditions that have the largest impact on service use and mortality, the greatest absolute projected increases are for diabetes (1.9 million), chronic pain (1.7 million) and heart failure (1.0 million). We also project over a 30% increase in the number of people living with cancer, COPD or chronic kidney disease.

The number of disease cases in a population is caused by a wide variety of interrelated determinants

The past two centuries of progress in public health, medicine and vaccines have meant that most of the disease burden in developed countries is from non-infectious or non-communicable diseases. The COVID-19 pandemic marked a rare event where an infectious disease took many lives, momentarily shifting the demand for care back towards infectious disease. There is a risk of pandemics disrupting health services in the future, but with long life expectancy, the underlying demand from people with non-communicable diseases will persist.

There are hundreds of non-infectious chronic illnesses affecting people in England. In this report we focus on the 20 conditions in the CMS that together contribute to 65% of disability-adjusted life years in England in 2019 and 73% of those due to chronic illness. To understand more about the potential future of illness in England we need to project the prevalence of these conditions, as well as the future demographics of the country.

The future prevalence of each disease depends on the share of the population diagnosed with the condition to begin with, in 2019 in our case, and the change over time. Each year, there will be an inflow into the pool of people with the condition (incidence) and an outflow from that pool, either through remission or death (whether or not this is death from the disease or with the disease). Prevalence will increase if the inflow is greater than the outflow. The age structure of the population can affect inflows and outflows as both incidence and death are age related. As prevalence is the share of the population affected, the total number affected also depends on population size.

For some conditions our modelled risk factors are a major determinant of disease incidence: for type 2 diabetes, coronary heart disease (CHD) and lung cancer, around 70% of new cases are caused by a combination of these individual-level risk factors (eg smoking and obesity) leaving around 30% unexplained (see our modelling working paper, Figure 4.3). For other conditions, a greater percentage of cases are estimated to be caused by other factors: only around a third of new dementia and asthma cases are attributable to our modelled risk factors. And crucially, due to the limitations of linked data and epidemiological research in the area, for more than half of our 20 conditions there is little or no quantitative evidence of a causal relationship with these risk factors. These include chronic pain and anxiety and depression, common conditions that account for a lot of health needs. For more detail on the inclusion of individual-level risk factors in our model see the modelling working paper, section 4 and the technical appendix.

The prevalence of each condition is affected differently by population change

Using the model and projected trends in risk factors, we estimate the amount of new illness (incidence) and the overall rates of illness (prevalence) and how this is affected by population ageing.

Figure 9 shows projected changes in prevalence rates for the 20 CMS conditions over the next two decades, where prevalence is defined as the percentage of the population with the condition. The teal bars exclude the effect of demographic change. The red bars include demographic change and therefore correspond to changes in the prevalence of illness within age groups.

The conditions with the largest overall projected increases (indicated by the red bars) are hearing loss, hypertension, chronic pain and diabetes. Comparing the length of the teal bars with the red bars shows the relative importance of change in the population structure, which is very different for these conditions. For diabetes, around half of the projected rise in prevalence is through greater prevalence at a given age, and half is due to population ageing (as the risk of type 2 diabetes rises with age). By contrast, all the growth in hypertension is due to the changing structure of the population. The teal bar is negative, meaning that if the population had the same structure in 2040, we would project lower rates of hypertension.

For chronic kidney disease, cancer, COPD, dementia and stroke, the teal bars (which exclude demographic change) indicate that change in prevalence is negative or close to zero. This means all the projected growth in prevalence is attributed to change in the population structure. For dementia, this result is consistent with international evidence, as research indicates that age-specific rates of dementia have fallen over time. That is, rates of dementia among 80-year-olds, for example, are lower than they were two decades ago. Increases in life expectancy do, however, mean that there are more older people, increasing the overall number of people diagnosed with the condition.

Coronary heart disease is the only condition where there is a projected fall in prevalence once demographic change is factored in. This condition has strong epidemiological links with smoking and smoking rates have fallen in England in the recent past with this trend projected to continue. In addition, changes in prescription patterns have played a role in reducing age-specific incidence over time. This reduction in prevalence is projected to occur even with population ageing although the fall would be even greater if the population in 2040 had the same age structure as in 2019.

Figure 9: Projected percentage point changes in prevalence rates by condition for those aged 30 years and older, including and excluding demographic changes, England, 2019 and projected for 2040

Source: Analysis of linked health care records and mortality data conducted by the REAL Centre and the University of Liverpool.

Note: The black capped bars represent uncertainty intervals. IBS is irritable bowel syndrome, COPD is chronic obstructive pulmonary disease, TIA is transient ischaemic attack. Cambridge’s definition of ‘alcohol problems’ incorporates both mental and physical conditions associated with alcohol addiction.

Several key conditions are projected to have millions more cases by 2040

The population is projected to grow as well as change in age structure. Higher prevalence therefore implies an increase in the total number of diagnosed cases of individual conditions. This will feed through into a change in the total demand for care. We estimate the total number of people diagnosed with each condition by applying 2019 and 2040 (projected) prevalence rates of individual conditions to the respective populations aged 30 years and older. These estimates are shown in Figure 10, which indicates the projected rise in the numbers of people diagnosed with conditions that have the greatest effect on health care needs and mortality. Among these conditions, the greatest increase is for diabetes, chronic pain and heart failure.

Figure 10: Projected total number of diagnosed cases for the 10 conditions with the highest impact on health care use and mortality among those aged 30 years and older, including demographic changes, England, 2019 and projected for 2040


Source: Analysis of linked health care records and mortality data conducted by the REAL Centre and the University of Liverpool.

Note: Red shaded bars represent uncertainty intervals. COPD is chronic obstructive pulmonary disease.

Many of the conditions exhibiting the largest growth in absolute numbers, such as diabetes and chronic pain, tend to be managed in primary care settings. In the next section we explore how these projected trends in prevalence are determined by relative levels and trends in incidence and mortality. We discuss how low levels of incidence can still result in a large projected increase in the number of people living in ill health.

Levels of illness in the population are determined by incidence and longevity

The projected increase in the level of a particular illness depends on the cumulative difference between inflows, or incidence, and outflows, in the form of remission and death. The larger the gaps between inflows and outflows, the larger the growth in the prevalence of the condition.

Figure 11 compares the rate of inflow, shown by the teal bars, and the major source of outflow, the rate of people dying with each condition in 2019 (excluding population change), shown by the red bars. We do not have information on rates of remission, which would complete the picture on outflows. This means that for conditions with no or minimal remission, the difference between the two bars gives the change in the prevalence of the condition in that year. However, the difference is less meaningful for conditions such as anxiety and depression where remission is common.

To draw out the implications we focus on conditions where remission is absent or minimal, such as dementia and diabetes. For dementia, there is currently no remission and, as shown in Figure 9 in the previous section, the prevalence is not projected to change if we exclude population change. In Figure 11, we see that there is no significant difference between the bars representing incidence and mortality for 2019: the rates of incidence (inflow) and mortality (outflow) are balancing out. By comparison, for diabetes, where remission is also minimal, mortality rates are around half that of incidence rates. This means that prevalence increased in 2019 and is projected to increase to 2040.

With the exceptions of coronary heart disease (falling) and asthma (rising), we project that rates of incidence for each condition will change very little between 2019 and 2040 based on current trends in incidence and risk factors (modelling working paper, section 5). The changes in prevalence presented in Figure 9 are therefore driven by the cumulative difference between deaths/remission rate and the stable incidence rate.

Figure 11: The rate of new cases compared with deaths for people with each condition aged 30 years and older, per head of population, England, 2019, standardised for age, sex and deprivation


Source: Analysis of linked health care records and mortality data conducted by the REAL Centre and the University of Liverpool.

Note: COPD is chronic obstructive pulmonary disease, IBS is irritable bowel syndrome, TIA is transient ischaemic attack.

Figure 12 uses the example of type 2 diabetes to show how the projected change in prevalence (Figure 9) relates to the difference between incidence and mortality. The teal line gives the projected incidence in each year, excluding demographic change. This is projected to remain more or less at the same level over the next 20 years. The red line indicates mortality rates of people with type 2 diabetes. This is projected to increase due to an increase in the average age of the population with the condition. As the population living with type 2 diabetes gets older, their likelihood of dying of any cause (not just type 2 diabetes) increases. Although mortality is increasing, the incidence rate (teal line) is consistently higher than the mortality rate. This is projected to result in a growth in the number of people living with type 2 diabetes (black line). The greater the difference between incidence and deaths (the gap between the teal and the red line), the steeper the black line.

Figure 12: Incidence, mortality (by any cause) and prevalence for type 2 diabetes patients aged 30 years and older, England, 2013–2040 (projected), standardised for age, sex and deprivation

Source: Analysis of linked health care records and mortality data conducted by the REAL Centre and the University of Liverpool.

Figure 12 excludes projected demographic changes. However, as shown in the previous section, the population is projected to be larger and older and this will have implications for health care resources. Figure 13a shows how this translates into changes in the number of people with type 2 diabetes.

Figure 13a: Number of people with type 2 diabetes, England, 2019 and projected for 2040 (excluding and including the effect of demographic changes)

Figure 13b: Number of people with dementia, England, 2019 and projected for 2040 (excluding and including the effect of demographic changes)

Source: Analysis of linked health care records and mortality data conducted by the REAL Centre and the University of Liverpool.

Note: The black capped bars represent uncertainty intervals.

In Figure 12 we showed that the prevalence of type 2 diabetes is projected to increase between 2019 and 2040. By applying prevalence rates by age to the number of people in different age groups in 2019, we see that there were an estimated 3.4 million people with type 2 diabetes. If there was no change to the population size and structure over the next two decades, with the changing prevalence shown in Figure 12, we project 4.0 million people would have type 2 diabetes in 2040. The population is, however, projected to be larger and older – and this could translate into 5.0 million people with type 2 diabetes by 2040.

As a counterexample, shown in Figure 13b, the prevalence of dementia is projected to fall in individual age groups. That is, if there was no change to the population over the next two decades, we project a reduction in the number of people with the condition between 2019 and 2040 from 680,000 to 660,000. The effect of population ageing, however, means that there are projected to be 1.0 million people with dementia in 2040 – an increase of 45%.

How these projections of illness compare with other research findings

Our findings are in line with other projections carried out in the UK and Europe of overall illness. Kingston et al. (2018) project an expansion of morbidity for England, estimating a rise in multimorbidity, especially complex multimorbidity in older age cohorts through to 2035. Milan et al. (2021) model the burden of disease associated with the 10 most common non-infectious diseases for Germany through to 2060, including coronary heart disease, cancer, COPD, dementia, pain and heart failure, under different scenarios of compression and expansion of morbidity. The authors project that, even assuming a compression of morbidity, increases in life expectancy would translate into a significant increase in the burden of disease.

Guzman-Castillo et al. (2017) forecast that the number of older people with care needs will expand by 25% between 2015 and 2025 for England and Wales. They project the prevalence of illness-related disabilities to stay the same or slightly grow within age groups. Their overarching finding is driven by growth in the size of the population of older people.

Our results are also in line with existing projections of the prevalence of specific conditions. Despite a decrease in the projected incidence and age-specific prevalence rates of dementia, Ahmadi-Abhari et al. (2017) project an increase in the number of people with dementia in England and Wales by 2040, as do Wittenberg et al. (2020) in England to 2040, as well as an increase in those requiring palliative care (Etkind et al., 2017).,, Extrapolating current trends, Maddams et al. (2012) also project an increase in the number of cancer cases, for colorectal, lung, prostate, breast and all cancers combined, in England by 2040. Similar projections have been published for England for the number of COPD cases, and for diabetes.

Many studies have explored the changes to health care delivery as a consequence of the changing demand for health care. The REAL Centre’s launch report documented the rapid expansion of elective care services over the past two decades. It showed how the delivery system can change in response to the external drivers of health care demand. The projections we present here reflect a continuation of trends for many of those same drivers.

Research in this area has tried to break down the growing demand for care into its constituent parts, to better understand the growth we have seen.,,, These studies, using emergency care and some planned care settings between 2000 and 2015, found that successive cohorts, once controlling for age and period effects, used less health care.

This is consistent with the increases in healthy life expectancy that have been recorded over the past decades,, and improvements in disability-free years of life after adjusting for age globally. However, as was discussed in earlier sections of the report, longer life typically brings greater multimorbidity: analysis from the Global Burden of Disease data for England showed that between 2010 and 2019, the total years lived with disability was 8.1 million, an increase of 10% from 2010 and 25% from 1990. Further to these findings, a recent review highlights that across multiple countries and in the UK, expansion in morbidity has been brought about by the fact that life expectancy has tended to grow faster than disability-free and healthy life expectancy.

The findings in this report indicate that demographic factors are likely to be the key driver of the growing multimorbidity in the next two decades. The impact of our projections of population health on NHS funding needs is beyond the scope of this report. This analysis of resourcing will be vital and will be covered in subsequent reports in this programme.

How this increase in ill health is managed by the health and care system remains a key question. Negative cohort effects for health care expenditures (ie reducing health care spending for combinations of age and levels of illness) are not incompatible with our findings of an expansion of morbidity. More time spent in ill health may mean less health care need if, despite increases in prevalence, the severity of these conditions reduces, or their management improves (Manton’s dynamic equilibrium hypothesis).


¶¶¶¶¶ These conditions are: dementia, cancer (all types), chronic obstructive pulmonary disease (COPD), atrial fibrillation, heart failure, constipation, epilepsy, chronic pain, stroke/transient ischaemic attack (TIA), diabetes (type 1 or 2), alcohol problems, psychosis/bipolar disorder, chronic kidney disease, anxiety/depression, coronary heart disease, connective tissue disorders, irritable bowel syndrome, asthma, hearing loss and hypertension.

****** These are the 10 conditions with the highest weighted prevalence in 2040. CMS weights for all 20 conditions can be found in the modelling working paper, Table 8.1.

†††††† In our patient records, diagnosis of chronic pain is based on having at least four prescriptions of analgesics or epilepsy drugs (conditional on not having been diagnosed with epilepsy) in the span of a year. This method will likely lead to underdiagnosis, especially given that over-the-counter medication is available without a prescription. There are multiple ways of defining chronic pain, which is commonly identified through surveys. Public Health England, using the Health Survey for England, estimates that the prevalence of chronic pain in 2017 was 34% for people aged 16 years and older and 53% for people aged 75 years and older.

‡‡‡‡‡‡ The full list of our modelled conditions where remission is absent or minimal is atrial fibrillation, chronic kidney disease, COPD, connective tissue disorders, coronary heart disease, dementia, diabetes, epilepsy, hearing loss, heart failure, hypertension, irritable bowel syndrome, psychosis and stroke or transient ischaemic attacks (TIA).

§§§§§§ A measure reflecting the impact an illness has on quality of life before it resolves or leads to death. The years lived with disability account for the severity of a disability and are typically weighted so that young adult ages are valued higher than infants or the very elderly.

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