The cost of wound care for a local population in England

Abstract

The objective of this study is to estimate the cost of wound care in a local population of approximately 590 000 using results from a wound care audit carried out in Hull and the East Riding of Yorkshire as a basis. Full results of the audit will be published separately. An audit in June 2005 provided information on patients with wounds and on their treatment. This was combined with representative National Health Service unit costs to produce an estimate of the total cost of wound care in 2005–2006. In all, 1644 patients had a total of 2300 wounds (1·44 per patient). Most (74·1%) were treated in the community by district nurses, 21·2% were treated in hospital and 4·8% were treated in residential or hospice care. More than one in four hospital inpatients (26·8%) had a wound. Median duration was 6–12 weeks. Twenty‐four per cent had their wound for 6 months or more, and almost 16% of patients had remained unhealed for a year or longer. One in eight wounds (12·8%) were reported as showing signs of infection. The estimated cost of wound care in 2005–2006 was £15 million to £18 million (£2·5 million to £3·1 million per 100 000 population). Caring for patients with wounds required the equivalent of 88·5 full‐time nurses and up to 87 hospital beds. Wounds are a significant source of cost to patients as well as the health care system. The most important determinant of cost appears to be wound complications which require hospitalisation or which delay hospital discharge. Reducing costs requires a systematic focus on effective and timely diagnosis, on ensuring treatment is appropriate to the cause and condition of the wound and on active measures to prevent complications and wound‐related hospitalisation. These results should be generalisable to other similar populations in the UK and elsewhere.

Introduction

A wound care audit was carried out in June 2005, covering National Health Service (NHS) organisations in Hull and the East Riding of Yorkshire. The aims of the audit were to review current wound care practice and to obtain information on the number of patients with a wound being treated in the area. Full results of this audit will be published separately. The aim of this paper is to estimate the potential costs of wound care in a local population using evidence from the Hull audit as a starting point.

At the time of the audit, NHS services were provided for this population by five organisations: four Primary Care Trusts (PCT) and one acute hospital Trust. PCTs are responsible for providing primary care, community health services and mental health services and for commissioning accident and emergency and hospital care for their covered population (defined by area of residence). The Hull and East Yorkshire Hospitals Trust provides accident and emergency, general and acute hospital services from three sites. The hospital is also a tertiary referral centre for patients living outside its immediate catchment area. The total population covered by these services at the time of the audit was approximately 590 000, and the total health care budget of the four PCTs was approximately £697 million.

Methods

The audit was carried out by a team of tissue viability nurses representing the five NHS Trusts in the area [West Hull PCT, Eastern Hull PCT (now combined to form Hull Teaching PCT), Yorkshire Wolds and Coast PCT, East Yorkshire PCT (now combined to form East Riding of Yorkshire PCT) and Hull and East Yorkshire Hospitals NHS Trust]. District nurses were asked to provide information on each patient on their active caseload with a wound at the date of the audit. Residential homes were included in the questionnaires to district nurses. Nursing homes were contacted individually. A tissue viability nurse visited each ward in the hospital (and the local hospice) over a 2‐day period and recorded information on inpatients with a wound. Information was obtained from ward nursing staff. The tissue viability nurse did not inspect wounds, and no dressings were removed for the purpose of the audit. A separate questionnaire was completed for each patient with a wound. Where a patient had more than one wound, detailed information was collected for the most serious wound (the ‘reference’ wound) as judged by the respondent. The questionnaire was piloted in May 2005.

The audit was coordinated by the clinical effectiveness department of West Hull PCT and the clinical audit department of Hull and East Yorkshire Hospitals NHS Trust. All the data entry and analysis was carried out by these departments.

Information from the audit on the number of patients, the number of wounds and frequency of dressing changes was combined with representative national NHS unit costs to estimate expenditure on dressings, the cost of nurse time and wound‐attributable hospital costs. Details of the methods of calculating each of these costs are provided in the following section.

Results

Patients with wounds

Returns were received for a total of 1644 patients with wounds. Most patients had only one wound, but almost a third (31%) had multiple wounds. The mean was approximately 1·44 per patient, giving a total of around 2300 wounds in the sample population. The majority of patients (74·1%) were treated in the community by district nurses. Around one fifth (21·2%) were treated in hospital. The remainder (4·8%) were treated in residential homes, nursing homes or the hospice. Forty‐three per cent of patients had a surgical or trauma wound [classified as ‘primary closure’ (34%), ‘trauma’ (24%), ‘open’ (15%), ‘dehist’ (11%) or ‘other’ (16%)], two thirds of whom were treated in the community. Other wounds recorded in the sample were pressure ulcers (18·1%) and leg/foot ulcers (38·8%).

On the 2 days of the audit, the average number of hospital inpatients was 1297. Of these, 348 (26·8%) had a wound. Information on prevalence rates in other care settings is not reliable.

Wound duration

Survey respondents were asked: ‘how long has the patient had this wound?’ The median duration of all wounds in the sample was 6–12 weeks. Most were of short duration (46%, less than 6 weeks) but a significant proportion of patients (24%) had their wound for 6 months or more. Almost 16% of patients had remained unhealed for a year or longer.

Wound duration depended on the type of wound (Table 1). Most surgical wounds were of short duration. More than two thirds (70·9%) were less than 6 weeks old and 84% less than 3 months. However, approximately 10% had remained unhealed for at least 6 months and 7% were unhealed for a year or longer. The median duration of surgical wounds was <6 weeks.

Table 1.

Prior duration of reference wound (‘how long has the patient had this wound?’)

Duration	Pressure ulcer (%)	Leg/foot ulcer (%)	Surgical/trauma (%)
<6 weeks	38·0	21·4	70·9
6 weeks to <3 months	26·3	20·5	12·9
3 months to <6 months	15·6	16·2	5·7
6 months to <1 year	9·9	14·4	3·2
1 year and longer	10·2	27·5	7·4

The median duration of pressure ulcers was 6–12 weeks. Almost two thirds (64%) of patients had their ulcer for less than 3 months. One in five had an ulcer for at least 6 months and 10% had remained unhealed for a year or more.

Almost 42% of patients with a leg/foot ulcer had their ulcer for at least 6 months. More than one in four (27·5%) had remained unhealed for a year or longer. The median duration was 12–24 weeks.

Wound infection

Respondents were asked: ‘does the wound show signs of infection? If yes, what are the signs of infection (pus, erythema, small, pyrexia, pallor)?’ Wounds were not inspected at the time of the audit and no microbiology tests were carried out to confirm the presence of infection, so a positive reply here does not necessarily mean that a wound was actually infected.

Almost 13% of wounds were reported as showing signs of infection. Eleven per cent of all wounds and 61% of wounds showing signs of infection had been swabbed within the last 7 days. The rate of reported infection differed by type of wound and by care setting (Table 2). The highest rate was in surgical/trauma wounds (14·3%). The rate in chronic wounds was slightly lower [leg/foot ulcers (13·3%), pressure ulcers (10·4%)]. More than one in four hospital inpatients (26·8%) had a wound at the date of the audit. Of these, 16·2% were reported as showing signs of infection.

Table 2.

Wounds showing signs of infection (‘does the wound show signs of infection?’)

	Reference wounds showing signs (%)
Wound type
Pressure ulcer	10·42
Leg/foot ulcer	13·33
Surgical/trauma	14·29
Care setting
Community	12·47
Hospital	16·20
Residential care	15·58
All wounds	12·80

Frequency of dressing change

One of the important determinants of cost is frequency of dressing change. Respondents were asked: ‘how frequently in a typical week does this patient have their dressing changed (by yourself or by someone else)?’

In hospital, the most common (modal) frequency was daily (Table 3). Forty per cent of patients had a daily change, and the approximate mean was 4·34 changes per week (equivalent to an average dressing wear time of 1·6 days). In the community, the most common frequency was 2–3 changes weekly. The mean was approximately 2·96 changes per week.

Table 3.

Frequency of dressing change [‘how frequently in a typical week does this patient have their dressing changed (by yourself or by someone else)?’]

Frequency of dressing change (per week)	Patients treated in hospital	Patients treated in the community
1	13%	15%
2–3	25%	63%
3–4	22%	9%
7	40%	13%
Mean changes per patient per week	4·34	2·96

It may be that more frequent changes in hospital patients are because of the preponderance of surgical wounds in that setting (73% of wounds in hospital patients are surgical wounds compared with 34% in the community). The median change frequency for surgical wounds is only slightly higher for patients treated in hospital (three to four times per week) than for patients treated in the community (two to three times per week). Across all care settings, slightly more patients with a surgical wound had a daily change (24·5%) than patients with pressure ulcers (17·4%) or leg/foot ulcers (8·9%). Slightly more patients with leg/foot ulcers had dressings changed weekly (16·9%) than patients with a surgical wound (13·9%) or a pressure ulcer (9·2%).

Costs of wound care

The primary purpose of the audit was to obtain information on the number of patients and wounds being treated at a particular point in time. It was not designed to collect information on the cost of wound care to the NHS in Hull. However, the audit data can be used to construct an estimate of the likely costs of wound care in a similar population and to understand the key determinants of cost.

The response rate in the audit was less than 100%, and it is important to adjust for underrecording in order to avoid underestimating the true costs of wound care. Adjustments were made where possible. (i) Replies were received from 16 of the 32 nursing and residential homes in the area. The count of patients with wounds in nursing and residential homes was increased pro rata to take account of non response. Ideally missing returns would have been weighted by the number of residents, but this information was not available. (ii) In East Yorkshire PCT, the tissue viability nurse contacted each district nurse personally to ensure a complete response. This was not possible in other PCTs, and in each of these other areas the reported prevalence was lower than that observed in East Yorkshire. The count of patients with wounds was increased in these other PCTs by setting the ratio of patients with wounds to the covered population to the same ratio observed in East Yorkshire (2·88 per 1000). No adjustment was made to numbers recorded in the acute trust. The net impact of these adjustments was to increase the assumed number of patients with wounds by 34% (from 1644 to 2199). The estimated overall prevalence rate (including hospital patients) was 3·73 per 1000. In future work it will be important to focus on measures to increase overall response rates.

The annual cost to the NHS of wound care in this area in 2005–2006 was estimated to be in the range of £14·74 million to £18·37 million (Table 4). This is between £2·5 million and £3·1 million per 100 000 covered population or approximately 2–3% of the local health care budget.

Table 4.

Estimated cost of wound care to the NHS in Hull and East Yorkshire – 2005–2006

Patients	2199
Wounds	3166
Wound care costs
Dressings and other materials	£3·21 million	17–22%
Nurse time	£6·08 million	33–41%
Inpatient costs	£5·45 million to £9·08 million	37–49%
Total	£14·74 million to £18·37 million

Dressings and other materials

The estimated expenditure on dressings and other wound care products in 2005–2006 in the sample area was £3·21 million.

Total expenditure on wound care products by the four PCTs for the period March 2005 to February 2006 was £2·26 million (IMS data, February 2006). The adjusted number of PCT patients identified in the audit was 1710, with a total of 2462 wounds. The average number of dressing changes was 2·96 per week. Thus, expenditure on dressings per change was approximately £5·96 [£2·26 million/(2462 × 2·96 × 52)]. Applying the same average figure to patients treated in hospital gives an estimate of dressing expenditure of £0·674 million (£5·96 × 501 × 4·34 × 52). Expenditure in other sectors was approximately £0·273 million (£5·96 × 203 × 4·34 × 52). The total is £3·21 million.

Nurse time

Nurse time includes direct patient contact time required for dressing changes and travel time for patients treated at home. It does not include any other wound‐related activities (such as risk assessment, monitoring wound condition or turning patients at risk of pressure damage). The estimated total cost of nurse time in 2005–2006 was £6·08 million.

For patients treated in the community, nurse time is costed at £19 per dressing change (at 2005–2006 prices). This is a weighted average of the cost per home visit (£20 including travel) and per clinic visit in the NHS (£13·3 per 20 minutes) assuming 80% of patients are seen at home [(Curtis and Netten, Table 9.1 (1)]. For patients treated in hospital, the cost is £38 per hour of patient contact [Curtis and Netten, Table 13.4 (1)]. For hospital patients, nurse time per dressing change is a weighted average of 10 minutes per change for uncomplicated surgical wounds and 20 minutes for other wounds [mean = 13·7 minutes (0·63 × 10 minutes + 0·37 × 20 minutes)].

Inpatient costs

For most patients treated in hospital, no additional costs are incurred over and above the cost of dressing changes. Only a small proportion of hospital inpatients with wounds have been admitted specifically for the care of their wound, or their discharge has been delayed because of wound infection or other complications.

The Hull audit did not collect information on the reason for hospital admission or on the incidence of delayed discharge. In the absence of better evidence, additional inpatient costs have been estimated on a range of assumptions. Costs are calculated assuming that between 15% and 25% of inpatients with a wound were in hospital on the day of the audit specifically because of their wound. This range appears plausible. On the day of the audit, 22% of the 348 inpatients with a wound had a chronic ulcer (pressure ulcer, leg/foot ulcer). Many of these patients will have been admitted because of that wound. In addition, 16% of wounds in hospital patients were described as showing signs of infection and many of these will be subject to delayed discharge. In future work, it should be possible to identify more precisely which inpatients have been admitted for wound treatment or which patients have had their discharge delayed because of a wound.

Inpatient costs are calculated using a weighted average of daily rates imputed from National Reference Costs for 2005–2006. Specifically, mean costs for non elective inpatients in Health Research Group (HRG) codes J41/J42 (major skin infection) and J45 (minor skin infection) have been combined with average length of stay for each HRG to give a weighted average inpatient cost of £286 per day (2). This cost includes ‘hotel’ costs and the cost of surgical and/or medical procedures attributable to patients admitted specifically for treatment of wound infection.

The estimated cost of inpatient treatment for wounds ranges between £5·45 million (assuming that 15% of wound patients are in hospital specifically for their wound) and £9·08 million (25%). These estimates are subject to a high degree of uncertainty both as to the relevant daily inpatient cost and to the number of hospital inpatients affected.

Resource costs

In addition to the budgetary cost of dressings and other materials, the resource cost (or opportunity cost) of wound care includes the time of nurses and other professionals and hospital beds occupied by patients with a wound (Table 5).

Table 5.

Estimated resource costs of wound care to the NHS in Hull and East Yorkshire – 2005–2006

Patients	2199
Wounds	3166
Resource costs
Dressings and other materials	£3·21 million
Nurse time (hours)	151 000 hours
Nurse time (full‐time equivalents)	88·5 fte
Inpatient cost (bed‐days)	19 000–31 000 bed‐days
Inpatient cost (beds)	52–87 beds

Assuming an average 20 minutes per dressing change and 10 minutes travel time for the 80% of district nurse visits that take place at home, dressing changes alone may have required more than 122 000 hours of district nurse time. This is equivalent to 71·8 full‐time district nurses (based on a 38‐hour week, 45 week working year). In the hospital, assuming a weighted average of 13·7 minutes per change, dressing changes might have required the equivalent of 10·49 full‐time nurses. If 15–25% of the 348 hospital inpatients with a wound were in hospital specifically because of the wound, this would be equivalent to 52–87 beds occupied daily or up to 31 000 bed‐days annually.

Discussion

Wounds are a significant source of cost to patients, nurses and the health care system. The impact of chronic wounds on patient quality of life and social functioning is well established 3, 4. Most patients with wounds are treated by district nurses in the community, and wound care occupies a large part of the working time of district nurses. Finally, wound care generates costs to the health care system, particularly in terms of the opportunity cost of hospital beds. All these costs are likely to increase over time as the population ages. The Hull audit provides a chance to understand what drives these costs and to focus on opportunities for improvement. We believe that these results are generalisable to other similar populations in the UK and elsewhere.

One of the features of the audit results is the relatively high incidence of non healing wounds. One in four of all wounds had been unhealed for at least 6 months at the point of the audit. Excluding surgical wounds, one in three had been unhealed for at least 6 months and one in five for a year or more. Almost 42% of leg/foot ulcers had not healed in the previous 6 months and 28% had been unhealed for a year or longer. The approximate mean duration of leg/foot ulcers at the point of the audit was 26 weeks.

The problem of non healing highlights the importance of effective diagnosis and appropriate treatment. The audit showed that 26% of wounds that were classified as leg/foot ulcers had no definite diagnosis. Of the 432 leg ulcers, which were classified as venous, 24% had not had a Doppler assessment and 46% of patients with a venous leg ulcer did not receive multilayer high compression. This is not unique to Hull. Many international studies have reported similar results 5, 6, 7.

Wound infection is an important contributor to delayed healing. In the audit, 12·8% of wounds were reported as showing signs of infection, although not all of these wounds may actually have been infected. The rate was highest in surgical/trauma wounds (14·5%) and among hospital patients with wounds (16·2%).

In England, the overall rate of pre‐discharge surgical site infection is 4–5%. Seventy per cent are infections of the skin (as opposed to deep tissues or other structures) and one in four is colonised with methicillin‐resistant Staphylococcus aureus (MRSA) (8). Bearing in mind that most infections (50–70%) are detected after discharge (9), the overall rate of surgical infection nationally may be as high as 12%.

Surgical infections are expensive to treat. The presence of surgical wound infection detected pre‐discharge is estimated to double inpatient costs and increase length of stay by 7–21 days. The cost per patient episode is between £2200 and £6600 10, 11. NHS Reference Costs for skin infections range from £935 to £2845 [minor skin infection (J45) = £935–£1311, average length of stay = 3 days; major skin infection (J41.J42) = £955–£2845, average length of stay = 3–10 days]. The cost of an MRSA infection is significantly higher. One study found inpatient length of stay to be three times longer for patients with MRSA (compared with patients with no infection). The cost of antibiotics alone amounted to £2400 (12).

The cost of pre‐discharge wound infection reinforces the fact that the most important component of wound cost overall is the cost incurred by the relatively small number of patients who are admitted to hospital (or whose discharge is delayed) because of wound complications. After adjustment for non response, less than 16% of patients with wounds in the Hull audit (15·8%) were being treated in hospital, but these patients accounted for between 37% and 49% of total cost (Table 4). Reducing the incidence of wound complications and of delayed healing generally is a key means to reduce the costs of wound care.

Nurse time is also an important component of cost. The estimate here suggests that nurse time accounts for around 33–41% of the total. This is probably an underestimate because it takes no account of the time nurses spend in wound assessment and monitoring or in turning patients at risk of pressure damage. In addition, some part of the additional costs of hospitalisation is actually nurse costs. Nonetheless, expressed in terms of full‐time equivalent staff, the amount of nurse time devoted to patients with wounds is striking. On the basis of the Hull audit, dressing changes alone might have required the equivalent of 88·5 full‐time nursing staff across all sectors. The best way to minimise the demands on nurse time is to heal wounds as quickly as possible and to ensure that dressings are not changed more frequently than necessary.

The cost of dressings and other materials accounts for 17–22% of total cost. This suggests that seeking to reduce wound care costs simply by reducing the cost of dressings is likely to have a limited impact. The results of the audit suggest that ensuring effective and timely diagnosis and appropriate treatment is significantly more likely to affect costs.

The cost estimates here are subject to a wide margin of error, but we believe that they are sufficiently robust to indicate that wound care is a significant call on NHS resources and to highlight that there are real opportunities for costs to be reduced. The total cost estimate is particularly sensitive to assumptions about wound‐attributable costs in the hospital sector. Future work should focus on refining assumptions about key cost drivers: frequency of dressing change, incidence of wound complications and the incidence of wound‐attributable hospital admission and delayed discharge.

We believe that these results are generalisable. Our results highlight the importance of effective diagnosis, appropriate treatment and active measures to avoid the incidence of wound complications which have a major impact on both costs and patient quality of life.

Declaration of interest

None.