Health Survey for England, 2022 Part 2

This report examines the prevalence of kidney disease using self-report and biological measures, among adults aged 35 and over in England in 2021 and 2022.  

Detailed tables accompanying this report can be accessed here.

• 2% of adults aged 35 and over reported that they had been told by a doctor that they had kidney disease, with the highest prevalence among adults aged 75 and over (5%).  

• Based on estimated glomerular filtration rate (eGFR) and urinary albumin levels, 22% of adults aged 35 and over had chronic kidney disease (stage 1 to 5). 11% had the more severe stages 3 to 5.  

• The prevalence and severity of chronic kidney disease increased with age. Around half of adults aged 75 and over had a chronic kidney disease stage 1 to 5 (48%), including over a third who had the more severe stages 3 to 5 (36%). 

• One in four adults living with obesity and one in five adults who were overweight, aged 35 and over had chronic kidney disease (stage 1 to 5), after accounting for age. 

• Among adults aged 35 and over with chronic kidney disease based on eGFR and urine albumin levels, 1% with stage 1 to 2 and 13% with stages 3 to 5 reported having doctor-diagnosed kidney disease.  

Chronic kidney disease (CKD) is recognised as a global public health problem, due to its association with increased cardiovascular mortality (Couser et al, 2011). Chronic kidney disease is defined and staged using two measures: 

• The estimated glomerular filtration rate (eGFR), a measure of how efficiently the waste product creatinine is filtered from the blood, which reflects kidney function. 

• Albuminuria, the presence of albumin (a protein) in the urine, which is a marker of kidney damage. 

Both eGFR and albuminuria are strong independent risk factors for progression to end-stage renal disease and acute kidney injury, but also all-cause and cardiovascular disease mortality (Gansevoort et al, 2011, Matsushita et al, 2010).  

Chronic kidney disease is classified into stages 1 to 5 based on eGFR and albuminuria levels. No symptoms are found with chronic kidney disease in its early stages (1, 2, 3), but appropriate medication can reduce the risk of progression. Symptoms are more likely as severity increases and stage 5 (end-stage renal disease) may require renal replacement therapy (dialysis or transplantation). Kidney disease may be detected by routine testing in people with diabetes or hypertension. The NHS Vascular Checks Programme, introduced in 2009, includes screening for chronic kidney disease (stages 3 to 5) in people aged 40 to 74 with newly identified type 2 diabetes or hypertension (Source: NHS Health Check). 

Information on kidney disease used in this report was collected in two HSE survey years, 2021 and 2022, from adults aged 35 and over who participated in the health visit.  

Questions on kidney disease were asked during the health visit to all adults aged 35 and over. These consisted of the following questions: 

• Have you ever been told by a doctor that you had chronic kidney disease? 

• Have you ever been told you were being tested for kidney disease? 

• Have you ever been told by a doctor or health professional that you are at risk of kidney disease? 

Doctor-diagnosed kidney disease 

Participants who answered ‘yes’ to the question ‘Have you ever been told by a doctor that you had chronic kidney disease?’ were defined as having doctor-diagnosed kidney disease.  

Renal function 

Two methods were used to assess renal function: through the estimated glomerular filtration rate (eGFR), a measure of how efficiently the waste product creatinine is filtered from the blood; and albuminuria, which is the presence of albumin (a protein) in the urine. 

The estimated glomerular filtration rate (eGFR) 

An eGFR can be calculated using either serum creatinine or cystatin C (referred to as eGFRcreat and eGFRcys respectively). eGFRcreat is generally used as the measure to assess renal function and is calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation which takes into account sex, age and serum creatinine levels (Source: NICE 2021). 

The eGFR was categorised into: 

• 90+ ml/min/1.73m², which is considered normal 

• 60-89 ml/min/1.73m² 

• 30-59 ml/min/1.73m²  

• Less than 30 ml/min/1.73m² 

The eGFR decreases with increasing severity of kidney damage; anything below 60 ml/min/1.73m² was considered abnormal. Abnormal levels indicate kidney disease or acute kidney injury.  

Albuminuria 

Kidney disease is associated with higher levels of albumin in the urine. The presence of albumin in the urine was assessed using the albumin:creatinine ratio (ACR), which correlates well with 24-hour urinary albumin excretion. Non-sex-specific thresholds were used, in accordance with NICE guidelines (Source: NICE 2021). These thresholds are: 

• Up to 3mg/mmol, which is considered normal 

• 3mg/mmol to 30mg/mmol – Micro-albuminuria (defined as small, though raised, excretion of albumin) 

• More than 30mg/mmol - Macro-albuminuria 

Anything above 3mg/mmol is considered abnormal.   

Chronic kidney disease (CKD) stage 

Chronic kidney disease stage was assessed using combinations of the eGFR calculated using serum creatinine and the albumin:creatinine ratio (ACR), in accordance with NICE guidelines (Source: NICE 2021). 

Due to small numbers, the four more severe stages of chronic kidney disease were combined into two groups: 3a/3b and 4/5. The stages of kidney failure and how they have been defined are outlined in Table A below, using 2002 and 2012 KDOQI definitions (Source: KDIGO 2002 and KDIGO 2012). 

2% of adults aged 35 and over had doctor-diagnosed kidney disease. 13% reported that they had been tested for kidney disease, and 5% reported having been told they were at risk of kidney disease.  

The prevalence of kidney disease increased with age, and was highest among the oldest adults aged 75 and older. 5% of adults aged 75 and over had doctor-diagnosed kidney disease. The proportions that reported having been tested for kidney disease or told they were at risk also increased with age. Among adults aged 75 and over, 23% had been tested for kidney disease and 12% were told they were at risk of kidney disease. 

For more information: Table 1

Estimates by region are shown in the tables as both observed and age-standardised. Observed estimates show the actual self-reported levels of testing and diagnosis of chronic kidney disease in each region. Comparisons between regions should be based on the age-standardised data, which account for the different regional age profiles. 

The age-standardised prevalence of reporting having been tested for kidney disease varied by region. It was highest in the North East (21%) and East Midlands (20%) and lowest in the East of England (7%). The prevalence of doctor-diagnosed kidney disease or having been told that they were at risk of kidney disease did not vary by region. 

For more information: Table 2

The English Index of Multiple Deprivation (IMD) is a measure of area deprivation, based on 37 indicators, across seven domains of deprivation. IMD is a measure of the overall deprivation experienced by people living in a neighbourhood, although not everyone who lives in a deprived neighbourhood will be deprived themselves. To enable comparisons, areas are classified into quintiles (fifths). For further information about the IMD, see the HSE 2022 Methods. 

Doctor-diagnosed kidney disease, having been tested for or been told they were at risk did not vary by area deprivation. 

For more information: Table 3

Mean serum creatinine was higher among men compared with women (90.1mmol/L and 71.8mmol/L respectively). It also increased with age from 77.4mmol/L among adults aged 35 to 44 to 85.9mmol/L among adults aged 75 and over.  

The estimated glomerular filtration rate (eGFR) is considered a more precise measurement of renal function than assessing these blood analytes on their own. When eGFR takes into account age, sex and serum creatinine levels it is referred to as ‘eGFRcreat’, or if using age, sex and cystatin C levels it is referred to as ‘eGFRcys’.  

The proportion of adults aged 35 and over with a normal eGFRcreat level (90+ ml/min/1.73m²) was 37%, and an abnormal level (less than 60 ml/min/1.73m²) was 10%. The prevalence and severity of an abnormal eGFR increased with age, from less than 1% of adults aged 35 to 44 (with no adults with levels less than 30 ml/min/1.73m²) to 34% of adults aged 75 and over (including 2% with levels less than 30 ml/min/1.73m²). 

The eGFRcys categorised a higher proportion of adults aged 35 and over as having normal levels. Just under half of adults aged 35 and over had a normal eGFR (49%). However, the eGFRcys also categorised a slightly higher proportion of adults aged 35 and over with an abnormal eGFR (12%). This was particularly the case among older age groups. Just under half of adults aged 75 and over (47%) had an abnormal eGFR less than 60ml/min/1.73m² (compared with 1% of those aged 35 to 44). 

Neither the eGFRcreat or eGFRcys varied by sex. 

For more information: Table 4

Excretion of abnormal quantities of albumin was found in 15% of adults aged 35 and over. This predominately comprised of micro-albuminuria (14% of adults aged 35 and over), rather than macro-albuminuria (1%).  

The proportion of adults with abnormal levels of albumin increased with age. Among those aged 75 and over, 25% had micro-albuminuria, and 2% had macro-albuminuria, compared with 9% and 1% of adults aged 35 to 44.  

For more information: Table 5

Chronic kidney disease stage was assessed using combinations of the eGFR calculated using serum creatinine and the albumin:creatinine ratio (ACR), in accordance with NICE guidelines (Source: NICE 2021). For a more detailed explanation of how chronic kidney disease stages were defined see the Methods and definitions section of this report.  

Among adults aged 35 and over 78% had normal kidney function, and 22% had chronic kidney disease (stages 1 to 5). This proportion was greater among women (24%) compared with men (20%). 11% of adults aged 35 and over had the more severe stages (3 to 5) of chronic kidney disease.  

The prevalence and severity of chronic kidney disease increased with age. Around half of adults aged 75 and over had any chronic kidney disease stage 1 to 5 (48%), and over a third had the more severe stages 3 to 5 (36%). Among adults aged 35 to 44 these proportions were 8% and 1% respectively. 

For more information: Table 6

The English Index of Multiple Deprivation (IMD) is a measure of area deprivation, based on 37 indicators, across seven domains of deprivation. IMD is a measure of the overall deprivation experienced by people living in a neighbourhood, although not everyone who lives in a deprived neighbourhood will be deprived themselves. To enable comparisons, areas are classified into quintiles (fifths). For further information about the IMD, see the HSE 2022 Methods. 

The prevalence of having kidney disease varied by area deprivation. The proportion of adults aged 35 and over who had chronic kidney disease in the most deprived areas was higher than that of adults living in the least deprived areas (30% compared with 15%). 

For more information: Table 7

Body Mass Index (BMI); a widely accepted measure of weight for height, defined as weight in kilograms divided by the square of the height in metres (kg/m²), was used to classify adults as healthy weight, underweight, overweight or obese. For this analysis underweight is grouped with healthy weight due to low base sizes. For more information on how information on BMI was collected see HSE 2022 Adult overweight and obesity report. 

The prevalence of having chronic kidney disease based on eGFR and urine albumin levels was greater with increasing BMI. Among adults aged 35 and over, after accounting for age, one in four (25%) adults living with obesity had chronic kidney disease (stage 1 to 5), as did one in five (20%) adults who were overweight, compared with near to one in seven adults who were a healthy weight or underweight (15%). 

The prevalence of having more severe chronic kidney disease stages 3 to 5 followed a similar pattern. 13% of adults living with obesity and 10% of adults who were overweight, had chronic kidney disease stage 3 to 5 compared with 8% of adults who were a healthy weight or underweight. 

For more information: Table 8

Tables 9 and 10 present two different ways of describing undiagnosed disease in the population. Table 9 shows among those who did not report having doctor-diagnosed kidney disease, the proportion of those with objective chronic kidney disease based on eGFR and urine albumin levels. Table 10 shows the proportion who reported having doctor-diagnosed kidney disease among those with objective chronic kidney disease based on eGFR and urine albumin levels. 

Among adults aged 35 and over with no self-reported doctor-diagnosed kidney disease, 21% had chronic kidney disease (any kidney disease stage 1 to 5), based on their eGFR and urinary albumin levels. 10% had the more severe chronic kidney disease stages 3 to 5. The prevalence of chronic kidney disease among those who did not report doctor-diagnosed kidney disease was higher among women (23%) compared with men (19%). 

Having chronic kidney disease based on objective markers, whilst reporting no doctor-diagnosed kidney disease, increased with age. Among those with no doctor-diagnosed kidney disease, 46% of adults aged 75 and over had chronic kidney disease (stages 1 to 5), compared with 8% of adults aged 35 to 44. A similar pattern was found with more severe stages of chronic kidney disease (stages 3 to 5). 33% of adults aged 75 and over with no doctor-diagnosed kidney disease were found to have chronic kidney disease stages 3 to 5, compared with 1% of adults aged 35 to 44. 

For more information: Table 9

Among adults aged 35 and over with chronic kidney disease based on eGFR and urine albumin levels, only 1% with stage 1 to 2, and 13% with stages 3 to 5 reported doctor-diagnosed kidney disease. 5% of adults aged 35 and over with chronic kidney disease stage 1 to 2, and 24% with chronic kidney disease stages 3 to 5 were told they were at risk of kidney disease. 

For more information: Table 10