Many guidelines now recommend screening some patients on admission for carriage of CPE. However, very few cost-effectiveness analyses have been performed. A Canadian group have just published a modelling study with a tantalising conclusion: universal admission screening for CPE is likely to be cost-effective, and may even be cost-saving!
A very enjoyable few days in Edinburgh this week for the Federation of Infection Societies / Healthcare Infections Society (FIS/HIS) meeting. Some reflections follow…
Shortly after the PHE Toolkit was published, I blogged some crude sums to size the burden of CRE admission screening a la Toolkit. I’m pleased to report that colleagues at Imperial have done a much better job of this, published in a letter in the Journal of Infection. The study provides some evidence that the recommendation in the PHE CRE Toolkit to perform pre-emptive isolation of suspected carriers whilst obtaining three negative screens is simply not feasible. The team then compare an alternate strategy – of applying the Tookit triggers to admissions to high risk specialties only (intensive care, nephrology, cardiothoracic surgery, neurosurgery and oncology).
I had the opportunity to ask the audience how they were detecting CRE in their diagnostic clinical labs during a talk last week. It was an audience of around 50 laboratory and clinical folk, mainly from the UK but a few from continental Europe. And here’s what I found:
I was a little surprised that more labs have switched to using chromogeneic agar plates than use non-chorogeneic agar plates. In the case of our lab in London, we are currently using non-chromogenic media for clinical samples, but in the process of evaluating chromogenic media. Although the purchase costs of chromogenic media are higher, they are more sensitive and substantially reduce the amount of time required to confirm a negative or positive culture, so I suspect they actually work out cheaper when you factor in labour costs.
I was not surprised that so few labs are using PCR. The costs are considerably higher but turnaround time is faster and they are more sensitive. There are now a number of PCRs on the market for the detect of CRE direct from rectal swabs (e.g. Checkpoints and Cepheid). We are currently in the process of evaluating the Checkpoints assay and after sharing our preliminary data, this was the feeling in the room about using PCR to detect CRE:
I think I’ll leave it there for now…
The recent PHE CPE toolkit advocates implementing targeted screening and isolation of carriers. Reading the guidelines in a little more detail, the ‘triggers’ for screening a patient for CPE are, in the last 12 months: (a) an inpatient in a hospital abroad or (b) an inpatient in a UK hospital which has problems with spread of CPE (if known) or (c) a ‘previously’ positive case. Patients who screen positive should be placed in contact isolation; patients who screen negative should be placed in contact isolation until a further two consecutive negative screens have been taken. It’s important to note that the negative screens must be at least 48 hours apart. So, for patient who turns out to be negative will be in contact isolation for around 6 days (screens collection on days 0, 2 and 4, and a further day for the final negative screen result).
The number of patients who will meet the trigger for screening is currently unknown, but I have heard whispers of 25-50% of all admissions. This will place a considerable burden on already over-stretched isolation facilities, and bear substantial cost implications.
Single rooms in the NHS are already in very short supply. Indeed, recent press and commentary highlights the implications of running out of single rooms: patients shunted around “like parcels” in the middle of the night to relieve bed pressures.
Now, you could argue that patients who screen negative for CPE but are awaiting their confirmatory negative screens do not need to be isolated in a single room; they can be isolated in a bay. But if 25-50% of patients suddenly begin contact precautions, you’d quickly run into problems. Patients on contact precautions take longer to care for, and tend to get less attention than other patients resulting in more adverse events, as illustrated by a couple of recent Controversies blogs. Also, I fear you may begin to see ‘isolation fatigue’, where the procedure loses its impact if it has to be applied so broadly. And then there’s the cost. A recent US study calculated that contact precautions cost around £23 ($35) per patient day (not including the cost of disposal for all that additional waste!). If 25% of the 100,000 patients admitted to a London hospital Trust met the trigger for CPE screening and turned out to be negative, the price tag for isolation alone would be pushing £3.5m.
I support the PHE guidelines and agree that we need to “search and destroy” CPE above all else before it becomes endemic. However, are they feasible to implement in their current form?
Image: ‘Swabs’ by Frank Carey.
“Healthcare-Associated Infections” (HAIs)* increase morbidity, mortality and length of hospital stay as well as healthcare costs for the patients, their families and healthcare systems.1 They also lead to long-term disability and increased resistance of microorganisms to antimicrobials. Various studies have attempted to estimate the burden of HAIs. In this context, I came across two recent papers2,3 estimating the cost of HAIs in US acute care hospitals, which prompted me to re-visit the excellent WHO report on the burden on HAIs around the world.1
The WHO report explores the burden of HAIs not only in the high-income countries, where most reported burden estimates come from, but also in low- and middle-income countries, where little data are available. The report indicates that of every 100 hospitalised patients at any given time, 7 in developed and 10 in developing countries will acquired at least one HAI. The prevalence of HAIs in Europe is around 7.1% with more than 4 million patients affected by approximately 4.5 million episodes of HAIs annually and leading to 16 million extra-days of hospital stay, 37,000 attributable deaths and contributing to an additional 110,000. In the US around 1.7 million patients are affected by HAIs annually with a prevalence of 4.5% and accounting for 99,000 deaths. Limited data are available from low and middle-income countries but the prevalence of HAIs in these countries is estimated to be between 5.7 and 19.1%. Increased length of hospital stay associated with HAIs in developing countries range between 5-29.5 days and excess mortality due to these infections in adult patients in Latin America, Asia, Africa were 18.5%, 23.6%, and 29.3%, for CAUTI, CR-BSI, and VAP, respectively.1
HAIs have a huge economic burden. In the WHO report and according to a report from the ECDC,4 these infections account for approximately €7 billion per year in Europe, considering direct costs only. For instance, additional associated costs of a CR-BSI episode in Europe ranged from €4,200 to €13,030, representing annual costs to healthcare systems of €54 million in the United Kingdom and €130 million in France.1 Limited data on the financial cost of HAIs in low- and middle-income countries is available. Reports from Mexican ICUs estimated the overall average cost of a HAIs episode at $12,155 with an excess cost of $11,591 per case of CR-BSI.1 In several ICUs in Argentina, the overall extra cost estimates for CR-BSI and healthcare-associated pneumonia averaged $4,888 and $2,255 per case, respectively.1
In the US, the annual economic impact of HAIs was approximately $6.5 billion in 2004.5 Recently Zimlichman and colleagues2 conducted a systematic review of the literature for the years 1986 through 2013 for an updated estimate of costs associated with the most significant and targetable HAIs in the US. These were CLABSI, VAP, SSI, CR-UTI, and C. difficile infection (CDI). On a pair case basis, CLABSI were found to be the most costly at $45,814 (95% CI, $30,919-$65,245), followed by VAP at $40,144 (95% CI,$36,286-$44,220), SSI at $20,785 (95% CI, $18,902-$22,667), CDI at $11,285 (95% CI, $9,118-$13,574), and CR-UTI at $896 (95% CI, $603-$1,189). Based on 2009 data where approximately 34.7 million adults received inpatient care in US hospitals (totaling 165 million patient days), the total annual cost of the 5 infections was $9.8 billion (95% CI, $ 8.3-11.5 billion) with SSI and CDI being the most frequent (36% and 30% respectively).
Figure: The prevalence and direct cost of HAI in Europe1,4 and the USA.1,2
The study by Marchetti and Rossiter3 went a step further in trying to estimate the true cost of HAIs in US acute care hospitals by assessing the full social burden of these infections including direct medical, non-medical and indirect costs. This was done by updating, combining and expanding previous cost estimates from various studies. Although the study was subject to the same limitations as the studies which contributing data was derived from, it is of importance because the social cost of HAIs is rarely considered. Marchetti and Rossiter estimated the total social cost of HAIs in US acute care hospitals alone (excluding those occurring in non-hospital settings) to range from $96-147 billion. In the face of such a huge cost, the authors concluded “The enormous clinical and economic burden of infection places HAIs high on the list of devastating and costly illnesses, such as cancer, heart attack, stroke, and diabetes, thereby mandating further research and greater efforts to contain a pressing healthcare problem”.
It is clear that HAIs represent a huge burden in the developed world. Due to the limited data available from low- and middle-income countries, the true cost of these infections is undetermined, although it is clear that prevalence is higher in these countries. More research is needed to evaluate the true burden of HAIs worldwide, including their financial cost, to expose a problem that is as devastating and costly as cancer and diabetes. Needless to say, the implementation of practical and effective strategies to reduce the prevalence of HAIs is required.
*Healthcare-Acquired Infections, also known as “Healthcare-Associated Infections”, “Nosocomial Infections” or “Hospital Infections”, are infection acquired by patients in healthcare facilities or appear after discharge from a healthcare facility and are not present or incubating at the time of admission. Their definition also extends to occupational infections among healthcare workers.
- WHO. Report on the burden of endemic Health Care-Associated Infection Worldwide. WHO. 2011.
- Zimlichman E, Henderson D, Tamir O et al. Health Care-Associated Infections: A Meta-analysis of Costs and Financial Impact on the US Health Care System. JAMA Intern Med 2013.
- Marchetti A, Rossiter R. Economic Burden of Healthcare-Associated Infection in US Acute Care Hospitals – Societal Perspective. J Med Econ 2013.
- Annual epidemiological report on communicable diseases in Europe 2008. Report on the state of communicable diseases in the EU and EEA/EETA countries. Stockholm, ECDC. 2008.
- Klevens RM, Edwards JR, Richards CL Jr et al. Estimating health care-associated infections and death in US hospitals, 2002. Public Health Reports 2007;27:817-824.