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Variation in expenditure on intensive care patients treated in university versus non-university hospitalsJoanne E Dean BA (Hons) Research Associate Medical Economics
and Research Centre, Sheffield (MERCS) Intensive Care Unit Royal
Hallamshire Hospital Glossop Road Sheffield S10 2JF United Kingdom
BACKGROUND TO STUDYIntensive care is regarded as an expensive specialty throughout the developed world [1]. This is due to the fact that the sickest patients in the hospital are treated in the Intensive Care Unit (ICU). ICU patients require higher levels of care than non-ICU patients do; they consume more resources (e.g. drugs and fluids) and require superior medical technology and interventions (e.g. mechanical ventilation), than patients located on the general ward. An ICU is defined by the Department of Health as treating "Patients requiring advanced respiratory support alone or basic respiratory support together with support of at least two organ systems. This level includes all complex patients requiring support for multi-organ failure"[2]. Staff input is greatest on the ICU, with at least one nurse allocated to each bed on the unit, compared with general ward staffing levels of only one or two nurses per ward. These factors all contribute to the expensive nature of intensive care. Attempts have been made to collect accurate cost data relating to intensive care, with the bulk of the research originating from the United States (US). However, most American cost data studies report charges as opposed to costs, and no data tends to be comparable due to differences in the methods used to obtain the data, and the inclusion of contrasting cost components in the different studies. The launch of the cost block programme on a national level in the UK in 1999 has signified an end to the lack of standardised cost data relating to intensive care. Collecting cost block data has enabled a database of comparable intensive care unit costs to be established, as well as detailed information pertaining to the characteristics of each hospital. This information is then used to identify expenditure relating to average costs per patient, average costs per patient day and the average cost per bed for ICUs in the UK. Data for the cost block programme is collected using a standard questionnaire, that involves participants collecting annual retrospective cost data from three areas of resource use, namely staff, consumables and clinical support services. These three areas of resource use are known as cost blocks, and make up the key components of a method developed to capture and identify the costs of intensive care at an individual hospital level. Results obtained from different hospitals are comparable due to the standardisation of the method used to collect the data [3]. Two pilot studies were undertaken prior to the national launch of the programme, both of which highlighted considerable variation in the total running cost of an ICU. One of the factors explaining a large proportion of the observed variation in expenditure between units was university hospital status. The majority of cost components identified, were significantly more expensive in ICUs located in a hospital defined as a university hospital [4]. The purpose of this study was to examine whether intensive care units based in university hospitals incur significantly higher levels of expenditure, when compared to intensive care units based in non-university hospitals. This was established by using cost block data collected for the financial year 1998-1999 from 51 ICUs geographically represented by all NHS Executive Regions, with the exception of Scotland. This study attempted to highlight which particular cost drivers were responsible for any observed variation in expenditure, and to ascertain the impact that university hospital status had on the expenditure of intensive care.
LITERATURE REVIEWCommon perceptions of university hospitals are that they treat more severely ill patients, who require more medical interventions [5] [6]. This results in a need for higher quantities of specially trained medical staff than are necessitated in non-university hospitals. As a consequence of this, it is commonly believed that university hospitals incur more costs than non-university hospitals. Some studies have stated that the cost per case in university hospitals is more than 60% [7] higher than in non-university hospitals, whilst others assert that the average cost difference between university and non-university hospitals is nearer 20% [8]. While there may be differences in the reported costs of university and non-university hospitals, all agree that university hospitals are more expensive than non-university hospitals.
Accounting for expenditure within university hospitals Accounting for different levels of expenditure within hospitals is a main concern within the NHS. Finite resources coupled with increasing demands for healthcare lead to calls for cost effectiveness in the healthcare environment. As yet, university hospitals have not been able to completely account for their heightened levels of expenditure. The majority of studies concentrate only on case-mix, where the bulk of the research shows that university hospitals treat a more severely ill group of patients than non-university hospitals [6] [5]. However, some university hospitals have been shown to have higher costs even when case mix is held constant [9]. A study by Richards et al found few differences between university and non-university hospitals, when assessing the case-mix of patients treated, but found evidence for higher levels of resource utilisation at university hospitals [10]. No comparable studies have been undertaken linking case-mix and expenditure, whilst any costing methods previously employed, used different combinations of cost components, therefore limiting data comparisons.
Standardisation of costs in the critical care environment One area of healthcare where standardised costs have been collected in the United Kingdom (UK) is in the critical care environment. The Cost Block Method developed by Edbrooke et al [3] was launched nationally in the UK in 1999 after being extensively piloted for five years. The Cost Block Method collects retrospective cost data relating to critical care from the areas of staff, consumables and clinical support services for the purposes of bench marking and inter unit comparisons. It is appropriate that a method for costing should have been developed initially for use within the critical care environment, due its expensive nature. In 1999 the cost per year of critical care to the NHS was estimated at £675 million, with a predicted increase of 5% per annum [11]. The cost difference between ICU and non-ICU cost per day has been gauged between $1200 and $1300 for surviving patients [1]. Whilst in the UK, the cost of care in the Intensive Care Unit is purported to be four times the cost of general ward care [3].
Critical care and university hospital expenditure If we couple the expensive nature of critical care with the supposed extra cost of university hospitals, then one would expect to see a significant difference when comparing the cost of critical care in a university hospital, to the cost of critical care in a non-university hospital. Few studies have been published that hypothesise whether there is any difference in expenditure between critical care in university and non-university hospitals. The majority of published studies focus on case-mix and severity of illness, with no comparable studies available that focus on examining different levels of expenditure. Substantial evidence highlighting the additional workload of the university hospital has been undertaken, especially in relation to case-mix. University hospitals are found to provide more beds and physicians [6], and also admit nearly twice the number of patients admitted by non-university ICUs. In the same study, mean observed length of stay at university ICUs was 5.2 days compared to 4.4 days at non-university hospitals. It is also believed that university hospitals use more aggressive treatment regimes [5]. When looking at the incidence of therapy withdrawal in university and non-university hospitals, it is apparent that patients located in university hospital ICUs are more likely to have treatment withdrawn. Whereas, patients in non-university hospital ICUs are more likely to have the treatment withheld in the first instance (11.9% Vs 3.8%) [13]. If university hospitals are more likely to treat patients, that would otherwise be denied treatment in a non-university hospital, then this may contribute to increased levels of cost in university hospitals.
Critical Care National Cost Block Programme As previously mentioned, the only standardised cost data relating to critical care is data obtained by using the Cost Block Method. Results from the second pilot study using data collected from 21 hospitals show there is evidence of cost variation within critical care. For example the average cost per patient day ranged between £615 and £1250 [4]. Regression analysis was used to attempt to explain any variation that occurred within the cost components. Presence of a university hospital was found to be significant (p<0.05) in explaining variation in the costs of drugs and fluids, disposable equipment, nursing staff and consultant staff.
Aims and objectives The primary aims of this study were to measure the extent to which a variation in expenditure existed between ICUs located in university hospitals and ICUs in non-university hospitals, and to identify those factors attributable to this variation. This was achieved by:
METHODSData was collected from 51 critical care units for the financial year 1998-1999 using 'Cost Block' methodology. The cost block programme collected annual retrospective cost data using a standard questionnaire from three areas of resource use, namely staff, clinical support services and consumables. Staff was defined as " all personnel employed fully or partly within the ICU, both permanent and bank staff. The costs included all on-costs such as national insurance, superannuation contributions, sick leave, maternity leave and annual leave." [4] Clinical support services was defined as "services directly related to patient care but not supplied by the ICU" [4]. Consumables was defined as "the use of drugs, fluids, nutrition, blood and blood products and disposables used within the ICU." [4] Each of the three areas of resource use or 'Cost Blocks' comprised numerous individual cost components. Costs collected in the staff cost block included Consultant medical staff "The costs of consultant medical staff were calculated based on the number of fixed an flexible sessions worked in the ICU. Fixed sessions were those with clinical commitments. The cost per session was calculated from the salaried costs that included merit awards (where applicable) and all on-costs. A formula was used to determine the total cost which was (the total number of fixed sessions plus 50% of the total number of flexible sessions) multiplied by the cost per session." [4] Other medical staff (junior medical staff) "The total cost of other medical staff (senior house officers, registrars, senior registrars and staff grade medical staff) was calculated by multiplying the number of hours worked in the ICU (standard and additional duty hours) by the mid point of the pay scale for each level of grade. The mid point of the pay scale assumed that staff were available for 42 weeks of the year, they worked 40 hours per week and 24 additional duty hours." [4] Nursing staff (including established bank and agency nursing staff) "The cost of nurses included those on sick, study and or maternity/paternity leave. The cost of nurses undergoing training was also included. The annual cost of bank and agency staff was added to the cost of established nursing staff." [4] Technical staff "The annual cost of technical staff reflected the proportion of time they spent on the ICU." [4] Administrative staff (including research, audit, management, information technology and administration staff). The annual cost of administrative reflected the proportion of time they spent on the ICU. The costs of
were collected within the clinical support services cost block, whilst the consumables cost block consists of
Also collected within the cost block programme from each participating unit, was information relating to the characteristics of the unit i.e.
Units were defined as an ICU if they treated "Patients requiring advanced respiratory support alone or basic respiratory support together with support of at least two organ systems. This level includes all complex patients requiring support for multi-organ failure"[2]. High Dependency Units (HDUs) were classified as treating "Patients requiring more detailed observation or intervention including support for a single failing organ system or post-operative care, and those 'stepping down' from higher levels of care" [2].
Geographical distribution of participating units Units were recruited by their willingness to participate, and participants were located in all NHS Executive Regions excluding Scotland and the Republic of Ireland. The geographical distribution of units is described in table 1 below.
Table 1: Geographical distribution of units
The numbers of participating hospitals that are defined as having university hospital status was also collected in the Cost Block questionnaire. Within the sample of 51 units, 12 were recognised as university hospitals, while the remaining 39 were classified as non-university hospitals (see figure 1). This is thought to be proportional to the distribution of university and non-university hospitals across the UK, as it is estimated that approximately a quarter of all hospitals are classified as university hospitals.
Defining university hospitals University hospitals were defined within the cost block programme as hospitals with an affiliated medical school. However, it was necessary to validate the definition of university hospitals used in this study, by cross-referencing the numbers of university hospitals recognised by the cost block programme, with data from the Department of Health. This was achieved using NHS Executive Performance Indicators obtained via the Department of Health website. The performance indicators categorised all hospitals located in NHS Executive Regions as one of five categories. By matching the hospitals from the participating sample for this study with the NHS Executive Performance Indicators, we were able to identify whether the same hospitals were classified as university hospitals by both studies. The units in the sample were categorised as Acute Teaching Hospital, Very Large Acute Hospital, Large Acute Hospital, Small/Medium Acute Hospital, Multi Service Hospital and Acute Specialist Hospital. Out of the 12 hospitals identified as university hospitals by the cost block programme, 10 of these were recognised as Acute Teaching hospitals by the Department of Health. One of the remaining two hospitals not recognised as a university hospital did not appear in the Department of Health's sample, due to its location in Ireland. However, there is no explanation for the remaining hospital that is classified as a university hospital by the cost block programme methodology and not by the NHS Executive.
Data validation 10% of the hospitals in the sample underwent an audit of their data, to ascertain levels of data accuracy, uniformity and completeness. This was conducted at the site of data collection for each hospital, and required each hospital to provide source documents for each data item. Once data had been queried and thoroughly checked, the data was entered into the Statistical Package for Social Scientists (SPSS). For each data item in the three cost blocks, a cost per patient and a cost per patient day was calculated. A cost per bed was also calculated for all components in the staff cost block. Histograms of the data, supported with the results of a Shapiro-Wilk test determined whether the distribution of the data on expenditure could best be described using parametric or non-parametric statistical techniques.
RESULTSThe data collected using the cost block questionnaire, can be used to not only to calculate the average total cost of an intensive care unit, but also to calculate an average cost per bed, an average cost per patient and an average cost per patient day. The average (mean) total cost (sum of all cost blocks) for all units participating in the Cost Block Programme was £1,649,550 for financial year 1998-1999. However total expenditure on all cost blocks ranged between £927,244.88 for minimum expenditure to £3,807,528 for maximum expenditure (see Figure 2). Therefore it is evident that some degree of variation in expenditure on critical care in the UK does exist. By using data collected within the cost block programme, it was possible to determine whether certain hospital factors are responsible for any observed variation in expenditure, for example, number of patients, number of patient days or the number of beds. Previously published studies using cost block data have demonstrated a statistical association between these variables and total expenditure on critical care [3] Variation in total expenditure incurred by critical care units could possibly be explained by a number of factors, including:
One factor that is thought to be significant in explaining any observed difference in expenditure, both in critical care units and throughout the entire hospital, is whether the hospital is defined as a teaching or university hospital. For this study, therefore, the total annual cost for university and non-university hospitals has been calculated. Non-university hospitals spend on average £1,428,982 per year on critical care, whilst university hospitals spend £2,366,397. (Figure 3: Total expenditure on critical care for all participating units - A comparison of university and non-university hospitals) When looking at the distribution of total expenditure, it was evident that all of the hospitals classified as university hospitals spend significantly (p<0.001) more than the non-university hospitals. Three university hospitals were shown to have significantly higher expenditure than all other participating units. (Figure 4: A bar chart to show total expenditure in university and non-university hospitals) One reason cited in the literature that may explain increased expenditure on critical care in university hospitals is that university hospitals have a greater number of beds than non-university hospitals [6]. This was found to be the case in the participating sample for this study, as university hospitals had on average 8.3 beds, whilst non-university hospitals were found to have an average of 5.9 beds for financial year 1998-1999. When the total cost was apportioned by the number of beds, this was found to be significant in explaining variation in expenditure between university and non-university hospitals (p<0.001). Table 2: Average cost per bed for critical care units located in university and non-university hospitals
Further published research cites the number of admissions as a having an influential bearing on expenditure. University hospitals were found to admit more patients in this study, admitting on average 531 patients, whilst non-university hospitals admitted an average of 400 patients over the same time period. However, when total cost was apportioned by the number of patients, there was no significant difference in expenditure between university and non-university hospitals. Table 3: Average cost per patient for critical care units located in university and non-university hospitals
University hospitals were also found to have a higher number of patient days than non-university hospitals. University hospitals incurred on average 2443 patient days over the study period, compared to non-university hospitals incurring on average 1616 patient days. Yet when total cost was apportioned by the number of patient days to form an average cost per patient day, there was no significant difference in expenditure between university and non-university hospitals. Table 4: Average cost per patient day for critical care units located in university and non-university hospitals
The cost block programme collected cost data relating to three areas of resource use, (staff, consumables and clinical support services). Each area of resource use or 'cost block' consists of a variety of components. When looking at the individual components of each cost block, some components do incur significantly more expenditure in university hospitals when compared to non-university hospitals. This is despite no significant difference in total cost per patient, total cost per patient day and total cost per bed being found between university and non-university hospitals. The majority of these cost components are located in the staff and consumables cost blocks. Within the consumables cost block, areas of significance included the cost per patient day of drugs and fluids, the cost per patient day of disposable equipment and the cost per patient day of nutritional products. In the staff cost block, technical staff, bank and agency nursing staff and administrative staff were found to be more frequently used in university hospitals, therefore incurring greater levels of expenditure than in non-university hospitals.
Prior to the national launch of the cost block programme in 1999, data was collected from six areas of resource use. Pilot studies of cost block data all included data collected from six cost blocks [3]. However, data is now only collected from three cost blocks. The three defunct cost blocks are estates, capital equipment and non-clinical support services. The estates cost block comprised of
Data relating to the estates, capital equipment and non-clinical support services was found to be extremely difficult to collect. As these three cost blocks were found to represent only 15% of the total cost, the critical care national working group on costing decided that these cost blocks should no longer be included within the cost block programme, hence no data has been collected on the above mentioned data items [4].
DISCUSSIONThe objective of this research was to ascertain whether any difference in expenditure existed between ICUs located in university hospitals when compared to ICUs located in non-university hospitals. The bulk of the literature reviewed states that university hospitals incur more expenditure than non-university hospitals. The primary reason given for the increased expenditure in university hospitals relates to case-mix, with nearly all asserting that university hospitals treat a more heterogeneous and severely ill group of patients [5] [6], and as a consequence of this incur more costs. Using the cost block method to provide data for this study presents me with several problems, including a lack of access to case-mix data. The cost block method does not yet incorporate case mix within its data collection components, therefore it is impossible to incorporate any measure of case mix or severity of illness within this particular study, due to information and resources available. However, studying the impact of case mix on expenditure in critical care may warrant further investigation in a study of a larger nature. One further limitation of using the cost block method is that it does not capture the variation between individual patient costs. The cost block methodology uses a 'top down' approach to costing, which apportions the annual total cost data from each participating ICU by the throughput and size of the unit, to calculate average unit costs [3]. To ascertain individual patient costs can only be achieved using a 'bottom up' approach to costing. Bottom up costing collects detailed expenditure on each patient admitted to the ICU, thereby creating a cost per individual patient. This method of data collection is extremely time consuming and laborious, and given that we are assessing whether total expenditure varies in ICUs located in a university or non-university hospital, it was deemed unnecessary to obtain individual patient data. Further reasons cited in the literature that may explain why university hospitals are more expensive, relate to the size and throughput of the unit. University hospitals were shown to have more beds and therefore admit more patients. Results from the cost block data show that ICUs in university hospitals incur more costs than ICUs in non-university hospitals. Yet the results also show that this increase in expenditure is not statistically significant when total cost is broken down into an average cost per bed, an average cost per patient and an average cost per patient day. Results from the cost block programme support some factors from the literature as both agree that university hospitals have more beds and are therefore bigger. However the lack of difference in expenditure found between university and non-university hospitals in the cost block data when costs are broken down by the number of beds, the number of patients and the number of patient days, leaves the data open to interpretation. Either there is no difference in case mix as there is very little difference in cost, or case mix has very little bearing on cost, and only the size of the unit is responsible for any observed difference in expenditure between university and non-university hospitals. Both the above conclusions are the very antithesis of conclusions drawn by previous studies. One reason why the results from the cost block programme are so contrasting may lie in the size of the sample used for this study. No sampling techniques were required when designing the study, as units were recruited by their willingness to take part. The optimum sample size for the study undertaken is still unknown. When comparing the number of units participating to the total population available, only 16% of the total population were included in this study. Therefore, it may be that too small a sample has been used, to obtain results that are reflective of all units. In 1993 Pocock stated that "one common failure of research design is in using inadequate sampling techniques (which lead to sample bias and poor external validity) and inadequate sample sizes, which prevent investigators drawing a reliable conclusion" [14]. It may be that it is inappropriate to make generalisable conclusions about this study, as with a small sample, there is less chances of observing differences between ICUs located in university and non-university hospitals. Pocock concurs that "a small sample, however random, in selection is less likely to be accurate in its representation of the total population than a larger sample' [14]. To obtain reliable results in a study of this nature, we would need not only a larger sample, but also a more representative sample that includes more of the larger university hospitals. This is because the sample for this study could be affected by response bias. As units are only recruited by their willingness to take part, units that currently participate may be those units that feel they will perform best in terms of cost. University hospitals are thought to be more expensive, therefore they may be less willing to take part than less expensive units. The majority of university hospitals included in the sample may be the smallest and most cheaply run university hospitals. The three university hospitals that have extremely high costs compared to all the other hospitals participating in the study (see figure 2) may be a more accurate representation of university hospital costs in the UK. However, this will only be determined by repeating the study with a larger and more representative sample of units.
CONCLUSIONS AND RECOMMENDATIONSAn array of literature suggests that university hospitals incur additional costs. Yet no study has been able to give a full account as to why university hospitals are more expensive than non-university hospitals. This study attempts to give further insight into both the costs of university hospitals and the costs of intensive care, with a view to explaining previously unexplained cost variation. This objective has been hindered by the failure to obtain a large enough sample population. However, a significant difference in total expenditure between university and non-university hospitals has been observed. Further research needs to be undertaken in this area, as there are still many unanswered questions relating to why university hospitals incur more costs than non-university hospitals, particularly within intensive care. It would be especially valuable to assess the financial implications of case mix on intensive care units located in university and non-university hospitals. In the future, it is hoped that cost block data will be linked to measures of case mix, thereby making it possible to assess whether the literature reviewed was correct in its assertion that case mix is responsible for the increased costs of university hospitals. Until this has been achieved, there is little research of any value studying the impact of university hospital status on critical care units in the United Kingdom.
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