Antibiotic prophylaxis isn't needed for removal of below the knee orthopedic implants?

Wow, it has been wicked cold this week and it's only going to get colder. It's so cold that I stayed inside and read JAMA RCTs instead of racing to the mall and fighting for discounted gift wrap. Besides adding to my ID knowledge, perhaps this latest polar vortex is also behind the reduced flammability of the ID profession? One can only hope.

The folks that follow me on twitter know the real reason I'm staying current on JAMA studies is that I've recently accepted a position as an Associate Editor for a new JAMA journal called JAMA Network Open. This open-access journal will begin accepting manuscripts in early 2018. Get those fingers typing - one way to protect yourself from frostbite...

In the Boxing Day issue of JAMA there was a very nice multicenter, double-blind RCT comparing surgical site infection rates post removal of below-the-knee orthopedic implants in patients receiving 1g cefazolin vs saline placebo. The 470 randomized patients were from 19 hospitals in the Netherlands and patients were excluded if they had active infection, fistula or were receiving antibiotics. Outcomes followed CDC definitions. Implant removal is considered a clean procedure with expected SSI rates of 2 to 3.3%, so apparently antibiotic prophylaxis isn't indicated; although reported SSI rates have been higher in removal vs implantation procedures, so some recommend prophylaxis.

Spoiler alert: The study was negative. 13.2% of patients in the cefazolin arm and 14.9% in the placebo arm developed SSI, (absolute risk difference, −1.7 [95% CI, −8.0 to 4.6], P = .60). Results below in Table 2. Thus, with a negative study, I headed to the sample size calculations section where the authors stated that they powered the study with an estimated SSI rate of 3.3% in the cefazolin arm and 10% in the placebo arm based on the SSI rates in clean-contamined procedures and recent Dutch retrospective studies, respectively.

Few thoughts. First, this is an underpowered study. It's true that they hit their target sample size, but their estimates were completed using rosy expectations for the benefits of cefazolin and were not selected based on clinically meaningful reductions in SSI. Many might think a 2% absolute reduction in SSI is clinically meaningful. Second, the authors suggest that the high rates of SSI might have resulted from very low thresholds for starting antibiotics if there was "the slightest suspicion of a SSI." Since CDC definitions define SSI based on receipt of antibiotic treatment, this behavior could have biased the rates. Finally, deep SSI rates were 0.4% (1 patient) in the cefazolin group and a far higher 2.9% (7 patients) in the placebo group, (absolute risk difference, −2.5 [95% CI, −5.7 to 0.4]). Since the study was powered for the primary outcome, all SSI, not much was made of the big difference in deep SSI. 

The end result might be disappointing but this is no discredit to the authors and clinicians behind the study - RCTs are very hard to design and implement  - thumbs up for all their efforts. With that said, I would prescribe cefazolin as a peri-operative antibiotic during implant removal below the knee since a 2% absolute reduction in all SSI and a 2.5% reduction in deep SSI are both clinically meaningful benefits. I will then wait for another larger study powered using clinically meaningful SSI targets, including deep SSI.

The smoldering dumpster

I’m a bit delayed this year in commenting upon the ID Match results—go here for our prior posts on this topic (and the broader issues affecting recruitment into our specialty).

IDSA has a good summary of the results, and the figures below are taken from that article. The overall message is: the dumpster fire is no longer raging, but the dumpster is still smoldering! We’ve basically held steady since the new “all-in” Match started last year, with similar percentages of programs and positions filled. 

How to interpret the numbers? I think the “all-in” rules have reduced some (most?) of the outside-the-match ‘strategery’ that some programs and applicants were practicing. Thus after a couple years of “all-in”, we have a more accurate picture of the supply-demand relationship for ID training. This picture is far from pretty—a third of programs are going unfilled, representing one in five of our training spots. Clearly, “train longer to make less” is still a difficult reality to overcome, even for a specialty as fascinating and fulfilling as ID.

So we have a lot of progress to make, and it will have to be made against some pretty stiff headwinds. Easily lost in the numbers is the substantial proportion of positions filled by international medical graduates. This is a great thing in my view, bringing diverse experience and perspective to our programs—but it also makes demand for ID training highly vulnerable to corrosive political forces that may make it less inviting to come to the U.S. for training and employment. If IMG numbers fall, the dumpster fire will rage anew.

Finally, the political landscape will undoubtedly also shape the U.S. healthcare system in ways that are unpredictable, but which could reverse some of the trends favorable to ID (e.g. focus on population health and value, with requirements that promised to provide more fulfilling job options for ID—stewardship and infection prevention among them). The strong anti-regulatory mood of the current administration, along with increases in the uninsured population, could reduce incentives for healthcare systems to invest heavily in quality and safety. 

To sum up, this year’s match should serve as a continued call-to-action, as we still have huge challenges ahead as a specialty.

-->

Holiday gift idea!

Anyone who practices hospital infection prevention knows how many “data gaps” exist—gaps that make it very difficult to decide which approaches ought to be implemented in your own facility. Should we institute a no-touch disinfection technology? Implement universal decolonization? Use gowns and gloves for all ICU patients? Spend money on an automated hand hygiene monitoring system? Establish a bare-below-the-elbows attire policy? Invest in antimicrobial impregnated textiles (curtains, scrubs, etc.)? Recommend probiotics for selected patient populations?

In the absence of definitive studies, we want carefully considered opinions from smart people who have a wealth of experience in infection prevention. Right?

So if you’re looking for holiday gift ideas for your favorite hospital epidemiologist or infection preventionist, check out this new textbook: “Infection Prevention: New Perspectives and Controversies”, edited by our friends Gonzalo Bearman, Silvia Munoz-Price, Dan Morgan and Rekha Murthy. The text is a nice companion to this blog—in addition to covering all the above questions (and more), the chapters are generally concise, well-written and appropriately referenced. The emphasis is not on being encyclopedic, but on addressing the top-of-mind issues that hospital epidemiologists and infection preventionists deal with most often.

Should surgeons be allowed to prescribe antibiotics without assistance?

It's the end of a long day on the ID consult service. You and the team have decided to recommend switching antibiotics on a post-op cardiac surgery patient since the S. aureus susceptibilities have returned and you'd prefer cefazolin over vancomycin for her MSSA bacteremia. The team text messages the primary surgical team and the intern meets the team in the ICU. You overhear the ID fellow's discussion with the surgical intern, who appears to not know the patient and who can't get approval from the senior resident, CT surgery fellow or the attending to make the antibiotic change since the whole team is scrubbed in the OR.

The above scenario is all too familiar to those who practice infectious diseases, and to be fair it could apply to other procedure-based subspecialties. But the question arrises, if only oncologists can prescribe chemotherapy, why is it that everyone is allowed to prescribe antibiotics? Is this really what is best for our patients? Yes, this is currently a controversial topic but these are the types of questions we need to ask if we're going to respond to the antimicrobial resistance crisis.

A group of researchers in the UK led by Esmita Charani and Alison Holmes began exploring the effects of culture and team dynamics on antimicrobial prescribing during surgical ward rounds and the results of their ethnographic study left me convinced that we must develop ways to improve antimicrobial prescribing on surgical services.

The research team observed the antimicrobial prescribing decision making of six surgical teams over a 3-month period. These included observation of 30 ward rounds and face-to-face, semi-structured interviews of 13 clinicians (5 consultant/attending surgeons, 3 registrars/residents, 2 nurses, 2 junior doctors/interns and the ward pharmacist). The qualitative analysis identified 4 key themes that influence antibiotic prescribing: (1) working in a constant state of flux; (2) communication jigsaw; (3) delegating antibiotic management; and (4) the need for an intervention. Here are a few quotes from the study:

Constant flux: There is a hierarchy as to who leads ward rounds (WR), but this is a shifting hierarchy whereby people are promoted or demoted from their position based on who is present on the WR...if the surgeon leading the WR is called away, for example to the OR, the line of authority shifts downwards and people must act up, for example the registrar takes on the role of the surgeon, the junior doctor ‘becomes’ the registrar and the medical student ‘becomes’ the junior doctor.

Communication jigsaw: WRs are often rushed, interrupted and dispersed and reconvened because of demands for the senior team to be in the OR. The constant disruption and people leaving and joining the WR means that members of staff will rarely be present for the entire WR. Because of being constantly split between the OR and the ward, communication within the surgical team occurs across different platforms. Key decisions are made, recorded and communicated not necessarily in medical health records but on handover sheets, text messaging, and applications on smartphones (e.g. WhatsApp). On many occasions a patient was thought to be on antibiotics by the team, and after further queries in notes and charts was found not to be on them, and vice versa.

Delegating antibiotic management: Surgeons tended to see the core elements of their role as relating to the surgical management of their patients, a role that is performed in the OR. The lack of priority given to antibiotic decision making is compounded by a lack of expertise, resulting in responsibility for antibiotic decisions being commonly delegated to others.

The need for intervention: The need and expectation to intervene means that often antibiotics are initiated for patients with no or little evidence of infection, but a high plausibility of infection in the minds of the surgeons. This process is rationalized by the surgeons as being an extension of their roles as ‘interventionists’. In the absence of evidence of infection what drives antibiotic decision making is a risk of failure, and a risk of blame. What is considered unique in surgery is that a patient has to be well enough to be able to undergo an operation, therefore any deterioration postoperatively is assumed to be a consequence of the surgery, and the decisions of the surgeon, and not the patient's underlying illness. These concerns drive a more conservative approach to antibiotic decision making leading to unnecessary and prolonged courses of antibiotics.

None of these points will appear very surprising to anyone who has cared for patients on a surgical service. However, the authors are to be commended for the care with which they completed this study and the wonderful structure they provided to the domains that influence antimicrobial prescribing. I agree with their assessment that "there is a need to explicitly assign the responsibility for antibiotic management of the surgical patient to a responsible, individual with necessary expertise... Diagnosis and treatment of infections is a specialty that requires expertise and training, therefore this is an opportunity to develop, with support from specialist microbiology laboratory and staff, a role for a clinician(s) responsible for perioperative antibiotic management. This will help to strengthen the antibiotic management for surgical patients and has the potential to facilitate continuity of care and to help overcome the substantial gaps in communication that have been identified in this study...The time is right to question whether we need to address the gap in antibiotic prescribing for surgical patients by developing this specific perioperative clinician role to manage infections. This is of critical importance considering the rising challenge of antibiotic resistance in postoperative patients."

They will never stop...

....trying to kill the Prevention and Public Health fund. We’ve blogged about this before, here, here, here, here, here, and sadly, again today.

The House of Representatives just voted to reauthorize the Children’s Health Insurance Program (CHIP), which is a good thing—but decided to pay for it with cuts to Medicare and with a huge slash to the Prevention and Public Health fund, which is a very bad thing that will harm many effective prevention efforts. Here is a list of what this fund supports, including expansion of laboratory capacity to detect and respond to emerging infections and antimicrobial resistance, and improvement of state public health infrastructure to detect and prevent healthcare-associated infections across all health care settings.

Meanwhile, our Congress is also planning a massive reduction in corporate taxes with no plan to pay for it (besides adding to the deficit).

Priorities!

De-implementation and Noninferiority in Infection Control Studies

De-implementation or "stopping practices that lack supporting evidence" is a popular topic in infection control circles. In fact, just yesterday I read a discussion where the authors suggested we no longer need to practice hand hygiene after removing gloves when caring for patients with CDI. I guess there aren't randomized trials - you can't be serious!

Which brings me to a recent review in the NEJM by Laura Mauri and Ralph D'Agostino titled "Challenges in the Design and Interpretation of Noninferiority Trials."  This review is very well written - perhaps required reading for epidemiology students well written. In infection control, it is important to recognize that most de-implementation studies are really non-inferiority trials. For example, when we discontinue contact precautions, we are really suggesting that "stopping contact precautions" is non-inferior to continuing contact precautions in preventing MDRO transmission - of course ignoring that compliance with contact precautions is probably so poor that they are basically the same intervention!

In the contact precautions example, we would be testing whether stopping contact precautions "is not worse than the control (continuing contact precautions) by an acceptably small amount, with a given degree of confidence." The null hypothesis would be that discontinuing contact precautions leads to higher transmission of MDRO (i.e. is worse) and rejection of the null hypothesis is used to support the claim that discontinuing CP is noninferior. Here I suggest you stare at Figure 1 for a bit (probably easier to read in the paper with the description of each condition, but I have included it below anyway)

Further discussion about the design and analysis of these trials is way beyond the scope of a humble blog post; however, the authors include nice descriptions of methods for deriving noninferiority margins, the "constancy assumption" and statistical analysis approaches. But their 6th and 7th components of noninferiority trials are worth mentioning from an infection control standpoint:

6) Adequate ascertainment of outcomes: The authors write that "incomplete or inaccurate ascertainment of outcomes, as a result of loss to follow-up, treatment crossover or nonadherence, or outcomes that are difficult to measure or subjective, may cause the treatments being compared to falsely appear similar."  I would suggest that studies that seek to de-implement contact precautions that do not include admission/discharge surveillance cultures seeking to detect transmission events fail this criteria.

7) Issues with "Intention-to-Treat" in noninferiority designs: In a superiority studies (typical RCTs), intention-to-treat analysis, where anyone who receives the treatment is included even if they get one dose, is the gold standard. The authors write: "In a noninferiority study, however, if some patients did not receive the full course of the assigned treatment, an intention-to-treat analysis may produce a bias toward a false positive conclusion of noninferiority by narrowing the difference between the treatments. In some instances, a per-protocol analysis, which excludes patients who did not meet the inclusion criteria or did not receive the randomized, per-protocol assignment, may be preferable in a noninferiority trial. However, a per-protocol analysis may include fewer participants and introduce postrandomization bias. In general, both the intention-to-treat and per-protocol data sets are important. We suggest analyzing both sets and examining the results for consistency."

Just some things to think about as we read the coming wave of de-implementation studies in infection control including diagnostic stewardship.

Wrong answer

This morning I stumbled upon this piece, Wrong Answer (free full text here), by Rachel Aviv in The New Yorker. It's an old article from 2014, but a wonderfully written, compelling, sad tale. It's the story of how high stakes standardized testing of middle school students in economically disadvantaged neighborhoods in Atlanta led to cheating by teachers. It focuses on Damany Lewis, a superb teacher totally committed to his students, who tirelessly worked to improve his students' math knowledge and was successful in doing so, but not successful enough to hit an unreachable goal. Responding to increasing pressure to raise testing scores, he and other teachers began to change the answers on students' tests. We all know that cheating is unethical, and at first glance I bet most of us would argue to punish those involved, but read this entire piece (warning: it's long), and you're likely to soften your stance. The consequences of not meeting unreasonable targets were so severe that the teachers felt compelled to cheat in the best interest of their students.

Now take this article from the education setting into the world of healthcare epidemiology, and if you're like me, there will be chills going down your spine as you read it. It should be required reading for anyone who works in healthcare quality or the key stakeholders in this space, from those at the front lines to those who work in professional societies, and to those who create policy at the state or national level. There are also lessons here for patients and patient advocates.

Donald Campbell

What happened in Atlanta shouldn't surprise us. In 1979, Donald Campbell, a psychologist, published a paper, the crux of which has become known as Campbell's law. I wasn't aware of this until I read Aviv's article. It states: "The more any quantitative social indicator is used for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor." Moving this to our world, you can delete the word "social" in Campbell's law and take a look at Dan Sexton's commentary, Casablanca Redux, from 2012. Here's an excerpt:

Our informal discussions with other hospital epidemiologists, our experience in evaluating the source of infection in hundreds of bacteremic intensive care unit (ICU) patients, and common sense have led us to suspect that many hospitals do not accurately report their true rates of CLABSI, using current NHSN definitions. In some cases this may reflect an unwillingness of local staff to accept these definitions as accurate or fair; in other situations it may reflect an unconscious desire to hedge or reduce their rate of CLABSI to avoid criticism and negative consequences from their local supervisors in the press, clinicians, or the general public who review their publicly reported data... If clinicians inappropriately or illogically fear or anticipate negative feedback about the rate of CLABSI in their institutions, they may consciously or subconsciously fail to obtain blood culture results for every patient with a possible or likely BSI. Simply put: no culture equals no infection, using standard definitions of CLABSI. 

At some level, we are all complicit in this. And depending on the action, it may not be the wrong thing to do. In fact, it may benefit the patient. For example, better diagnostic stewardship in the form of appropriately ordering fewer urine cultures not only lowers CAUTI rates but reduces antibiotic utilization with several resultant benefits. Still it's important to note that the primary impetus for this was to lower HAI rates. We take into consideration how a new diagnostic test may impact HAI rates and may even allow that to impact the decision to implement (see an excellent paper by Dan on this here). We may allow clinicians to censor infections that infection preventionists have detected even though the cases meet NHSN definitions. And at the extreme, hospitals may engage in practices that may harm patients in order to reduce publicly reported HAI rates. In a recent publication on how physicians in training view quality initiatives, a dirty secret was elicited from a resident during a focus group at an academic medial center: “There’s like the central line infection protocols…. If you suspect that anybody has any type of bacteremia, you don’t do a blood culture, you just do a urine culture and pull the lines … we just don’t even test for it because the quality improvement then like marks you off.” 

While reading Rachel Aviv's paper, I wondered: Do we ever ignore results (i.e., infection rates) that seem too good to be true like the educational administrators in Atlanta did? Do we critically analyze surprisingly good results to the same degree as we do surprisingly bad results? In Damany Lewis' case did the end justify the means? Is there ever a situation where I could be pushed to a similar point as Lewis?

The Atlanta school system harmed students and teachers in a thoughtless quest to improve quality. There were no winners. Sadly, the response to the cheating scandal was to raise the stakes for test scores even higher. With pay for performance the same is happening in health care.

Chlorhexidine bathing outside the ICU: Await the ABATE!

Daily chlorhexidine (CHG) bathing has become routine in many ICUs. Given that more healthcare-associated infections (HAIs) (including more central-line associated bloodstream infections (CLABSIs)) occur outside of the ICU, many hospitals have also implemented this practice on general medicine and surgical wards. However, to this point there are few data to support the effectiveness of CHG bathing outside of ICUs. 

So I was very excited to hear Susan Huang present the results of the Active Bathing to Eliminate Infection (ABATE) study at IDWeek last week. Similar to the REDUCE MRSA study, this 53 hospital cluster-randomized trial took place in the Hospital Corporation of America (HCA) system. Units were randomized to routine care or decolonization (this consisted of daily CHG [4% rinse-off shower or 2% leave-on bed bath] with addition of mupirocin nasal ointment for 5 days if + for MRSA by history or culture/screen) for a 21-month intervention period (after collecting baseline data for 12 months). The primary outcome was MRSA or VRE clinical isolates, and the main secondary outcome was any bloodstream isolate attributed to the unit (for common commensals, 2 or more + cultures).

With the requisite reminder that it is always best to wait for the peer-reviewed publication to make firm conclusions, the results presented at IDWeek suggest the likely take-home from this study: No measurable benefit in the entire population, but significant reductions in MRSA/VRE clinical cultures and bloodstream infection in the subgroup with devices (central lines, midlines, and lumbar drains). This subgroup represented 12% of the study population but accounted for 34% of all MRSA/VRE events and 59% of bloodstream infections. The additional reductions in the decolonization arm for this subgroup (compared with routine care) were 32% for MRSA/VRE cultures and 28% for BSI (both highly statistically significant). 

Once published, these findings will leave infection prevention programs with some interesting decisions. A quick take might be, “OK, let’s just use CHG in those non-ICU patients with devices (or just central lines).” However, this isn’t what the ABATE trial evaluated—it showed a substantial reduction in MRSA/VRE/BSI outcomes in patients with devices when everyone else was also receiving CHG (+/- mupirocin). To assume that the decolonization of the non-device population had no beneficial effect on those with devices is to discount any potential role for reduction in pathogen transmission between non-device and device patients. Another tricky question has to do with the role of mupirocin—adding this agent to CHG for known MRSA carriers without knowing how important this component of the intervention was adds some logistical complexity, cost, and antimicrobial resistance concerns (the investigators are also doing the microbiology work to assess for CHG and mupirocin resistance emergence). 

We’ll revisit this study once it is published and all the details are available. For now we should congratulate Susan and the entire ABATE trial team for another tremendous contribution!

IDWeek 2017 is in the books

I'm back from IDWeek 2017 in San Diego -- always good to reconnect with old friends, meet new colleagues, and hear the latest in infection prevention and antibiotic stewardship science and practice.  This year I noted an increase in pro-con and clinical controversies sessions, which I think are so valuable for those of us struggling day-to-day with issues where the evidence base is absent or opinion is conflicting.   If you didn't get a chance to attend, fear not, as I am sure there will be more conference-related news emerging over the coming weeks (all 6 of your favorite bloggers made an appearance). 

Of course, it's never too early to think about next year -- IDWeek 2018 heads back to the left coast, this time it's San Francisco, October 3-7, 2018 (mark your calendars!).  I'm among the SHEA contingent for the planning committee (along with Hilary), and we're very interested in program suggestions -- please send them our way.

I'll leave you with one meeting tidbit -- Shelley Magill presented the results from the CDC's 2015 HAI Prevalence study, a follow up to their 2011 survey that was published in the NEJM.  In the 4 years since the first survey (using the same hospitals included previously):

• The HAI prevalence rate among hospitalized acute care patients fell from 4.1% to 3.2% (a 22% decrease)
• Central line and urinary catheter use were both significantly lower
• Healthcare-associated UTIs and SSIs significantly decreased

Nice to see some positive news to reflect the extensive HAI prevention efforts nationwide.  Of note, antimicrobial use stayed stable, reinforcing the need for increased antibiotic stewardship efforts.  Given the enhanced focus in this area, I am hopeful that the next prevalence survey will show improvement on that end as well.

Unwarping the playing field

Easing comfortably into my role as a "blogger," I've realized how easy it is to adopt a few key platform issues that tend to drive one a bit mad.  This blog isn't so fond of CAUTI, contact precautions, or devices that blow moist, warm particles over sterile fields (but then again, who is?).  We love diagnostic stewardship, influenza vaccination (um, mostly), and fecal transplantation.

Add advocating for better risk-adjustment of publically-reported HAI performance to my list.  A few months ago, I blogged about this issue and poor reporting validation by CMS -- now some excellent papers on improving risk adjustment have emerged, both from many FOB (friends of the blog) with senior authorship by Anthony Harris and his group at Maryland.  One focuses on SSI and one on CLABSI.  Their methodology is very similar and has some key features:

• They used comorbid conditions that are components of the Charlson and Elixhauser comorbidity indices
• These conditions were captured by diagnostic discharge coding that are currently routinely collected and submitted to CMS, limiting the data collection burden 
• They used conditions identified using Delphi consensus methodology from a survey of ID and infection prevention experts, providing some clinical credibility to the process

The authors examined the model performance and assessed changes in hospital rankings when compared to the traditional NHSN models. For SSI, a model containing procedure type, patient age, race, smoking history, diabetes, liver disease, obesity, renal failure and malnutrition showed good discrimination, and 86% of hospitals changed ranks within the cohort when the risk-adjusted model was used -- with 4 hospitals changing by >10 ranking spots.  For CLABSIs within the ICU, a model using coagulopathy, paralysis, renal failure, malnutrition and age showed improved predictability when compared to the NHSN ICU model, and 45% of hospitals changed ranking.  The authors note the clear limitations, including some of the challenges with using coded data, but these papers are important advances in the area of publically-reported HAI data.

You can read some of my more detailed thoughts in the accompanying editorial for the CLABSI paper (shameless plug).  At a time when there are many consequences for a hospital's performance on these surveillance metrics (e.g. last year my hospital received a draft quality incentive contract from a private insurer that required our large, tertiary care center to have ZERO of the Big 6 reported HAIs, to the tune of several million dollars in incentives), leveling the playing field to adjust for those factors that lead to HAIs that are beyond the control of the hospital is essential.  Thankfully, the CDC and HICPAC have recently chartered a new NHSN work group (disclaimer: Hilary and I serve on this group) and the issue of improved risk adjustment seems to be a major emphasis - fingers crossed that the field will start to level soon.

When prevention success stagnates? Treat the patient!

Prevention is paramount – I do believe this, and I know that is so much of what healthcare epidemiologist strive for; however we often become very myopic and focus exclusively on “modifiable risk factors.” It is refreshing to read a nicely done epidemiologic study to illustrate what an impact the infectious disease community can have by improving the way we approach patient treatment. When reading the recent article in JAMA IM by Michihiko Goto and colleagues I was expecting a nice ecologic study showing an impressionistic picture of how improved treatment processes correlate with improved MRSA bacteremia mortality - but our VA colleagues working with big data have painted more of a realistic 

Le Déjeuner sur l’herbe Painting 

by Édouard Manet, 

1863 Musée d’Orsay, Paris

Google Arts & Culture

than an impressionistic picture. Using the VA database, capturing deaths occurring during both the inpatient stay and the post-discharge period, they quantify improved survival at the patient level is driven by improved processes of care for S. aureus bloodstream infection (Association of Evidence-Based Care Processes With Mortality in Staphylococcus aureus Bacteremia at Veterans Health Administration Hospitals, 2003-2014 JAMA IM).

I have been pushing for transitioning efforts to prevent S. aureus (more specifically MRSA) bacteremia to the post-discharge setting, worried that the recent reductions observed among hospital-onset MRSA BSI are not being realized in the post-acute care setting. We’re getting stuck; in fact we have been stuck for a while at preventing community-associated MRSA BSI (See figure). 

Goto and colleagues provide some clarity to preventing deaths related to MRSA BSI (and S. aureus BSI overall) even during periods of prevention stagnation such as we may be in currently. Of note, the incidences of healthcare-associated and hospital-onset MRSA BSI decreased in VHA hospitals between 2003 and 2014, whereas the incidence of CA bacteremia was stable. This is identical to trends illustrated nationally using CDC's EIP data, suggesting the VA analysis may be reflective of what is going on nationally.

Goto utilized the national Veterans Health Administration (VHA) health care system to first determine how to best risk adjust mortality; and then determine the independent effect of each of three pillars of guideline directed processes of care for managing S. aureus bacteremia (SAB): (1) appropriate antibiotic therapy, (2) echocardiography, and (3) consultation with ID specialists. They report lower risk-adjusted mortality among patients with SAB when they received (1), (2), or (3), and there was a nice dose-response relationship between the number of care processes and mortality. They estimate “57.3% of the decrease in risk-adjusted mortality among patients with SAB between 2003 and 2014 could be attributed to increased use of these evidence-based care processes.”

Their paper also sheds some light on the importance of capturing post-discharge data when quantifying mortality related to processes or infections related to the hospital setting!. Risk-adjusted mortality decreased from 23.5% in 2003 to 18.2% in 2014, regardless of MRSA, MSSA, and place of acquisition (Figure).

From Supplemental Figures, Goto et. al.

I was caught by the discrepancy between these mortality rates and the mortality reported by the CDCs Emerging Infections Program invasive MRSA Surveillance, reported around 12%. The latter is limited to in-hospital or 30 day mortality, whichever comes first. Recent data at IDWeek by one Emerging Infection Program site identified another 30% of deaths among patients with MRSA BSI occurred post-discharge. The Goto paper captures these deaths, making their conclusions more realistic. In addition, their risk adjustment for mortality included over 13 comorbidities, timing of infection, and susceptibility. They did an outstanding job of trying to evaluate the relative importance of each care process while accounting for changes/absence/presence of these underlying predictors of mortality (both inpatient and post-discharge). They even did a sensitivity analysis to account for early deaths, before these care processes could occur. Furthermore, the impact of receiving the care processes was similar regardless if the SAB was hospital-onset or community-onset!

The bottom line – following evidence base care processes does save lives. Their analysis support their conclusion that “there is a need for continued implementation of quality improvement initiatives to increase the adoption of these evidence-based care processes for patients with SAB.” Let’s be bold and call these what they are: performance measures! Here we have a potential metric (proportion of SAB receiving said care process), that are closely linked to improved survival, and can be captured electronically in an objective manner (at least in the VA!) improving the reliability of these metrics across facilities. I was glad to find through a google search that IDSA recently (December 2016) urged CMS to move in this direction -- although the details of the status of this proposed measure (#407) are not clear to me.

While we anticipate novel therapeutics for MRSA BSI including immunotherapy adjuvants or vaccines to become available in the not to distant future; quality improvement efforts in the evidence-based processes of care for SAB now will likely improve our patient’s outcome. I hope we can turn our attention here soon -- and have hospitals rewarded for doing so.

ICD Coding and MDRO - If you don't bill for it, it doesn't exist

Fact 1: Infectious Disease specialists are among lowest paid physicians in the US

Fact 2: Many infectious diseases, including HAI, are absent from ICD billing codes or are poorly coded, and thus the true population health impact of infections, particularly MDROs, is invisible

Hypothesis: If we could improve ICD codes for infectious diseases, ID salaries would increase and the field could be saved from extinction

Many of us on the blog have lamented about the current state of ID with a particular focus on low relative salaries compared to other medical subspecialties and concerns about the annual fellowship match. If we focus on academic ID, the folks who supposedly will train the next generation, we also need to worry about low levels of NIH funding for anything other than HIV research; a trend that is slowly improving. (Fact 1, above)

Our group has looked at the accuracy of ICD billing codes for both HAI and MRSA and the results are not pretty. Michi Goto completed a systematic review of ICD code accuracy for CDI, SSI, VAP/VAE, CLABSI, CAUTI, post-procedure pneumonia and MRSA. He found that apart from CDI and orthopedic SSI, the codes have poor sensitivity and specificity. Marin Schweizer looked at the validity of the V09 code pre-2008 for MRSA and found it to be a very poor at detecting proven incident MRSA infection. (Fact 2, above)

Since many of those studies were completed, there have been new codes added for CLABSI (October 2011), VAE/VAP (October 2008), MRSA infections (October 2008), and post-procedure pneumonia (October 2012). So there is some hope that HAI and MRSA will become better recognized. But what about MDROs?  Investigators from Wash U (including co-blogger Hilary) just published a research letter in ICHE that calculated the sensitivity of ICD-9 codes for various MDRO at their hospital between 2006 and 2015. The gold-standard was a culture at a sterile site or BAL/brochial wash culture with an MDR-Enterobacteriaceae, Enterococcus spp., Staphylococcus aureus, Pseudomonas aeruginosa, or Acinetobacter spp.

As you can see in their Table 1, apart from MRSA (after 2008 code added) and P. aeruginosa, ICD organism coding had poor sensitivity and MDRO/V09 codes were - terrible. The authors concluded: "ICD-9-CM diagnosis codes cannot be used to estimate the burden of MDRO infections in hospitals."  I think we'd all agree. I would have liked to see more information on the specificity and positive/negative predictive values of individual codes (I understand this was a Research Letter).  I'm not sure what the ultimate solution is, but perhaps SHEA or IDSA (or ASM) could work to update ICD-10 codes and come up with ways to encourage accurate coding for infectious diseases. If we don't make sure infections "exist" in administrative data, the field of infectious diseases might not exist for long.

image source

When the US opioid epidemic causes a Serratia outbreak

We are in the midst of an almost unprecedented opioid epidemic in the U.S.  Last year (2016), overdoses caused 64,000 deaths, which was a 22% increase from the previous year, while fentanyl-associated deaths increased by 540% over the past three years. (I wanted to add a thousand exclamation points after the 540, but thought better of it)

Fifteen years ago, Belinda Ostrowsky reported a 26-patient outbreak of S. marcescens bacteremia in a surgical ICU that was ultimately linked to contamination of fentanyl by a respiratory therapist who had diverted the narcotic for their own use. (The CDC has a nice webpage describing 30-years of HAIs associated with drug diversion by healthcare workers)

Given the current opioid epidemic, we should expect an increase in hospital outbreaks associated with narcotic diversion. So, it is not surprising to read about a five-patient cluster of S. marcescens bacteremia linked to narcotic diversion by a PACU nurse just described in ICHE by Nasia Safdar and colleagues at University of Wisconsin. Even before the Serratia cluster was identified, a nurse found hydromorphone and morphine PCA syringes with the tamper-evident caps no longer intact and drug levels undetectable in a locked automated medication dispensing cabinet. The subsequent investigation eventually found 42 syringes had been tampered with and narcotics replaced with saline or lactate ringers before the nurse was fired. Unfortunately, even though the outbreak was clonal, the tampered syringes were destroyed before they could be cultured. However, four patients were epi-linked to the PACU nurse and the fifth patient was the nurse's father. (I resisted adding an exclamation point here too)

There you have it, but if you want to read beyond the ICHE report, there is an interview of Dr. Safdar over at STAT. We certainly don't need more things to worry about with the current opioid epidemic, but we should all make sure we keep talking with our pharmacy colleagues about narcotic thefts and keeping our theft policies and prevention practices up to date.

Donation

What a terrible couple of weeks. Hurricanes Harvey and Irma, not to mention a huge earthquake in Mexico, pummeled North America. If possible, one of the things that we can do in these situations is donate to recovery efforts. Here are a couple suggestions for places where you can donate:

UNICEF has sent teams to Chiapas and Oaxaca and has expanded their fundraising efforts to cover those affected by the hurricanes and earthquakes. Donate please

The five living past Presidents have started the One America Appeal, which initially responded to Harvey but has been expanded to assist with Florida's recovery. Donate please

Finally - and we have been hesitant to even mention this -  many SHEA members have completed races to raise funds for antimicrobial stewardship scholarships through the SHEA Education & Research Foundation's "Race Against Resistance." Runners have included fellow bloggers Tom and Scott. Not to be outdone, the University of Iowa has put together a team 5k run on September 30th.  We hope you can contribute to this important educational and prevention effort. Donate please

Thank you

Are "One-Offs" Becoming Routine

one–off

play

adjective \ˌwən-ˈȯf\

After eight years investigating hospital outbreaks, and about 15 years trying to make the best possible use of surveillance data while at CDC, I still struggle with the tensions inherent in mixing surveillance and performance measurement. The past decade has been a roller-coaster of thrills and perhaps some spills in terms of attention, resources, refinement, and usefulness of HAI surveillance led by CDC; yes, you could probably blame me for several aspects of NHSN reporting you may find unsatisfying (take your pick – perhaps I will expand another day). However, I having recently retired from CDC and am transitioning to Emory Healthcare and Emory University. Although It has been almost eight months. It has been a fascinating transition. The learning curve is steep, and not just for re-entering clinical medicine (that is another story), but also navigating the pathway which integrates the business of healthcare delivery, quality of healthcare delivery, and research opportunities. Slightly easier was learning how to navigate the Emory Parking situation (took 3 months). Much easier was recognizing that the performance quality metrics linked to HAI prevention are getting a lot of attention and a lot of action. It only took a few sessions listening to the quality improvement teams reporting on their target HAIs to understand two things. First, the C suite leaders really care. I had assumed this while at CDC, but it was illuminating to see up close how hard these teams worked to influence HAI prevention. Second, it was becoming somewhat routine to report out on “exceptions to the rules” of HAI reporting. There are many names for those scenarios when an HAI is justifiably reported, but either considered not preventable with evidence based prevention practices or not clinically the infectious event represented by the HAI. While at CDC we routinely heard about these: CLABSIs that “shouldn’t really be counted”, MRSA BSIs that really “weren’t ours”, CAUTIs that really don’t represent an infection. Now these reported HAIs were being called “one-offs.”

The NYT reports the term ”one-off” comes from earlier industrial beginnings with the quantity of items produced in manufacturing process, such as taking one-off, two-off, or twelve-off the line to sample or give-away. However nowadays it can refer to any exception of the rule – such as a recent one-off boxing match that really should not ever have happened. 

In an HAI paradigm where we aim for 0 infections, one-offs may either be unavoidable (not preventable) or wrongly attributed to the device, location, procedure. I have historically known of these in terms of byproduct of using proxy measures. I had previously published an editorial on the value of proxy measures of infection as a tool for quality improvement (Meaningful measure of performance: A foundation built on valid, reproducible findings from surveillance of health care-associated infections).

In that editorial, we outlined necessary steps to reduce the inaccuracies inherent in using such an approach. Now that progress has been made in HAI prevention since 2010/2012, many of these HAI events that conspicuously remain and continue to plague our patients, often don’t fit neatly into the intent of the surveillance definitions. Left with these “one-offs,” it is often difficult to know what to do more to prevent them. Surgical patients with fistulas and central lines that don’t have an infection related to insertion or maintenance processes, neutropenic patients that don’t quite meet the definition of MBI-BSI, I have even heard of tissue transplantation related bacteremia categorized as CLABSI. No doubt, changes have occurred since 2011 to improve CAUTI reporting, and neutropenia-related bacteremia. However, the pace is slow. The one-offs are starting to pile up. Perhaps improved risk adjustment of HAI data will mitigate the influence of the one-offs on healthcare facility performance measures. Until then, kudos to the quality folks and infection control teams making prevention progress. However, I hope we can reward them soon with improved performance measures. Perhaps there are surveillance lessons that can be learned from these one-offs after all. 

If you are interested in sharing one-off stories I have started a registry here - maybe we can fill in some gaps and accelerate the process of changes in surveillance methods.

And what about antimicrobial scrubs?

Ascot: a neckband with wide pointed wings, traditionally made of pale grey patterned silk

The role that environmental transmission plays in the spread of important pathogens is increasingly recognized. One of the major mechanisms by which pathogens are thought to spread is via contaminated healthcare worker clothing. A major reason that gowns are included in contact precaution is that they are felt to interrupt the transmission from patient/environment to HCW attire. An old (2010) study that Dan Morgan completed found that gowns became contaminated 11% of the time when caring for patients with MDR-Acinetobacter and 5% of the time when caring for patients with MDR-Pseudomonas. A repeat (2012) study found that gowns became contaminated during 4% of HCW visits caring of MRSA+ patients, 5% for VRE, 2% for MDR-Pseudomonas and 13% for MDR-Aceintobacter.

With so much contamination and a desire to rid the world of unnecessary gown use, investigators have been exploring the benefits of antimicrobial textiles, such as scrubs. If these novel scrubs could reduce contamination, maybe we could drop the dreaded gown and go with universal gloves for contact precautions?

Which brings us to a ASCOT study by Deverick Anderson and colleagues funded by the CDC Prevention Epicenters Program. ASCOT: Antimicrobial Scrub Contamination and Transmission. The investigators examined the benefits of two different antimicrobial scrubs (Scrub 1: silver-alloy and Scrub 2: organosilane-based quaternary ammonium and a hydrophobic fluoroacrylate copolymer emulsion) vs standard poly-cotton surgical scrubs in a 3-arm RCT during 3-consecutive 12-hour ICU nursing shifts. The primary outcome was change in total contamination on the nurses scrubs as sum of CFUs. Of note, all MDRO colonized patients in the study were placed on contact precautions and HCW placed gowns over their scrubs and wore gloves while caring for those patients.

The study collected many cultures: 2919 from the environment and 2185 from the HCW clothing. 41 nurses were randomized but one was excluded for a total of 40 nurses caring for 102 patients during 167 encounters. Their primary finding was the scrub type had no effect on HCW clothing contamination (p=0.70) There is a lot to unpack in this study and it warrants a careful read - a lot of data! but I've included Table 3 below with the contamination before/after each shift. Overall, the median CFU increase was 61.5 (interquartile range [IQR], −3.0 to 191.0) in the control arm, 73.0 (IQR, −107.0 to 194.0) in the Scrub 1 arm, and 54.5 (IQR, −60.0 to 215.0) in the Scrub 2 arm.

There were acquisition events during 39 (33%) of the shifts with 20 (17%) environmental acquisitions and 19 (16%) acquisitions on HCW attire. Looking at the 19 HCW attire acquisition events, 12 (63%) were confirmed: 7 from the patient, 3 from environmental contamination, and 2 from the patient/environment.

Overall, the authors reported that there were no benefits from either antimicrobial scrub. However, there was significant transmission from patient or environment to HCW attire.  Back to the drawing board on antimicrobial scrubs?  Maybe. I would like to see the study repeated in a hospital where contact precautions are not used to see if benefits might exist in settings where gowns are not worn when caring for MDRO+ patients. With this much acquisition of nurses' clothing, it's going to be hard to ditch gowns, unfortunately.

Oh, and I love the ASCOT name. Brilliant.

The cartoon editorial, microbiology edition: An idea whose time has come!

I was excited to read the editorial in this month’s Journal of Clinical Microbiology (JCM), by Alex McAdam (JCM Editor in Chief), entitled “Prevalence and Predictive Values”. You can read it here too, because I’ve pasted it below:

Brilliant—a simple concept (diagnostics 101!) explained in a simple format. And as an associate editor of JCM, I can attest that this concept is frequently missed by submitting authors, not to mention practicing clinicians and hospital epidemiologists. 

This issue is also foundational to diagnostic stewardship, as it emphasizes the importance of limiting diagnostic testing to patients who have a reasonable pre-test likelihood of disease (pre-test likelihood being the individual-patient equivalent of population prevalence). 

It also explains why we’ll never “get to zero” for healthcare-associated infections (HAIs), even if all HAIs were preventable. Take the example of hospital-onset C. difficile infection (HO-CDI). The more successful your prevention program is at reducing whatever the “true” incidence of HO-CDI is, the lower will be the population prevalence—and the lower the positive predictive value (PPV) for the very sensitive CDI tests we now use. Positive tests will still occur, no doubt, and will be counted toward the HO-CDI rate—but they’ll be increasingly likely to be clinical false positives. 

Now I need to go start working on a good cartoon editorial about whether CAUTI exists….

Summer Quick Hits (with the Award for the Most Eyebrow-Raising Article Title of the Year)

Trying to recover from summer vacation (Alaska = thumbs up, especially during a summer heat wave) and gear up for a new school (and blogging) year, so here are a few quick hits from recent articles:

Two articles highlight several HAIs that aren't often included in surveillance and prevention efforts:

• Len Mermel has a nice systematic review in CID examining the burden of bloodstream infection related to short-term peripheral venous catheters (a.k.a. peripheral IVs - not midline or PICCs).  Used in a substantial number of hospitalized patients (esp. as we're better about central line necessity), these devices have a much lower risk of BSI when compared to central venous catheters (2-64 fold higher risk for CVCs); however, given the vast number of devices used (Len estimates ~200 million adult patients in the U.S. annually), the number of BSI events are likely high. A number of interesting details are in the paper, so worth checking out. 
• A nice commentary out of the UK in Lancet Respiratory Medicine advocates for an increased focus on healthcare-associated pneumonia, particularly that which occurs outside of the ICU (and is not ventilator-associated). 

Both of these papers highlight HAIs that are not in the "Big 5" (CLABSI, CAUTI, SSI, MDROs/C. diff, and VAE) but cause patient harm.  Broadening an IP surveillance and prevention program to include these events does have some challenges, however.  The worry about objective surveillance definitions that came to a head with VAP certainly applies to HAP, and the volume of patients at risk for a PIV-related BSI invites the need for an automated system for surveillance.  Nonetheless, with reductions in the Big 5 (well, except VAE as I'm still not sure how to tackle that one), it's perhaps time we look to expand our scope.

Finally, a paper that wins the award for the most eyebrow-raising title of the year: "Hematophagous Ectoparasites of Cliff Swallows Invade a Hospital and Feed on Humans."  Try reading that without saying "What?? Gross."  The authors outline their nosocomial "outbreak" of two ectoparasites related to a massive swallow roost on the outside of a community hospital.  One inpatient noted a rash illness, and testing of ticks and bugs identified the presence of human blood in 17% of the captured critters.  Hospital invasion!  Feeding on humans! Talk about a riveting agenda for your next infection prevention committee meeting!

Diagnostic Stewardship

The following is a guest post from Dr. Dan Morgan, GFOTB (Good Friend Of The Blog):

This week Preeti Malani, Dan Diekema and I wrote a viewpoint in JAMA discussing diagnostic stewardship, or “modifying the process of ordering, performing, and reporting diagnostic tests to improve the treatment of infections and other conditions.” In other words, guiding laboratory ordering to prevent contradictory results and reporting results in a fashion that makes treatment more appropriate. There really are two Criteria for Diagnostic Stewardship modifying laboratory testing:

1) Does it modify the process of ordering, performing and reporting tests? 

2) Does it improve the appropriateness of patient management? 

When I discussed diagnostic stewardship with my non-medical wife, she asked “you mean they don’t do that? Why would they do tests that contradict other results or provide second or third line antibiotic choices?” 

This is why I think diagnostic stewardship has so much potential. It is about making laboratory ordering more rational, which is hard to debate. Although medicine has existed with the idea that doctors knew best how to order and interpret results, we are now seeing they often don’t, as predicted by psychologists Danny Kahneman and Amos Tversky in the 1970s; “Intuitive judgments are liable to similar fallacies in more intricate and less transparent problems.” 

Doctors ordering and interpreting test results are like other people, often irrational. Diagnostic stewardship makes testing more logical to improve patient care. Ultimately this process shouldn’t be limited to urine cultures, blood cultures and C. difficile testing but applied to new molecular detection panels and non-ID tests, like cascading tests for anemia or limiting PSA testing in young and elderly men. And there has been interest in this idea from areas outside of ID. 

The fact that diagnostic stewardship reduces false-positive tests that contribute to publicly reported HAIs means there is likely a lot of incentive to support these processes. But we shouldn’t forget there are important patient benefits too, including avoiding unnecessary antibiotics, avoiding the distraction of misdiagnosis, and improving the ability of HAI rates to truly measure care.