The Costs of Caring for Patients in a Tertiary Referral Australian Intensive Care Unit

mRNA-based COVID-19 booster vaccination is highly effective and cost-effective in Australia

BACKGROUND

Australia implemented an mRNA-based booster vaccination strategy against the COVID-19 Omicron variant in November 2021. We aimed to evaluate the effectiveness and cost-effectiveness of the booster strategy over 180 days.

METHODS

We developed a decision-analytic Markov model of COVID-19 to evaluate the cost-effectiveness of a booster strategy (administered 3 months after 2nd dose) in those aged ≥ 16 years, from a healthcare system perspective. The willingness-to-pay threshold was chosen as A$ 50,000.

RESULTS

Compared with 2-doses of COVID-19 vaccines without a booster, Australia's booster strategy would incur an additional cost of A$0.88 billion but save A$1.28 billion in direct medical cost and gain 670 quality-adjusted life years (QALYs) in 180 days of its implementation. This suggested the booster strategy is cost-saving, corresponding to a benefit-cost ratio of 1.45 and a net monetary benefit of A$0.43 billion. The strategy would prevent 1.32 million new infections, 65,170 hospitalisations, 6,927 ICU admissions and 1,348 deaths from COVID-19 in 180 days. Further, a universal booster strategy of having all individuals vaccinated with the booster shot immediately once their eligibility is met would have resulted in a gain of 1,599 QALYs, a net monetary benefit of A$1.46 billion and a benefit-cost ratio of 1.95 in 180 days.

CONCLUSION

The COVID-19 booster strategy implemented in Australia is likely to be effective and cost-effective for the Omicron epidemic. Universal booster vaccination would have further improved its effectiveness and cost-effectiveness.

Health system costs of rheumatic heart disease care in South Africa

BACKGROUND

Rheumatic Heart Disease (RHD) is a disease of poverty that is neglected in developing countries, including South Africa. Lack of adequate evidence regarding the cost of RHD care has hindered national and international actions to prevent RHD related deaths. The objective of this study was to estimate the cost of RHD-related health services in a tertiary hospital in the Western Cape, South Africa.

METHODS

The primary data on service utilisation were collected from a randomly selected sample of 100 patient medical records from the Global Rheumatic Heart Disease Registry (the REMEDY study) - a registry of individuals living with RHD. Patient-level clinical data, including, prices and quantities of medications and laboratory tests, were collected from the main tertiary hospital providing RHD care. All annual costs from a health system perspective were estimated in 2017 (base year) in South African Rand (ZAR) using a combination of ingredients and step-down costing approaches and later converted to United States dollars (USD). Step-down costing was used to estimate provider time costs and all other facility costs such as overheads. A 3% discount rate was also employed in order to allow depreciation and opportunity cost. We aggregated data to estimate the total annual costs and the average annual per-patient cost of RHD and conducted a one-way sensitivity analysis.

RESULTS

The estimated total cost of RHD care at the tertiary hospital was USD 2 million (in 2017 USD) for the year 2017, with surgery costs accounting for 65%. Per-patient, average annual costs were USD 3900. For the subset of costs estimated using the ingredients approach, outpatient medications, and consumables related to cardiac catheterisation and heart valve surgery were the main cost drivers.

CONCLUSIONS

RHD-related healthcare consumes significant tertiary hospital resources in South Africa, with annual per-patient costs higher than many other non-communicable and infectious diseases. This analysis supports the scaling up of primary and secondary prevention programmes at primary health centers in order to reduce future tertiary care costs. The study could also inform resource allocation efforts and provide cost estimates for future studies of intervention cost-effectiveness.

Factors affecting adult intensive care units costs by using the bottom-up and top-down costing methodology in OECD countries: A systematic review

OBJECTIVES

To review the studies, which calculated the total intensive care unit costs and indicated the main cost drivers in the intensive care by using either top-down, bottom-up approach or the combination of them.

RESEARCH METHODOLOGY/DESIGNS

A systematic review of papers published until October 2020 was conducted. Search was performed on PubMed, Medline, Scopus and Science Direct databases.

SETTING

This review i examined costs in adult intensive care units, in countries belonging to the Organisation for Economic Co-operation and Development (OECD) (medical, surgical or general adult , paediatric and neonatal were not included).

MAIN OUTCOME MEASURES

Eighteen articles were included in the review.

RESULTS

Eight of the studies used the top-down costing methodology, six of them used the bottom-up approach and four of them used both of them. The mean total patient cost per day ranged from €200.75 to €4321.91 (all costs are presented in 2020 values for euro). Human resources were identified as the largest proportion of total costs. Length of stay, mechanical ventilation, continuous haemodialysis and severe illness are the main cost drivers of intensive care unit total costs.

CONCLUSION

There are a variety of methods and study designs used to calculate costs of an intensive care unit stay.t It is necessary to evolve standardised costing methods in order to make comparisons and succeed in cost-effective management.

A benefit-cost analysis of different response scenarios to COVID-19: A case study

BACKGROUND

This paper compares the direct benefits to the State of Western Australia from employing a "suppression" policy response to the COVID-19 pandemic rather than a "herd immunity" approach.

METHODS

An S-I-R (susceptible-infectious-resolved) model is used to estimate the likely benefits of a suppression COVID-19 response compared to a herd immunity alternative. Direct impacts of the virus are calculated on the basis of sick leave, hospitalizations, and fatalities, while indirect impacts related to response actions are excluded.

RESULTS

Preliminary modeling indicates that approximately 1700 vulnerable person deaths are likely to have been prevented over 1 year from adopting a suppression response rather than a herd immunity response, and approximately 4500 hospitalizations. These benefits are valued at around AUD4.7 billion. If a do nothing policy had been adopted, the number of people in need of hospitalization is likely to have overwhelmed the hospital system within 50 days of the virus being introduced. Maximum hospital capacity is unlikely to be reached in either a suppression policy or a herd immunity policy.

CONCLUSION

Using early international estimates to represent the negative impact each type of policy response is likely to have on gross state product, results suggest the benefit-cost ratio for the suppression policy is slightly higher than that of the herd immunity policy, but both benefit-cost ratios are less than one.

The incidence and clinical outcomes of postextubation dysphagia in a regional critical care setting

BACKGROUND

Postextubation dysphagia (PED) has been shown to occur in 41% of critically ill patients requiring endotracheal intubation. With one-third of patients with PED experiencing silent aspiration, it is reasonable to anticipate negative health outcomes are likely, although this has not yet been systematically explored in an Australian context.

OBJECTIVES

The aim of the study was to determine the impact of PED, in a regional Australian intensive care unit (ICU), on rates of pneumonia, the length of stay in the ICU and hospital, and healthcare expenditure.

METHODS

This study was conducted as a retrospective cohort analysis, which used administrative healthcare data of patients who received endotracheal intubation for invasive mechanical ventilation. Patients with a tracheostomy or known pre-existing dysphagia were excluded.

RESULTS

A total of 822 patient episodes were identified, of which 7% (n = 58) presented with PED. Half of all patients within the PED cohort (53%) were intubated for fewer than 48 h. Patients with PED had a longer median length of stay in the ICU (5 days versus 3 days, p < 0.001) and were more likely to develop pneumonia (odds ratio = 2.51, 95% confidence interval = 1.28, 4.95) than extubated patients without dysphagia. Median cost per hospital admission for patients with PED was double that for extubated patients without dysphagia (AUD $42,685 versus AUD $20,840, p < 0.001).

CONCLUSIONS

This study highlights that even a short duration of intubation may carry a risk of PED. The presence of PED, regardless of duration of intubation, increased the rates of pneumonia, length of stay in the ICU and hospital, and healthcare expenditure.

Costs of Providing Intensive Care for Adult Non-survivors in a Caribbean Teaching Hospital

Introduction  Intensive Care Unit (ICU) is a resource intense area consuming a vast majority of the hospital's budget. This study aimed to determine the costs of providing critical care to non-survivors in an adult ICU at a tertiary care teaching hospital in the Caribbean. Methods  A chart review of non-survivors over a period of nine months was done in an adult ICU. Admission diagnoses, Simplified Acute Physiology Score (SAPS II) score, daily laboratory investigations, drugs, and all therapeutic interventions including mechanical ventilation were recorded. Activity-based costs were prospectively estimated by data obtained from ICU flowsheets, nursing-activity scores, and various hospital departments. Results A total of 316 days of ICU intervention data were collected from the 39 non-survivors enrolled. The median patient age was 56 years. The median ICU length of stay (LOS) and the median duration of mechanical ventilation were five days. The median SAPS II score was 62. One-third of patients had cardiovascular problems and 28% were surgical patients. The total cost of providing ICU care for the non-survivors was US$ 765,233 with an average cost of US$ 19,621 per patient. Human resources (39%) and consumables (29%) were the highest components of costs. Patients who had a cardiac arrest before admission consumed more resources. A higher SAPS II score predicted a shorter LOS (p=0.01) and lower costs (p=0.03). Conclusions  ICU care for non-survivors consume significantly high resources. Stringent admission protocols and consideration of medical futility at an earlier stage, using prognostic models and clinical criteria may prevent unnecessary interventions and costs.

Attributable cost and extra length of stay of surgical site infection at a Ghanaian teaching hospital

Background

Limited information is available on the financial impact of healthcare associated infections in Sub-Saharan Africa. A prospective case-control study was undertaken at Korle-Bu Teaching Hospital, Ghana, to calculate the cost of surgical site infections (SSI).

Methods

We studied 446 adults undergoing surgery from the surgical department. In all, 40 patients with SSI and 40 control patients without SSI were matched by type of surgery, wound class, ASA, sex and age. The direct and indirect costs to patients were obtained from patients and their carers, daily. The cost of drugs was confirmed with the pharmacy at the department.

Results

The prevalence rate for SSI was 11% of the total 446 cases sampled between June and August 2017. On average patients with SSI who undertook hernia surgery paid approximately US$ 392 more than the matched controls without SSI. The least difference was recorded amongst patients who had thyroid surgery, a difference of US$ 42. The results show that for all surgical procedures, SSI patients report excess length of stay. The additional days range from 1 day for limb amputation, to 16 days for rectal surgery.

Conclusions

In this study, patients with SSI experienced significant prolongation of hospitalisation and increased use of health care costs. In many cases, the indirect costs were much higher than direct costs. These findings support the need to implement preventative interventions for patients hospitalised for various surgical procedures at the Korle Bu Teaching Hospital.

Strategies to Reduce Inappropriate Laboratory Blood Test Orders in Intensive Care Are Effective and Safe: A Before-And-After Quality Improvement Study

Unnecessary pathology tests performed in intensive care units (ICU) might lead to increased costs of care and potential patient harm due to unnecessary phlebotomy. We hypothesised that a multimodal intervention program could result in a safe and effective reduction in the pathology tests ordered in our ICU. We conducted a single-centre pre- and post-study using multimodal interventions to address commonly ordered routine tests. The study was performed during the same six month period (August to February) over three years: 2012 to 2013 (pre-intervention), 2013 to 2014 (intervention) and 2014 to 2015 (post-intervention). Interventions consisted of staff education, designing new pathology forms, consultant-led pathology test ordering and intensive monitoring for a six-month period. The results of the study showed that there was a net savings of over A$213,000 in the intervention period and A$175,000 in the post-intervention period compared to the pre-intervention period. There was a 28% reduction in the tests performed in the intervention period (P <0.0001 compared to pre-intervention period) and 26% in the post-intervention period (P <0.0001 compared to pre-intervention period). There were no ICU or hospital mortality differences between the groups. There were no significant haemoglobin differences between the groups. A multimodal intervention safely reduced pathology test ordering in the ICU, resulting in substantial cost savings.

Economic evaluation of interventions designed to reduce Clostridium difficile infection

INTRODUCTION

Healthcare decision-makers are increasingly expected to balance increasing demand for health services with a finite budget. The role of economic evaluation in healthcare is increasing and this research provides decision-makers with new information about the management of Clostridium difficile infection, from an economic perspective.

METHODS

A model-based economic evaluation was undertaken to identify the most cost-effective healthcare intervention relating to the reduction of Clostridium difficile transmission. Efficacy evidence was synthesised from the literature and was used to inform the effectiveness of both bundled approaches and stand-alone interventions, where appropriate intervention combinations were coupled together. Changes in health outcomes were estimated by combining information about intervention effectiveness and its subsequent impact on quality of life.

RESULTS

A bundled approach of improving hand hygiene and environmental cleaning produces the best combination of increased health benefits and cost-savings. It has the highest mean net monetary benefit when compared to all other interventions. This intervention remains the optimal decision under different clinical circumstances, such as when mortality rate and patient length of stay are increased. Bundled interventions offered the best opportunity for health improvements.

CONCLUSION

These findings provide healthcare decision-makers with novel information about the allocation of scarce resources relating to Clostridium difficile. If investments are not made in interventions that clearly yield gains in health outcomes, the allocation and use of scarce healthcare resources is inappropriate and improvements in health outcomes will be forgone.

Incidence, duration and cost of futile treatment in end-of-life hospital admissions to three Australian public-sector tertiary hospitals: a retrospective multicentre cohort study

OBJECTIVES

To estimate the incidence, duration and cost of futile treatment for end-of-life hospital admissions.

DESIGN

Retrospective multicentre cohort study involving a clinical audit of hospital admissions.

SETTING

Three Australian public-sector tertiary hospitals.

PARTICIPANTS

Adult patients who died while admitted to one of the study hospitals over a 6-month period in 2012.

MAIN OUTCOME MEASURES

Incidences of futile treatment among end-of-life admissions; length of stay in both ward and intensive care settings for the duration that patients received futile treatments; health system costs associated with futile treatments; monetary valuation of bed days associated with futile treatment.

RESULTS

The incidence rate of futile treatment in end-of-life admissions was 12.1% across the three study hospitals (range 6.0%-19.6%). For admissions involving futile treatment, the mean length of stay following the onset of futile treatment was 15 days, with 5.25 of these days in the intensive care unit. The cost associated with futile bed days was estimated to be $AA12.4 million for the three study hospitals using health system costs, and $A988 000 when using a decision maker's willingness to pay for bed days. This was extrapolated to an annual national health system cost of $A153.1 million and a decision maker's willingness to pay of $A12.3 million.

CONCLUSIONS

The incidence rate and cost of futile treatment in end-of-life admissions varied between hospitals. The overall impact was substantial in terms of both the bed days and cost incurred. An increased awareness of these economic costs may generate support for interventions designed to reduce futile treatments. We did not include emotional hardship or pain and suffering, which represent additional costs.

The evolution of Australian intensive care and its related costs: A narrative review

OBJECTIVE

To conduct a narrative review on the evolution of intensive care and the cost of intensive care services in Australia.

REVIEW METHOD

A narrative review using a search of online medical databases and grey literature with keyword verification via Delphi-technique.

DATA SOURCES

Using Medical Subject Headings and keywords (intensive care, critical care, mechanical ventilation, renal replacement therapy, extracorporeal membrane oxygenation, monitoring, staffing, cost, cost analysis) we searched MEDLINE, PubMed, CINAHL, Embase, Google and Google Scholar.

RESULTS

The search yielded 30 articles from which we provide a narrative synthesis on the evolving intensive care practice in relation to key service elements and therapies. For the review of costs, we found five relevant publications and noted significant variation in methods used to cost ICU. Notwithstanding the limitations of the methods used to cost all publications reported staffing as the primary cost driver, representing up to 71% of costs.

CONCLUSION

Intensive care is a highly specialised medical field, which has developed rapidly and plays an increasingly important role in the provision of hospital care. Despite the increasing importance of the specialty and the known resource intensity there is a paucity of data on the cost of providing this service. In Australia, staffing costs consistently represent the majority of costs associated with operating an ICU. This finding should be interpreted cautiously given the variation of methods used to cost ICU services and the limited number of available studies. Developing standardised methods to consistently estimate ICU costs which can be incorporated in research into the cost-effectiveness of alternate practice is an important step to ensuring cost-effective care.

What is a hospital bed day worth? A contingent valuation study of hospital Chief Executive Officers

Background

Decreasing hospital length of stay, and so freeing up hospital beds, represents an important cost saving which is often used in economic evaluations. The savings need to be accurately quantified in order to make optimal health care resource allocation decisions. Traditionally the accounting cost of a bed is used. We argue instead that the economic cost of a bed day is the better value for making resource decisions, and we describe our valuation method and estimations for costing this important resource.

Methods

We performed a contingent valuation using 37 Australian Chief Executive Officers’ (CEOs) willingness to pay (WTP) to release bed days in their hospitals, both generally and using specific cases. We provide a succinct thematic analysis from qualitative interviews post survey completion, which provide insight into the decision making process.

Results

On average CEOs are willing to pay a marginal rate of $216 for a ward bed day and $436 for an Intensive Care Unit (ICU) bed day, with estimates of uncertainty being greater for ICU beds. These estimates are significantly lower (four times for ward beds and seven times for ICU beds) than the traditional accounting costs often used. Key themes to emerge from the interviews include the importance of national funding and targets, and their associated incentive structures, as well as the aversion to discuss bed days as an economic resource.

Conclusions

This study highlights the importance for valuing bed days as an economic resource to inform cost effectiveness models and thus improve hospital decision making and resource allocation. Significantly under or over valuing the resource is very likely to result in sub-optimal decision making. We discuss the importance of recognising the opportunity costs of this resource and highlight areas for future research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2079-5) contains supplementary material, which is available to authorized users.

Variable cost of ICU care, a micro-costing analysis

Intensive care unit (ICU) costs account for a great part of a hospital's expenses. The objective of the present study was to measure the patient-specific cost of ICU treatment, to identify the most important cost drivers in ICU and to examine the role of various contributing factors in cost configuration. A retrospective cost analysis of all ICU patients who were admitted during 2011 in a Greek General, seven-bed ICU and stayed for at least 24hours was performed, by applying bottom-up analysis. Data collected included demographics and the exact cost of every single material used for patients' care. Prices were yielded from the hospital's purchasing costs and from the national price list of the imaging and laboratory tests, which was provided by the Ministry of Health. A total of 138 patients were included. Variable cost per ICU day was €573.18. A substantial cost variation was found in the total costs obtained for individual patients (median: €3443, range: €243.70-€116,355). Medicines were responsible for more than half of the cost and antibiotics accounted for the largest part of it, followed by blood products and cardiovascular drugs. Medical cause of admission, severe illness and increased length of stay, mechanical ventilation and dialysis were the factors associated with cost escalation. ICU variable cost is patient-specific, varies according to each patient's needs and is influenced by several factors. The exact estimation of variable cost is a pre-requisite in order to control ICU expenses.

Cost-Effectiveness of a National Initiative to Improve Hand Hygiene Compliance Using the Outcome of Healthcare Associated Staphylococcus aureus Bacteraemia

BACKGROUND

The objective is to estimate the incremental cost-effectiveness of the Australian National Hand Hygiene Inititiave implemented between 2009 and 2012 using healthcare associated Staphylococcus aureus bacteraemia as the outcome. Baseline comparators are the eight existing state and territory hand hygiene programmes. The setting is the Australian public healthcare system and 1,294,656 admissions from the 50 largest Australian hospitals are included.

METHODS

The design is a cost-effectiveness modelling study using a before and after quasi-experimental design. The primary outcome is cost per life year saved from reduced cases of healthcare associated Staphylococcus aureus bacteraemia, with cost estimated by the annual on-going maintenance costs less the costs saved from fewer infections. Data were harvested from existing sources or were collected prospectively and the time horizon for the model was 12 months, 2011-2012.

FINDINGS

No useable pre-implementation Staphylococcus aureus bacteraemia data were made available from the 11 study hospitals in Victoria or the single hospital in Northern Territory leaving 38 hospitals among six states and territories available for cost-effectiveness analyses. Total annual costs increased by $2,851,475 for a return of 96 years of life giving an incremental cost-effectiveness ratio (ICER) of $29,700 per life year gained. Probabilistic sensitivity analysis revealed a 100% chance the initiative was cost effective in the Australian Capital Territory and Queensland, with ICERs of $1,030 and $8,988 respectively. There was an 81% chance it was cost effective in New South Wales with an ICER of $33,353, a 26% chance for South Australia with an ICER of $64,729 and a 1% chance for Tasmania and Western Australia. The 12 hospitals in Victoria and the Northern Territory incur annual on-going maintenance costs of $1.51M; no information was available to describe cost savings or health benefits.

CONCLUSIONS

The Australian National Hand Hygiene Initiative was cost-effective against an Australian threshold of $42,000 per life year gained. The return on investment varied among the states and territories of Australia.

The quest for a universal definition of polytrauma: a trauma registry-based validation study

BACKGROUND

A pilot validation recommended defining polytrauma as patients with an Abbreviated Injury Scale (AIS) score greater than 2 in at least two Injury Severity Score (ISS) body regions (2 × AIS score > 2). This study aimed to validate this definition on larger data set. We hypothesized that patients defined by the 2 × AIS score > 2 cutoff have worse outcomes and use more resources than those without 2 × AIS score > 2 and that this would therefore be a better definition of polytrauma.

METHODS

Patients injured between 2009 and 2011, with complete documentation of AIS by New South Wales Trauma Registry and 16 years and older were selected. Age and sex were obtained in addition to outcomes of ISS, hospital length of stay (LOS), intensive care unit (ICU) admission, ICU LOS, and mortality. We compared demographic characteristics and outcomes between patients with ISS greater than 15 who did and did not meet the 2 × AIS score > 2 definition. We then undertook regression analyses (logistic regression for binary outcomes [ICU admission and death] and linear regression for hospital and ICU LOS) to compare outcomes for patients with and without 2 × AIS score > 2, adjusting for sex and age categories.

RESULTS

In the adjusted analyses, patients with 2 × AIS score > 2 had twice the odds of being admitted to the ICU compared with those without 2 × AIS score > 2 (odds ratio, 2.5; 95% confidence interval [CI], 2.2-2.8) and 1.7 times the odds of dying (95% CI, 1.4-2.0; p < 0.001 for both models). Patients with 2 × AIS score > 2 also had a mean difference of 1.5 days longer stay in the hospital compared with those without 2 × AIS score > 2 (95% CI, 1.4-1.7) and 1.6 days longer ICU stay (95% CI, 1.4-1.8; p < 0.001 for all models).

CONCLUSION

Patients with 2 × AIS score > 2 had higher mortality, more frequent ICU admissions, and longer hospital and ICU stay than those without 2 × AIS score > 2 and represents a superior definition to the definitions for polytrauma currently in use.

LEVEL OF EVIDENCE

Diagnostic test/ criteria, level III.

Predicting ICU admissions from attempted suicide presentations at an Emergency Department in Central Queensland

BACKGROUND

Emergency medicine physicians and psychiatric staff face a challenging job in risk stratifying patients presenting with suicide attempts to predict which patients need intensive care unit admission, hospital admission or can be discharged with psychiatry follow up.

AIMS

This study aims to analyse patients who were admitted to the intensive care unit or regular ward for suicide attempt, and the methods they employed in a rural Australian base hospital.

METHOD

We conducted a retrospective analysis of patients who presented with suicide attempts to the Rockhampton Base Hospital Emergency Department, Queensland Australia from 1 September 2007 to 31 August 2009. Multivariate logistic regression was undertaken to identify risk factors for ICU and regular ward admission, and predictors of suicide method.

RESULTS

There were 570 patients presenting with suicide attempts, 74 of which were repeat suicide attempts. There was a 10- fold increase in the odds of intensive care unit or ICU admission (CI 1.45-81.9, p=0.02) for patients who presented with drug overdose. Increased age (OR=1.02, 95 per cent CI 1.00-1.03, p=0.05), drug overdose (OR=2.69, 95 per cent CI 1.37-5.29, p=0.004), and previous suicide attempt (OR=1.53, 95 per cent CI 1.03-2.28, p=0.03) were significantly correlated with hospital admission. Male patients (OR=2.76, 95 per cent CI 1.43-5.30, p=0.002) and Aboriginal patients (OR=3.38, 95 per cent CI 1.42-8.05, p=0.006) were more likely to choose hanging as a suicide method.

CONCLUSION

We identified drug overdose as a strong predictor of ICU admission, while age, drug overdose and history of previous suicide attempts predict hospital admission. We recommend reviewing physician practices, especially safe medication, in suicide risk patients. Our study also highlights the need for continued close collaboration by acute care and community mental health providers for quality improvement.

The increased risks of death and extra lengths of hospital and ICU stay from hospital-acquired bloodstream infections: a case-control study

OBJECTIVES

Hospital-acquired bloodstream infections are known to increase the risk of death and prolong hospital stay, but precise estimates of these two important outcomes from well-designed studies are rare, particularly for non-intensive care unit (ICU) patients. We aimed to calculate accurate estimates, which are vital for estimating the economic costs of hospital-acquired bloodstream infections.

DESIGN

Case-control study.

SETTING

9 Australian public hospitals.

PARTICIPANTS

All the patients were admitted between 2005 and 2010.

PRIMARY AND SECONDARY OUTCOME MEASURES

Risk of death and extra length of hospital stay associated with nosocomial infection.

RESULTS

The greatest increase in the risk of death was for a bloodstream infection with methicillin-resistant Staphylococcus aureus (HR=4.6, 95% CI 2.7 to 7.6). This infection also had the longest extra length of stay to discharge in a standard bed (12.8 days, 95% CI 6.2 to 26.1 days). All the eight bloodstream infections increased the length of stay in the ICU, with longer stays for the patients who eventually died (mean increase 0.7-6.0 days) compared with those who were discharged (mean increase: 0.4-3.1 days). The three most common organisms associated with Gram-negative infection were Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia.

CONCLUSIONS

Bloodstream infections are associated with an increased risk of death and longer hospital stay. Avoiding infections could save lives and free up valuable bed days.

Australian quad bike fatalities: what is the economic cost?

OBJECTIVE

To determine the economic costs associated with all quad bike-related fatalities in Australia, 2001 to 2010.

METHODS

A human capital approach to establish the economic costs of quad bike related fatalities to the Australian economy. The model included estimates on loss of earnings due to premature death and direct costs based on coronial records for ambulance, police, hospital, premature funeral, coronial and work safety authority investigation, and death compensation costs. All costs were calculated to 2010 dollars.

RESULTS

The estimated total economic cost associated with quad bike fatalities over this period was $288.1 million, with an average cost for each fatality of $2.3 million. When assessing the average cost of incidents between age cohorts, those aged 25-34 years had the lowest number of fatalities but had the highest average cost ($4.2 million).

CONCLUSIONS

Quad bike fatalities have a significant economic impact on Australian society that is increasing. Implications : Given the high cost to society, interventions to address quad bike fatalities have the potential to be highly cost-effective. Such interventions should focus on design approaches to improve the safety of quad bikes in terms of stability and protection in the event of a rollover. Additionally, relevant policy (e.g. no children under 16 years riding quads, no passengers) and intervention approaches (e.g. training and use of helmets) must also support the design modifications.

Effect of collaborative care on cost variation in an intensive care unit

BACKGROUND

Improving the cost-effectiveness of health care requires an understanding of the genesis of health care costs and in particular the sources of cost variation. Little is known about how multiple physicians, caring collaboratively for patients, contribute to costs.

OBJECTIVE

To explore the effect of collaborative care by physicians on variation in discretionary costs in an intensive care unit (ICU) by determining the contributions of the attending intensivists and ICU fellows.

METHODS

Prospective, observational study using a multivariable model of median discretionary costs for the first day in the ICU, adjusting for confounding variables. Analysis included 3514 patients who spent more than 2 hours in the ICU on the initial day. Impact of the physicians was assessed via variables representing the specific intensivist and ICU fellow responsible on the first ICU day and allowing for interaction terms.

RESULTS

On the initial day, patients spent a median of 10.6 hours (interquartile range, 6.3-16.5) in the ICU, with median discretionary costs of $1343 (interquartile range, $788-2208). There was large variation in adjusted costs attributable to both the intensivists ($359; 95% CI, $244-$474) and the fellows ($756; 95% CI, $550-$965). The interaction terms were not significant (P = .12-.79).

CONCLUSIONS

In an ICU care model with intensivists and subspecialty fellows, both types of physicians contributed significantly to the observed variation in discretionary costs. However, even in the presence of a hierarchical arrangement of clinical responsibilities, the influences on costs of the 2 types of physicians were independent.

Cost-effectiveness of decompressive craniectomy as a lifesaving rescue procedure for patients with severe traumatic brain injury

BACKGROUND

Decompressive craniectomy has been traditionally used as a lifesaving rescue procedure for patients with refractory intracranial hypertension after severe traumatic brain injury (TBI), but its cost-effectiveness remains uncertain.

METHODS

Using data on length of stay in hospital, rehabilitation facility, procedural costs, and Glasgow Outcome Scale (GOS) up to 18 months after surgery, the average total hospital costs per life-year and quality-adjusted life-year (QALY) were calculated for patients who had decompressive craniectomy for TBI between 2004 and 2010 in Western Australia. The Corticosteroid Randomisation After Significant Head Injury prediction model was used to quantify the severity of TBI.

RESULTS

Of the 168 patients who had 18-month follow-up data available after the procedure, 70 (42%) achieved a good outcome (GOS-5), 27 (16%) had moderate disability (GOS-4), 34 (20%) had severe disability (GOS-3), 5 (3%) were in vegetative state (GOS-2), and 32 (19%) died (GOS-1). The hospital costs increased with the severity of TBI and peaked when the predicted risk of an unfavorable outcome was about 80%. The average cost per life-year gained (US$671,000 per life-year) and QALY (US$682,000 per QALY) increased substantially and became much more than the usual acceptable cost-effective limit (US$100,000 per QALY) when the predicted risk of an unfavorable outcome was >80%. Changing different underlying assumptions of the analysis did not change the results significantly.

CONCLUSIONS

Severity of TBI had an important effect on cost-effectiveness of decompressive craniectomy. As a lifesaving procedure, decompressive craniectomy was not cost-effective for patients with extremely severe TBI.

Comparison of physician prediction with 2 prognostic scoring systems in predicting 2-year mortality after intensive care admission: a linked-data cohort study

PURPOSE

Patients who survive an episode of critical illness continue to experience significant mortality after hospital discharge. This study assessed the accuracy of physician prediction of 2-year mortality and compared it with 2 objective prognostic models.

METHODS

Sensitivity (probability of a prediction of death in patients who died within 2 years) and specificity (probability of a prediction of survival in patients who survived at least 2 years) of physicians' 2-year prediction were compared with those from 2 objective prognostic models, Acute Physiology and Chronic Health Evaluation (APACHE) II and Predicted Risk Existing Disease Intensive Care Therapy (PREDICT).

RESULTS

Physician prediction of 2-year mortality was available for 2497 (94.8%) intensive care unit admissions. Specificity was high (85.2%; 95% confidence interval [CI], 83.7-86.4), but sensitivity (65.0%; 95% CI, 61.1-68.8) and positive predictive value (57.4%; 95% CI, 53.6-61.2) were relatively low, suggesting overpessimistic prediction of 2-year mortality. Age, Charlson comorbidity index, and APACHE score were independent risk factors for an inaccurate physician prediction. The diagnostic odds ratio for the physician predictions was at least comparable with the APACHE and PREDICT models, which both had very good discrimination of mortality at 2-year follow-up.

CONCLUSIONS

Physicians tended to overpredict the risk of 2-year mortality of critically ill patients, but accuracy was comparable with 2 objective prognostic models.

Cost-effectiveness of using recombinant activated factor VII as an off-label rescue treatment for critical bleeding requiring massive transfusion

BACKGROUND

Recombinant activated factor VII (rFVIIa) is widely used as an off-label rescue treatment for patients with nonhemophilic critical bleeding.

STUDY DESIGN AND METHODS

Using data from the intensive care unit, transfusion service, and death registry, the long-term survival after using rFVIIa and the associated cost per life-year gained in a consecutive cohort of patients with critical bleeding requiring massive transfusion (≥ 10 red blood cell [RBC] units in 24 hr) were assessed. rFVIIa was only used as a lifesaving treatment when conventional measures had failed.

RESULTS

Of the 353 patients with critical bleeding requiring massive transfusion, 81 (23%) required rFVIIa as a lifesaving rescue treatment. The patients requiring rFVIIa received a greater number of transfusions (number of units: RBCs, 18 vs. 12; fresh-frozen plasma, 16 vs. 10; platelets, 4 vs. 2; p < 0.001) and had a shorter survival time (24 months vs. 33 months; p = 0.002) than those who did not require rFVIIa. The total cost per life-year gained of massive transfusion and incremental cost of rFVIIa as a lifesaving treatment were US$1,148,000 (£711,760; 95% confidence interval [CI], US$825,000-US$1,471,000) and US$736,000 (£456,320; 95% CI, US$527,000-US$945,000), respectively. The incremental costs of rFVIIa increased with severity of illness and transfusion requirement and were greater than the usual acceptable cost-effective limit (<US$100,000 per life-year) for most patients with critical bleeding.

CONCLUSIONS

As a lifesaving treatment for critical bleeding, the incremental cost of rFVIIa was high. Careful patient selection is critical to balance the potential benefits of rFVIIa in an individual patient against the cost to the community.

Economics of ICU organization and management

The intensive care unit (ICU) is a complex system and the economic implications of altering care patterns in the ICU can be difficult to unravel. Few studies have specifically examined the economics of implementing organizational and management changes or acknowledged the many competing economic interests of patient, hospital,payer, and society. With continuously increasing healthcare costs,there is a great need for more studies focused on the optimal organization of the ICU. These studies should not focus solely on reductions in ICU length of stay but should strive to measure the true costs of care within a given healthcare system.

Pharmacoeconomic analysis of voriconazole vs. caspofungin in the empirical antifungal therapy of febrile neutropenia in Australia

In two major clinical trials, voriconazole and caspofungin were recommended as alternatives to liposomal amphotericin B for empirical use in febrile neutropenia. This study investigated the health economic impact of using voriconazole vs. caspofungin in patients with febrile neutropenia. A decision analytic model was developed to measure downstream consequences of empirical antifungal therapy. Clinical outcomes measured were success, breakthrough infection, persistent base-line infection, persistent fever, premature discontinuation and death. Treatment transition probabilities and patterns were directly derived from data in two relevant randomised controlled trials. Resource use was estimated using an expert clinical panel. Cost inputs were obtained from latest Australian sources. The analysis adopted the perspective of the Australian hospital system. The use of caspofungin led to a lower expected mean cost per patient than voriconazole (AU$40,558 vs. AU$41,356), with a net cost saving of AU$798 (1.9%) per patient. Results were most sensitive to the duration of therapy and the alternative therapy used post-discontinuation. In uncertainty analysis, the cost associated with caspofungin is less than that with voriconazole in 65.5% of cases. This is the first economic evaluation of voriconazole vs. caspofungin for empirical therapy. Caspofungin appears to have a higher probability of having cost-savings than voriconazole for empirical therapy. The difference between the two medications does not seem to be statistically significant however.

The critical care costs of the influenza A/H1N1 2009 pandemic in Australia and New Zealand

The aim of this study was to determine the critical care and associated hospital costs for 2009 influenza A/H1N1 patients admitted to intensive care units (ICU) in Australia and New Zealand during the southern hemisphere winter All 762 patients admitted to ICUs in Australian and New Zealand between 1 June and 31 August 2009 with confirmed 2009 H1N1 influenza A were included. Costs were assigned based on ICU and hospital length-of-stay, using data from a single Australian ICU which estimated the daily cost of an ICU bed, along with published costs for a ward bed. Additional costs were assigned for allied health, overheads and extracorporeal membrane oxygenation services. The median (interquartile range) ICU and total hospital costs per patient were AU$35,942 ($10,269 to $82,152) and AU$51,294 ($22,849 to $110,340) respectively, while the mean (standard deviation) ICU and total hospital costs per patient were AU$63,298 ($78,722) and AU$85,395 ($147,457), respectively. A multivariate analysis found death was significantly associated with a reduction in the log of total costs, while the use of mechanical ventilation and ICU admission with viral pneumonitis/acute respiratory distress syndrome or secondary bacterial pneumonia were significantly associated with an increase in the log of total costs. The cost of 2009 H1N1 patients in ICU was significantly higher than the previously published costs for an average ICU admission, and the total cost of treating 2009 H1N1 patients in ICU admitted during winter 2009 was more than $65,000,000.

Cost-effectiveness analysis of anidulafungin versus fluconazole for the treatment of invasive candidiasis

BACKGROUND

Anidulafungin was found to be non-inferior to and possibly more efficacious than fluconazole for treatment of invasive candidiasis (IC) in a major randomized clinical trial (RCT). There are no data comparing the cost-effectiveness between azoles and echinocandins in treating IC. This economic analysis investigated the cost-effectiveness of anidulafungin compared with fluconazole for treatment of IC in an Australian setting.

METHODS

A decision analytic model was constructed to capture downstream consequences of using either agent for treatment of IC. The main outcomes analysed in the model were treatment success and treatment failure (observed and indeterminate). Outcome probabilities and treatment pathways were derived from a published RCT. Resources used were estimated by an expert panel and cost inputs were derived from the latest Australian resources. The analysis was based on an Australian hospital perspective. Sensitivity analyses were conducted using Monte Carlo simulation.

RESULTS

Anidulafungin (AU$74,587) had a higher total cost than fluconazole (AU$60,945) per successfully treated patient, primarily due to its higher acquisition cost. Hospitalization was the main cost driver for both comparators. However, when the rates of mortality in both treatment arms were considered, treatment with anidulafungin was expected to save an additional 0.53 life-years, with an incremental cost-effectiveness ratio (ICER) of AU$25 740 per life-years saved, which was below the implicit ICER threshold value for Australia. The results were robust over a wide range of variables.

CONCLUSIONS

This is the first economic evaluation of anidulafungin versus fluconazole in the treatment of IC in Australia. Anidulafungin appears to be a cost-effective option.

Cost-effectiveness of a central venous catheter care bundle

Background

A bundled approach to central venous catheter care is currently being promoted as an effective way of preventing catheter-related bloodstream infection (CR-BSI). Consumables used in the bundled approach are relatively inexpensive which may lead to the conclusion that the bundle is cost-effective. However, this fails to consider the nontrivial costs of the monitoring and education activities required to implement the bundle, or that alternative strategies are available to prevent CR-BSI. We evaluated the cost-effectiveness of a bundle to prevent CR-BSI in Australian intensive care patients.

Methods and Findings

A Markov decision model was used to evaluate the cost-effectiveness of the bundle relative to remaining with current practice (a non-bundled approach to catheter care and uncoated catheters), or use of antimicrobial catheters. We assumed the bundle reduced relative risk of CR-BSI to 0.34. Given uncertainty about the cost of the bundle, threshold analyses were used to determine the maximum cost at which the bundle remained cost-effective relative to the other approaches to infection control. Sensitivity analyses explored how this threshold alters under different assumptions about the economic value placed on bed-days and health benefits gained by preventing infection. If clinicians are prepared to use antimicrobial catheters, the bundle is cost-effective if national 18-month implementation costs are below $1.1 million. If antimicrobial catheters are not an option the bundle must cost less than $4.3 million. If decision makers are only interested in obtaining cash-savings for the unit, and place no economic value on either the bed-days or the health benefits gained through preventing infection, these cost thresholds are reduced by two-thirds.

Conclusions

A catheter care bundle has the potential to be cost-effective in the Australian intensive care setting. Rather than anticipating cash-savings from this intervention, decision makers must be prepared to invest resources in infection control to see efficiency improvements.

Mortality and cost outcomes of elderly trauma patients admitted to intensive care and the general wards of an Australian tertiary referral hospital

Mortality and cost outcomes of elderly intensive care unit (ICU) trauma patients were characterised in a retrospective cohort study from an Australian tertiary ICU Trauma patients admitted between January 2000 and December 2005 were grouped into three major age categories: aged > or =65 years admitted into ICU (n = 272); aged -65 years admitted into general ward (n = 610) and aged < 65 years admitted into ICU (n = 1617). Hospital mortality predictors were characterised as odds ratios (OR) using logistic regression. The impact of predictor variables on (log) total hospital-stay costs was determined using least squares regression. An alternate treatment-effects regression model estimated the mortality cost-effect as an endogenous variable. Mortality predictors (P < or = 0.0001, comparator: ICU > or = 65 years, ventilated) were: ICU < 65 not-ventilated (OR 0.014); ICU < 65 ventilated (OR 0.090); ICU age > or = 65 not-ventilated (OR 0.061) and ward > or = 65 (OR 0.086); increasing injury severity score and increased Charlson comorbidity index of 1 and 2, compared with zero (OR 2.21 [1.40 to 3.48] and OR 2.57 [1.45 to 4.55]). The raw mean daily ICU and hospital costs in A$ 2005 (US$) for age < 65 and > or = 65 to ICU, and > or = 65 to the ward were; for year 2000: ICU, $2717 (1462) and $2777 (1494); hospital, $1837 (988) and $1590 (855); ward $933 (502); for year 2005: ICU, $3202 (2393) and $3086 (2307); hospital, $1938 (1449) and $1914 (1431); ward $1180 (882). Cost increments were predicted by age < or = 65 and ICU admission, increasing injury severity score, mechanical ventilation, Charlson comorbidity index increments and hospital survival. Mortality cost-effect was estimated at -63% by least squares regression and -82% by treatment-effects regression model. Patient demographic factors, injury severity and its consequences predict both cost and survival in trauma. The cost mortality effect was biased upwards by conventional least squares regression estimation.

Economic impact of caspofungin as compared with liposomal amphotericin B for empirical therapy in febrile neutropenia in Australia

BACKGROUND

In a major clinical trial, caspofungin was as efficacious as liposomal amphotericin B (LAmB) for empirical therapy in febrile neutropenia. The current study sought to evaluate the economic impact of caspofungin as compared with LAmB for febrile neutropenia in Australia.

METHODS

A decision analytic model was developed to capture the downstream consequences of the empirical antifungal therapy. The main outcomes were success, breakthrough infection, persistent baseline infection, persistent fever, premature discontinuation and death. Underlying transition probabilities and treatment patterns were derived directly from trial data. Resource use was estimated using an expert panel. Cost inputs were obtained from the latest Australian representative sources. The perspective adopted was that of the Australian hospital system. Uncertainty and sensitivity analyses were undertaken via Monte Carlo simulation.

RESULTS

Caspofungin was associated with a net cost saving of AU$7245 (12.6%) per patient over LAmB (AU$50 267 versus AU$57 512). A similar trend was observed with cost per success and death prevented (AU$24 169 and AU$7270, respectively). Caspofungin dominated LAmB as it resulted in higher efficacy and lower costs when compared with LAmB. Persistent fever was the main contributing clinical outcome to the therapeutic costs of both antifungals. The results were most sensitive to therapy duration. Monte Carlo simulation suggested a 99.8% chance for LAmB to cost more than caspofungin.

CONCLUSIONS

This is the first economic study to evaluate the place of caspofungin as empirical therapy in Australia. Caspofungin is more cost-beneficial than LAmB, which contradicts the current Australian guidelines of recommending LAmB as the first choice for empirical therapy.

Cost effectiveness of antimicrobial catheters in the intensive care unit: addressing uncertainty in the decision

INTRODUCTION

Some types of antimicrobial-coated central venous catheters (A-CVC) have been shown to be cost effective in preventing catheter-related bloodstream infection (CR-BSI). However, not all types have been evaluated, and there are concerns over the quality and usefulness of these earlier studies. There is uncertainty amongst clinicians over which, if any, A-CVCs to use. We re-evaluated the cost effectiveness of all commercially available A-CVCs for prevention of CR-BSI in adult intensive care unit (ICU) patients.

METHODS

We used a Markov decision model to compare the cost effectiveness of A-CVCs relative to uncoated catheters. Four catheter types were evaluated: minocycline and rifampicin (MR)-coated catheters, silver, platinum and carbon (SPC)-impregnated catheters, and two chlorhexidine and silver sulfadiazine-coated catheters; one coated on the external surface (CH/SSD (ext)) and the other coated on both surfaces (CH/SSD (int/ext)). The incremental cost per quality-adjusted life year gained and the expected net monetary benefits were estimated for each. Uncertainty arising from data estimates, data quality and heterogeneity was explored in sensitivity analyses.

RESULTS

The baseline analysis, with no consideration of uncertainty, indicated all four types of A-CVC were cost-saving relative to uncoated catheters. MR-coated catheters prevented 15 infections per 1,000 catheters and generated the greatest health benefits, 1.6 quality-adjusted life years, and cost savings (AUD $130,289). After considering uncertainty in the current evidence, the MR-coated catheters returned the highest incremental monetary net benefits of AUD $948 per catheter; however there was a 62% probability of error in this conclusion. Although the MR-coated catheters had the highest monetary net benefits across multiple scenarios, the decision was always associated with high uncertainty.

CONCLUSIONS

Current evidence suggests that the cost effectiveness of using A-CVCs within the ICU is highly uncertain. Policies to prevent CR-BSI amongst ICU patients should consider the cost effectiveness of competing interventions in the light of this uncertainty. Decision makers would do well to consider the current gaps in knowledge and the complexity of producing good quality evidence in this area.

[Cost of intensive care in a German hospital: cost-unit accounting based on the InEK matrix]

OBJECTIVE

The aim of this study was to determine the actual cost per intensive care unit (ICU) day in Germany based on routine data from an electronic patient data management system as well as analysis of cost-driving factors. A differentiation between days with and without mechanical ventilation was performed.

METHODS

On the ICU of a German focused-care hospital (896 beds, 12 anesthesiology ICU beds), cost per treatment day was calculated with or without mechanical ventilation from the perspective of the hospital. Costs were derived retrospectively with respect to the period between January and October 2006 by cost-unit accounting based on routine data collected from the ICU patients. Patients with a length of stay of at least 2 days on the ICU were included. Demographic, clinical and economical data were analyzed for patient characterization.

RESULTS

Data of 407 patients (217 male and 190 female) were included in the analysis, of which 159 patients (100 male, 59 female) were completely or partially mechanically ventilated. The mean simplified acute physiology (SAPS) II score at the onset of ICU stay was 28.2. Average cost per ICU day was 1,265 EUR and costs for ICU days with and without mechanical ventilation amounted to 1,426 EUR and 1,145 EUR, respectively. Personnel costs (50%) showed the largest cost share followed by drugs plus medicinal products (18%) and infrastructure (16%).

CONCLUSIONS

For the first time, a cost analysis of intensive care in Germany was performed with routine data based on the matrix of the institute for reimbursement in hospitals (InEK). The results revealed a higher resource use on the ICU than previously expected. The large share of personnel costs on the ICU was evident but is comparable to other medical departments in the hospital. The need for mechanical ventilation increases the daily costs of resources by approximately 25%.

Review of A Large Clinical Series: A Microcosting Study of Intensive Care Unit Stay in the Netherlands

The primary objective of this study was to estimate the actual daily costs of intensive care unit stay using a microcosting methodology. As a secondary objective, the degree of association between daily intensive care unit costs and some patient characteristics was examined. This multicenter, retrospective cost analysis was conducted in the medical-surgical adult intensive care units of 1 university and 2 general hospitals in the Netherlands for 2006, from a hospital perspective. A total of 576 adult patients were included, consuming a total of 2868 nursing days. The mean total costs per intensive care unit day were 1911, with labour (33%) and indirect costs (33%) as the most important cost drivers. An ordinary least squares analysis including age, Nine Equivalent of Nursing Manpower Use score/Therapeutic Intervention Scoring System score, mechanical ventilation, blood products, and renal replacement therapy was able to predict 50% of the daily intensive care unit costs.

A German national prevalence study on the cost of intensive care: an evaluation from 51 intensive care units

Introduction

Intensive care unit (ICU) costs account for up to 20% of a hospital's costs. We aimed to analyse the individual patient-related cost of intensive care at various hospital levels and for different groups of disease.

Methods

Data from 51 ICUs all over Germany (15 primary care hospitals and 14 general care hospitals, 10 maximal care hospitals and 12 focused care hospitals) were collected in an observational, cross-sectional, one-day point prevalence study by two external study physicians (January–October 2003). All ICU patients (length of stay > 24 hours) treated on the study day were included. The reason for admission, severity of illness, surgical/diagnostic procedures, resource consumption, ICU/hospital length of stay, outcome and ICU staffing structure were documented.

Results

Altogether 453 patients were included. ICU (hospital) mortality was 12.1% (15.7%). The reason for admission and the severity of illness differed between the hospital levels of care, with a higher amount of unscheduled surgical procedures and patients needing mechanical ventilation in maximal care hospital and focused care hospital facilities. The mean total costs per day were €791 ± 305 (primary care hospitals, €685 ± 234; general care hospitals, €672 ± 199; focused care hospitals, €816 ± 363; maximal care hospitals, €923 ± 306), with the highest cost in septic patients (€1,090 ± 422). Differences were associated with staffing, the amount of prescribed drugs/blood products and diagnostic procedures.

Conclusion

The reason for admission, the severity of illness and the occurrence of severe sepsis are directly related to the level of ICU cost. A high fraction of costs result from staffing (up to 62%). Specialized and maximum care hospitals treat a higher proportion of the more severely ill and most expensive patients.

A new methodology for assessment of the performance of heartbeat classification systems

Background

The literature presents many different algorithms for classifying heartbeats from ECG signals. The performance of the classifier is normally presented in terms of sensitivity, specificity or other metrics describing the proportion of correct versus incorrect beat classifications. From the clinician's point of view, such metrics are however insufficient to rate the performance of a classifier.

Methods

We propose a new methodology for the presentation of classifier performance, based on Bayesian classification theory. Our proposition lets the investigators report their findings in terms of beat-by-beat comparisons, and defers the role of assessing the utility of the classifier to the statistician. Evaluation of the classifier's utility must be undertaken in conjunction with the set of relative costs applicable to the clinicians' application. Such evaluation produces a metric more tuned to the specific application, whilst preserving the information in the results.

Results

By way of demonstration, we propose a set of costs, based on clinical data from the literature, and examine the results of two published classifiers using our method. We make recommendations for reporting classifier performance, such that this method can be used for subsequent evaluation.

Conclusion

The proportion of misclassified beats contains insufficient information to fully evaluate a classifier. Performance reports should include a table of beat-by-beat comparisons, showing not-only the number of misclassifications, but also the identity of the classes involved in each inaccurate classification.

Health technology assessment in critical care

BACKGROUND

Heath technology assessments (HTAs) evaluate the benefits and costs of devices for monitoring and therapy (and their associated requirements for human resources) which contribute to the high expense associated with ICU admission.

DISCUSSION

Given the limited resources available for health care and increasing demands, funds spent inefficiently or unnecessarily on technologies in the ICU may threaten the sustainability of the health care system or prevent other potentially cost-effective devices from being introduced into clinical care. We discuss the factors impeding the conducting of HTAs in the ICU and suggest strategies for change.

CONCLUSIONS

Despite the need for HTAs of ICU devices only few have been conducted. They should be undertaken more frequently, and their results used to influence clinical practice and hospital and regional-level policy decisions.

New models for old questions: generalized linear models for cost prediction

BACKGROUND

Generalized linear models (GLMs) have recently been introduced into cost data analysis. GLMs, transformations of the linear regression model, are characterized by a particular response distribution from one of the exponential family of distributions and monotonic link function which relates the response mean to a scale on which additive model effects operate.

OBJECTIVES

This study compared GLMs and ordinary least squares regression (OLS) in predicting individual patient costs in adult intensive care units (ICUs) and sought to define the utility of the inverse Gaussian distribution family within GLMs.

METHODS

A prospective 'ground-up' utilization costing study was performed in three adult university associated ICUs, enrolling consecutive ICU admissions over a 6-month period in 1991. ICU utilization, patient demographic and ICU admission day data were recorded by dedicated data collectors. Model performance was assessed by prediction error [mean absolute error (MAE), root mean squared error (RMSE)] and residual analysis.

RESULTS

The cohort, 1098 patients surviving ICU, was of mean (SD) age 56 (19.5) years and 41% female. Patient costs per ICU episode (1991 A$) were A$6311 (9689), with range A$106 to A$95602. Prediction error for mean costs was minimal (MAE 4780; RMSE 8965) with OLS using heteroscedastic retransformation of log costs and GLM with Gaussian family and log link (MAE 4798; RMSE 8907). Residual analysis suggested optimal overall performance for the above two models and a GLM with inverse Gaussian family and log link.

CONCLUSIONS

Traditional cost models of OLS with (log) cost transformation may be supplemented by appropriately specified GLM which more closely model the error structure.

Cost evaluation in the intensive care units of Trinidad applying the cost-blocks method - an international comparison

This study evaluated the costs of intensive care in Trinidad applying the cost-blocks method. Data regarding demographics, severity of illness, therapeutic interventions and length of stay were prospectively recorded for 111 patients admitted to four intensive care units during a 3-month period. Annual costs, cost per admission, cost per patient-day and cost per therapeutic intervention score point were derived. The cost-block for staff, especially medical staff, was the largest proportion of the expenditure. Process of care and outcome were comparable, whereas costs were lower than the developed countries. The median cost per intensive care unit bed per year and cost per patient per day in Trinidad were 133,117 pounds and 366 pounds, respectively, in comparison with 265,163 pounds and 904 pounds in the UK. The cost-blocks method is a useful framework for evaluating the costs of intensive care and for comparing costs between countries.