Research and analysis

Understanding the burden of UTI hospitalisations in England

Published 15 July 2025

Applies to England

Key findings

Using Hospital Episode Statistics (HES) data, this report found that 189,756 hospital admissions related to urinary tract infection (UTI) occurred in England during the financial year (FY) 2023 to 2024, resulting in a total of 1.2 million NHS bed‑days. This amounted to an average of 6 bed-days per infection, although one-third were admitted for less than a day.

The UK Health Security Agency (UKHSA)’s analysis of ‘payment by results’ data shows that hospital spells where UTIs were the primary diagnosis generated costs exceeding £604 million.

UTI-related hospital admissions have increased by 9% compared to the previous year but remain lower than the 3 years pre-pandemic.

52.7% of admissions involved patients aged 70 years and older.

The highest admission rate was observed in those aged 90 and over, with 3,367 admissions per 100,000 population.

Women accounted for 61.8% of all admissions, though this varied by age:

• under 50: 24.7% female, 5.3% male
• over 50: 37.1% female, 32.9% male

A total of 34.4% of admissions were same-day cases.

Length of stay (LOS) increased with patient age.

The burden of UTIs

UTIs are one of the most common conditions presenting in primary care, and account for a considerable number of GP appointments.

UTIs are typically caused by bacteria, most commonly Escherichia coli (E. coli), and require antibiotic treatment.

As UTIs are common, there are concerns that the volume of antibiotics prescribed is contributing to the growing risk of antimicrobial resistance (AMR). More targeted prescribing of antimicrobials for UTIs is essential as part of the National Action Plan for AMR 2024 to 2029. However, preventing infections where possible would reduce antibiotic prescribing and ultimately reduce the selective pressure that antibiotics have on bacteria, with the aim of reducing AMR.

UTIs caused by antimicrobial-resistant bacteria are more expensive and complex to treat:

• they often require broader-spectrum or intravenous antibiotics, longer hospital stays, which have a greater risk of complications and recurrence
• this increases NHS resource use, the risk of resistant strain transmission, and side-effect burdens for patients

The burden of disease for UTIs is considerable, and across all age ranges is much more common in women. Some patients experience recurrent infections which can have persistent symptoms with significant impacts on numerous aspects of their lives.

In older adult patients, UTIs are associated with delirium and a lowered ability to perform a number of acts of daily living.

UTIs are thought to be the initial infection for approximately half of all E. coli bloodstream infections (bacteraemias) (51.2%), a serious infection that can lead to increased morbidity and mortality.

Hospitalisations for all UTIs require multiple healthcare resources which can exacerbate existing NHS pressures:

• preventing UTIs could help reduce NHS service pressures, including hospital bed shortages and the elective care backlog
• there could also be wider societal benefits, such as fewer workplace absences and reduced caregiver burden

Definitions and data scope

This report provides a descriptive analysis of the burden of UTIs on NHS hospital admissions in England, which have risen by 9% in the previous year.  

Trends are presented using data from the Hospital Episode Statistics (HES) database, based on the records of all patients for one financial year (FY) with a spell that contained a UTI-related primary diagnosis.  

Between 6 April 2023 to 5 April 2024, there were 189,756 UTI-related admissions, accounting for a total of 1.2 million bed days. On average, this amounts to 6 bed days per infection, although one-third of patients were in the hospital for less than a day.

This may be an underestimate due to patients that required treatment via hospital services that occur in the community, for example through provision of Outpatient Parenteral Antimicrobial Therapy (OPAT) services that allow patients to receive intravenous antibiotics at home or in an outpatient setting. This reduces the need for hospital admission while ensuring effective treatment of serious upper renal tract infections or those caused by antimicrobial resistant bacteria.

According to a UKHSA analysis of payment by results data, the total cost of hospitalisations for UTI and associated complications exceeds £604 million.

In this report UTIs are classified as either lower urinary tract UTIs (bladder infections – known as cystitis – widely known as UTIs), or infections in the upper urinary tract (such as pyelonephritis – a kidney infection).

For completeness, UTIs associated with pregnancy and neonatal care have also been included. The majority of hospital episodes use the ICD-10 code where the UTI site was unspecified. The data set consists of admissions that included an episode where the primary diagnosis was an ICD-10 code associated with UTIs. UTIs have been classified in this report into the following disease groups based on the associated ICD-10 codes, as per Table 1.

Table 1. ICD-10 codes

Disease group	ICD-10 codes	Definition
Lower UTIs (affecting the bladder and urethra)	N300	Acute cystitis
	N308	Other cystitis
	N309	Cystitis, unspecified
Pregnancy infections	O23	Infections of genitourinary tract in pregnancy
	O234	Unspecified infection of urinary tract in pregnancy
	O862	Urinary tract infection following delivery
Neonatal infections	P393	Neonatal urinary tract infection
Upper UTIs (affecting the kidneys and ureters)	N10	Acute pyelonephritis
	N136	Pyonephrosis
	N151	Renal and perinephric abscess
UTIs where the site was not specified	N390	Urinary tract infection, site not specified

Note: around 84 % of admissions were coded as upper or unspecified site. Coding limitations mean some unspecified entries may conceal true cases.

Report findings

This report presents UTI admissions (FY 2023/2024, trend from FY 2017/2018 to 2023/2024) and patient demographics in FY 2023/2024, identifying the patient groups that experience the highest burden of disease, and estimating the cost of treatment to the NHS (Table 2).

Table 2. Number of UTI admissions, FY 2023 to 2024

Disease group	Number	Mean age	Male	Female	Mean LOS (days)
Lower UTI	8,823	63.9	46.5%	53.5%	1.2
Pregnancy	14,434	28.4	0%	100%	0.8
Neonatal	628	0	61.9%	38.1%	2.7
Upper UTI	5,790	60.6	43.3%	56.7%	8.4
UTI – site not specified	160,081	64.4	40.9%	59.1%	7.1
Total	189,756	61.3 [note 1]	38.2% [note 1]	61.8% [note 1]	6.4 [note 1]

Note 1: weighted average.

Source: NHS Hospital Episode Statistics

Number of infections per year

Hospitalisations for UTIs were at their lowest in 2020 to 2021, very likely influenced by the COVID-19 pandemic. Since then admissions have slowly increased, although they are still below pre-pandemic levels. In the most recent year, 2023 to 2024, there was an increase in hospitalisations by almost 9% on the previous year. The reason for the increase is unknown. Whilst changes in coding could account for some of this increase, there is no evidence of systematic changes that have occurred in coding over this time period.

Figure 1. Admissions with a UTI ICD-10 as the primary diagnosis, financial years 2017/2018 to 2023/2024

Source: NHS Hospital Episode Statistics

UTIs have long been known to be a large driver of hospital admissions, and so the recent increase is adding to an existing disease burden.

Timing of infections.

There is seasonal variation around a very high background rate of hospital UTI-related admission, with monthly admissions for UTIs ranging between 14,400 and 16,845. The lowest number occurs during the winter to spring months (February to April) and highest across the summer (May to October).

Figure 2. Admissions by month, FY 2023 to 2024

Source: NHS Hospital Episode Statistics

Hospital admissions by age of patients

The demographic data of UTI admissions varied by patient age. Variations by the sex of the patient is explored in the next section. Figure 3 presents the distribution of patients across age groups and by type of UTI. Whilst patient age ranged from 0 years to older than 100, a large proportion (52.7%) of total admissions occurred in patients aged over 70.

Figure 3. Admission by age, FY 2023 to 2024

Source: NHS Hospital Episode Statistics

8.4 % of admissions were recorded in the under 18s group. The highest percentage of childhood admissions was in the 0 to 1 year old group who have almost as many admissions as 2 to 12 year olds, with 3.5% and 3.6% respectively (Table 3). When looked at as a rate per 100,000 of the population, the 0 to 1 group was the fourth highest affected. The lowest number of admissions by age group was recorded in teenagers aged 13 to 17 who account for 1.4% of total admissions.

The number of admissions was comparatively higher in the 18 to 29 year age group. Outside of childhood, the lowest affected age group was 40 to 59.

Admissions increase after the age of 60, with a steeper increase in the 70 to 79 year age group, followed by 80 to 89. Whilst the number of admissions over 90 years appears to drop, when looked at as a rate per 100,000 admissions, they almost double from 1,885.7 in the 80 to 89 group to 3,366.6 in the over 90s group.

Table 3. Admission by age, FY 2023 to 2024

Age group	Number	Percentage	Rate per 100,000
0 to 1	6,553	3.5%	553.0
2 to 12	6,876	3.6%	93.5
13 to 17	2,593	1.4%	74.9
18 to 29	17,906	9.4%	208.6
30 to 39	14,429	7.6%	181.2
40 to 49	8,639	4.6%	119.7
50 to 59	12,694	6.7%	165.4
60 to 69	20,060	10.6%	315.7
70 to 79	37,165	19.6%	746.7
80 to 89	45,291	23.9%	1,885.7
90 and over	17,550	9.2%	3,366.6

Source: NHS Hospital Episode Statistics

The age distribution and average age of patients was found to differ by disease group. Admissions for pregnancy-related infections were most common among patients of childbearing age in their 20s to 30s. Patients with all other UTIs had a wider distribution of ages. For unspecified UTIs and lower UTIs, admissions were primarily observed for those aged 50 to 80, while upper UTIs had a lower age-range, between 50 and 75 years old.

Figure 4. Average age by disease group, FY 2023 to 2024

Source: NHS Hospital Episode Statistics

The box plot visually represents the minimum and maximum values of the range, alongside the outliers. The box plot also shows where the first and third quartile of the data lie, with a line demarking the median.

Hospital admissions by sex of patients

Results are reported by sex of patient. Whilst women comprised 61.8% of admissions (Table 4), the breakdown based on the age and sex of the patients show 2 distinct patterns (Figure 5). Women under 50 years old had the overwhelming majority of UTI admissions; however, above age 50, male and female admission rates become more equal.

Figure 5. UTI admissions by sex of patient, FY 2023 to 2024

Source: NHS Hospital Episode Statistics

Table 4. Data for UTI admissions by sex, FY 2023 to 2024

Age	Female number	Male number	Female % of total cases	Male % of total cases	% Female per age bracket	Female per 100,00 population	Male per 100,00 population
0 to 1	3,534	3,019	1.9%	1.6%	53.9%	298.2	254.8
2 to 12	5,295	1,581	2.8%	0.8%	77.0%	72.0	21.5
13 to 17	2,193	400	1.2%	0.2%	84.6%	63.4	11.6
18 to 29	16,599	1,307	8.7%	0.7%	92.7%	193.4	15.2
30 to 39	12,822	1,607	6.8%	0.8%	88.9%	161.0	20.2
40 to 49	6,482	2,157	3.4%	1.1%	75.0%	89.8	29.9
50 to 59	7,682	5,012	4.0%	2.6%	60.5%	100.1	65.3
60 to 69	10,186	9,874	5.4%	5.2%	50.8%	160.3	155.4
70 to 79	18,001	19,164	9.5%	10.1%	48.4%	361.7	385.0
80 to 89	23,833	21,458	12.6%	11.3%	52.6%	992.3	893.4
90 and over	10,679	6,871	5.6%	3.6%	60.8%	2,048.6	1,318.1
Total	117,306	72,450	61.8%	38.2%	-	-	-

Source: NHS Hospital Episode Statistics

Overall admissions for UTIs were higher for women, particularly those under 50. When pregnancy is excluded, there were 29,466 UTI-related hospital admissions in women of working age, compared to 10,080 for men, which is approximately a 3:1 ratio. When UTIs related to pregnancy are included this figure increases to 43,585, or a ratio of over 4:1.  

This data provides an overview of the patterns for more severe infections but, as the majority of affected women are seen in primary care, they will not appear in this report which uses Hospital Episode Statistics data. The overall disease burden of UTIs is therefore likely to be considerably higher.

Whilst UTIs related to pregnancy partially account for the higher hospital admissions for women, it should be noted that women have higher admissions for upper UTIs (such as pyelonephritis) as per Figure 6. However, the data shows the largest proportion across all age-groups was of unknown UTI sites, so interpretation of those with a reported site should be interpreted with caution.

Figure 6. UTI admissions by sex and disease group, FY 2023 to 2024

Source: NHS Hospital Episode Statistics

Length of stay

Figure 7. Length of stay by sex, FY 2023 to 2024

Source: NHS Hospital Episode Statistics

Average length of stay across all admissions was 6.4 days, but this derives from widely varying admission lengths (Table 5). A total of 34.4% of patients were admitted for less than one day, and were predominantly women. This data is for the episode of care where patients were treated for their UTI, though some may have been in hospital for another reason.

Table 5. Length of stay data, FY 2023 to 2024

Length of stay	Number of patients	Percentage of patients	Total admissions percentage  female	Total admissions percentage male	Percentage of females per LOS
Less than 1 day	65,260	34.4%	24.5%	9.9%	71.3%
1 to 2 days	37,320	19.7%	12.2%	7.5%	62.0%
3 days to 1 week	35,869	18.9%	10.3%	8.6%	54.5%
1 week to 1 month	43,506	22.9%	12.6%	10.3%	54.9%
Over 1 month	7,801	4.1%	2.2%	1.9%	53.7%

Source: NHS Hospital Episode Statistics

A clear trend found in the data was that the length of hospital stay for UTI admissions increases with age (Figure 7). Patients under 50 mostly had stays of less than one week, whereas those over 50 had the highest proportions of patients staying over one week. This likely reflects the pattern of increasing comorbidities that are lengthening hospital stay for older adults, but does align with other evidence to suggest that serious infection from urogenital tract infection does correlate with increased age. Note that mortality was not considered in this analysis.

Figure 8. Length of stay by age group and sex, FY 2023 to 2024

Source: NHS Hospital Episode Statistics

Figure 9: Alternative length of stay by age group and sex, FY 2023 to 2024

Source: NHS Hospital Episode Statistics