Guest Post: Thinking about Contact Precautions

Anthony Harris, MD MPH

This is a guest post from Dr. Anthony Harris, Professor of Epidemiology and Public Health, University of Maryland School of Medicine.

I have a lot of admiration for this blog and in the spirit of academics, I would like to share my somewhat different interpretation of the contact precautions literature. I offer three points for your consideration:
 
1. Contact precautions do not lead to an increase in adverse events: 

Instead of the frequently cited small observational studies, I think it is most important to focus on the one randomized trial that evaluated adverse events associated with contact precautions (I acknowledge my bias in that it is the study I led). A randomized trial should most often trump observational studies especially since it's near impossible to control for confounding by indication, i.e. why was the patient placed on contact precautions. In fact, the latest analysis of our randomized trial data showed a trend towards decreased adverse events in the universal contact precaution arm. (See: Croft L et al. Clin Infect Dis. 2015 Aug 15;61(4):545-53). To quote from the Conclusion: "Concerns of adverse events resulting from universal glove and gown use were not supported." So we should be clear that other than the cost issues of gloves and gowns no high level study has shown any adverse events from contact precautions. Healthcare workers do go into the patient room less often when the patient is on contact precautions but this has not been shown to lead to an increase in adverse events. In my experience (and the data supports this), healthcare workers just bundle their activities and thus perform the same activities in the room with fewer visits.

2. Methodological problems in studies that have removed contact precautions: 

Studies that show no effect of removing contact precautions have serious methodological problems. The largest problem is that they are incredibly under-powered. The studies that show “no difference when you remove contact precautions” are too small to detect a difference and thus may falsely conclude that removing contact precautions is safe.

3. Need a better solution before removing the current standard of contact precautions: 

As much as I would love to stop wearing gloves and gowns, antibiotic-resistant bacteria are a continuing problem. They are not going away and other than MRSA, they are not decreasing. Until we have better solutions, I believe that we should not be abandoning contact precautions. This is particularly true in high risk settings such as the ICU. In the ICU where acquisition of an MDRO leads to infection 20-30% of the time during the index ICU admission, the stakes are too high not to prevent patient-to-patient transmission. I believe that the phase 0, phase 1 and phase 2 data on contact precautions are strong and the biologic plausibility that they prevent patient-to-patient transmission so strong that I don’t think we should abandon contact precautions based on underpowered "removal studies" and an adverse-event literature with few studies with strong internal validity. Of course there are certain settings and certain bacteria where removing contact precautions might make sense and these scenarios should be studied using large, sufficiently powered and methodologically sound trials.

Same data, different conclusion

There's an interesting study in the March issue of Infection Control and Hospital Epidemiology led by Keith Kaye, which examines the hypothesis that the burden of patients in contact precautions has an impact on compliance with contact precautions. The study used surreptitious observers to record compliance with the components of contact precautions in eleven teaching hospitals. Approximately 1,000 observations were performed in the ICU and ward settings. The authors conclude: "As the proportion of patients in contact isolation increases, compliance with contact isolation precautions decreases." 

However, looking at the same data, I came to a different conclusion. I converted the bar graph (figure 2 in the paper) to a line graph which makes it easier to follow compliance with each component of contact precautions as the proportion of patients in contact precautions increases:

Now you can clearly see that the only problem with compliance as the burden of contact precautions increased was with hand hygiene prior to donning of gowns and gloves. Thus, decreased compliance with the contact precautions "bundle" was driven solely by the decrease in hand hygiene prior to patient contact. It has been shown in other studies that hand hygiene is lower prior to contact precautions. And I think there is a very simple reason that this occurs: you can't get the gloves on until your hands are completely dry. Hand hygiene before and after patient contact is an essential component of standard precautions. What sets contact precautions apart from standard precautions is the use of gowns and gloves, and the data in this study show no decrease in gown or glove use as the proportion of patients in contact precautions increases. In addition, the overall usage of gowns and gloves was surprisingly high.

So my conclusion would be that there is a negative correlation between the burden of contact precautions and hand hygiene prior to patient care. And maybe that's not so bad...

Photo: Liberty Voice

Trigger happy?

The University of Maryland group has just published two new papers on the safety of contact precautions. One is an analysis of the data from the BUGG study (published in CID), which was a multicenter study of ICU patients, and the other is a matched prospective cohort analysis at an academic medical center (published in ICHE).

Here’s a quick summary of the two papers:

The authors’ conclusions for both papers are essentially the same: concerns about the safety of contact precautions should not limit the implementation of contact precautions. One paper showed no difference in adverse events and the other paper showed that contact precautions was actually safer than not being in contact precautions, which I think is a counterintuitive finding for many of us. 

The problem that I have with both of these papers is the use of the IHI Global Trigger Tool (GTT) to determine the rates of adverse events. I have three concerns:

1. Are all of the events identified by the GTT causally linked to the exposure? For example, in the ICHE study, the strongest association was found for surgical events, and the association was highly counterintuitive: postoperative hemorrhage was found in 1/148 patients in contact precautions vs 12/148 patients not in contact precautions. Given what we know about contact precautions, particularly that it reduces healthcare worker visits, what could be the causal mechanism for a higher rate of post-operative hemorrhage in patients not in contact precautions? Is there a confounder at play here? There may very well be a causal mechanism but I’m hard pressed to think of one.
2. The IHI GTT only looks for errors of commission, not errors of omission, and it seems likely that errors of omission would occur more commonly when a barrier to care is implemented (contact precautions).
3. The IHI GTT sets a 20-minute time limit for the detection of errors when reviewing a patient chart whether the patient was hospitalized for 1 day or 100 days. In the ICHE study, the patients were matched on length of stay; however, I don’t think this resolves the problem. The GTT’s ability to detect error is time dependent. So when comparing two groups, if one group truly has a significantly higher rate of adverse events, a lower proportion of the events will be detected in the group that has more events, reducing the difference between the two groups. In effect we have surveillance bias.
   
   Even the IHI openly admits that this is an issue. Here’s a direct quote from the GTT manual:

The IHI Global Trigger Tool was never intended to identify all adverse events. Experienced reviewers familiar with the IHI Global Trigger Tool will identify almost all events greater than category E in a patient record that can be reviewed completely within the 20-minute time limit. Events in the E category of harm involve more judgment and at times are not as obvious, so these are less easily identified and may be missed. When the 20-minute time limit is enforced not all adverse events are expected to be identified.

In both of the papers, the 3 issues cited above are likely biasing towards the null, making contact precautions to appear to be safer than it is. So I continue to be concerned that contact precautions may result in less safe care. I think that most people in the hospital epidemiology community regard the University of Maryland researchers as some of the best methodologists in the field, and I certainly hold them in very high regard. Nonetheless, I’m curious about their love for the Global Trigger Tool, and hope that they share their views with us on this blog.

Rethinking contact precautions

I'm working on a talk entitled "Rethinking Contact Precautions" for the Winter Course in Infectious Diseases. If you've never been to the Winter Course, it's a great conference in a casual setting with state-of-the-art lectures on a wide variety of ID topics. And there's lots of skiing. This year, we'll be at Big Sky, Montana, February 14-18.

This weekend, I ran across a brand new paper in Infection Control and Hospital Epidemiology on discontinuing contact precautions. This one comes from Roswell Park Cancer Center where active surveillance (weekly perianal cultures) for VRE was discontinued in March 2011. At the same time contact precautions for VRE infection and colonization were also discontinued. The investigators compared VRE bacteremia rates for the 3-year period before and the 3-year period after discontinuing active surveillance and contact precautions. The 6-year period of the study included over 1,300 patients with hematologic malignancies, bone marrow transplant and lymphoma. Over the study period there were no changes in antibiotic utilization, nurse-to-patient ratio, age, gender, underlying malignancies or length of stay. Importantly, via interrupted time series analysis, there was no significant change in the rate of VRE bacteremia (2.32 infections/1,000 patient days before vs. 1.87 after). This is the third published study (see the others here and here) and there are two more studies in abstract form all showing no change in infection rates after contact precautions were discontinued.

I also re-read Kathy Kirkland's thoughtful paper, Taking Off the Gloves: Toward a Less Dogmatic Approach to the Use of Contact Isolation (free full text here). Kathy was way ahead of the curve with her thinking on this topic. Below is a table from her paper that summarizes the likelihood of benefit for contact precautions:

As I thought more about where we are in infection prevention in 2016, it seems to me that contact precautions is a decrepit concept. When introduced 50 years ago, contact precautions made sense. At that time hand hygiene rates were abysmal, alcohol-based handrubs were not available, patients weren't bathed with chlorhexidine, there were few single-bed hospital rooms, and there was no enhanced technology for environmental disinfection.

Putting it all together, there's little evidence that contact precautions are effective in the non-outbreak setting, and we're learning that nothing bad happens when contact precautions are stopped. At the University of Iowa, we're focusing on hand hygiene, stethoscope wipe down and bare below the elbows. And the list of hospitals forgoing the plague doctor suit for MRSA and VRE grows ever longer.

Putting contact precautions in their place

Last September, I had the honor to attend the Infection Prevention Society's Infection Prevention 2016 conference in Harrogate, England. During the conference, I was fortunate to meet Professor Graham Ayliffe and give the annual Ayliffe Lecture on the Science Behind Hand Hygiene and I also got to meet and discuss infection control with many of the dedicated members of the Society. Attending the IPS conference was a great way to learn how infection control interventions are implemented in other countries.

In particular, I greatly enjoyed meeting and debating! Dr. Fidelma Fitzpatrick of The Royal College of Surgeons in Ireland and Beaumont Hospital in Dublin. I was charged with debating For contact precautions and Fidelma was charged with Against. At the end of the debate, we realized that there was much common ground in our understanding of where and when to implement contact precautions for MDRO prevention. In particular, we realized that the underlying context in which contact precautions are implemented, de-implemented or studied is critical. And by context, we mean things like availability of single rooms or the baseline (poor) hand hygiene compliance in your hospital. With that in mind, Fidelma and I just published what we learned in a JHI opinion piece called Putting contact precautions in their place. In addition to highlighting the very poor evidence supporting de-implemention of contact precautions, we concluded:

"Where we implement or de-implement CPs will depend on how we frame the literature findings and our local institutional infrastructure, epidemiology, specific MDRO rates, patient factors, and institutional culture along with the local staffing and laboratory capabilities."

Jon Otter at the Reflections blog had a nice overview of our debate. He concluded:

"It was a slightly odd set-up in that Fidelma was arguing against contact precautions from a hospital that uses them, and Eli was arguing for contact precautions from a hospital that doesn’t! But I got a sense that the debaters were putting across genuine views, and not talking to a side of the debate they didn’t subscribe to. My conclusion: contact precautions make sense and fulfil the logical idea of ‘disease segregation’. The studies that seem to show stopping them makes no difference are probably explained to a large degree by the fact that they’re not done right in the first place! It was interesting that all agreed that you should apply contact precautions for the ‘really bad bugs’ (like CPE and C. difficile diarrhoea), so what is the logical difference between these and other organisms?"

Post debate, the attendees were charged with voting Against or For the motion supporting contact precautions with their feet. A fun idea!

Pre-emptive contact precautions of intubated patients: effective??

One of the odd things about contact precautions is that they are typically used to isolate patients colonized or infected with MDROs like MRSA. What this does is protect the healthcare worker from being contaminated with the MDRO but does little to protect the uncolonized patients.  The contact "event" we should MOST care about is contact between the contaminated or colonized healthcare worker and the uncolonized patient. So, current active detection and isolation programs have it all wrong. Please read that paragraph again.

Thus, I read with interest a paper just e-published in the JHI by Matsushima et al.  The authors noticed, using surveillance data, that ventilated patients in their ICU were 8 times as likely to acquire MRSA compared to non-ventilated patients.  Based on this finding they decided to place all ventilated patients on contact precautions throughout their stay to see if it reduced MRSA acquisition.  This intervention is close to a universal contact precautions intervention (or close to the STAR*ICU study that was a study of barrier precautions - gloves or gowns/gloves).

The study was completed in a 19-bed ICU in Osaka, Japan.  A unique (for the US at least) characteristic of this ICU was that only 2 rooms were single-bed rooms while the remaining 17 beds were in a single open ward. There were 2 study periods.  Period 1 occurred during 2004 and period 2 was a 3-year period from 2005-2007. During period 1, contact precautions were only used if the patients was found to be colonized with an MDRO. Surveillance cultures were obtained on all admissions and weekly using sputum, nasal and urine sources. During period 2, the same practices existed as period 1, but all patients who were intubated were placed on contact precautions for their entire stay.  MRSA acquisition occurred when a patient negative for MRSA on admission culture became positive on a subsequent surveillance or clinical culture.  They actually completed segmented Poisson regression looking for changes in slope/intercept of HA-MRSA rates. Woo woo!

The main difference between period 1 and period 2 was that many more people were placed on contact precautions during period 2. In period 1, 2.9% of patients were MRSA+ on admission and isolated while in period 2, 6.1% of patients were MRSA+ on admission, but fully 43% of patients were placed on contact precautions. Importantly, the colonization pressure was 2x greater in period 2.  Keep that in mind...

Interestingly, HA-MRSA infection in all patients declined from 3.6 to 2.3 per 1000 patient-days, p<0.05. The incidence of HA-MRSA in the intubated patients greatly decreased from 12.2% to 1.1%. I have pasted the key figure -->.  What it shows is that while HA-MRSA colonization and infection declined in intubated patients it actually slightly increased in non-intubated patients (who could be considered a non-equivalent control group).  Very cool.

Usual caveats: single center with somewhat unique bed arrangement in the ICU, and of course the control group wasn't random.  However, this is a fairly strong quasi-experimental study with good epi and statistical methods. And it points out that isolating patients actually PROTECTS them, so if there are downsides associated with contact precautions, like fewer visits from healthcare workers, at least the patients isolated directly benefit from the isolation.  This sort of study could actually help flip how we think about contact precautions. Isolate the uncolonized!

Matsushima et al. JHI 2011, doi:101016/j.jhin.2011.02.010

h/t Marin Schweizer

Do Contact Precautions Cause Depression?

STOP Contact Precautions?

Mike has written several time about his concerns for the side-effects of contact precautions. (see his kill contact precautions, personal view and adverse effects posts). His post "adverse effects" discusses Dan Morgan's systematic review that looked at the state of the literature measuring what has become dogma for many hospital epidemiologists and clinicians: contact precautions harm people. After completing this review, we weren't entirely comfortable with the literature, so we set out to complete our own series of studies seeking to assess the association between contact precautions and adverse outcomes. 

The first such study by Hannah Day, a PhD student working with Dan Morgan and me, has just been published in the March 2011 AJIC.  It was a pilot study that allowed us to gather baseline estimates to complete power calculations for the larger studies that will follow. She measured the baseline levels of depression and anxiety in patients admitted to non-ICU wards of an acute-care VA hospital. Of note: this study was a sub-study within an MRSA prediction-rule study that we'd published earlier and Dan Morgan posted on a few months ago. (see Veteran's Day MRSA post)

In 2009, 103 patients (20 on contact precautions and 83 unisolated) were approached within 48 hours of admission and received a questionnaire that included a body of questions called the HADS - Hospital Anxiety and Depression Scale. What did she find?  The HADS score was 2.2 points higher in patients on contact precautions (p=0.21).  The odds ratio for having either depression or anxiety was nearly twice as high on contact precautions (OR=1.87, 95% CI 0.61-5.69).  Yes, the study was under powered.  Intriguingly, the increased HADS scores associated with contact precautions exposure was higher in those patients newly isolated (<1 year since first isolated).

Before everyone gets too excited, what does a HADS score difference of 2.2 mean? Well, this study was too small to determine whether this increase was due to depression or anxiety.  Additionally, with the combined scale, a minimum difference of 3.0 is considered clinically significant.  Thus, even if there is an association, it may have little clinical meaning.  Finally, the HADS was measured on admission, so we were unable to determine if isolation "caused" the depression. To do that, we would need to do repeated measurements on admission and throughout the stay to see if there was a change in HADS later in the admission.  More exciting data to come...

Day HR et al. Am J Infect Control March 2011

Not to beat a dead horse, but..........

Here's another paper on adverse events associated with contact precautions. In this study from two French ICUs, 1150 patients were followed for adverse events. Outcomes for patients in contact precautions for MDROs were compared to those who were not in contact precautions. Patients in contact precautions were 1.5-fold more likely to have hypoglycemia and hyperglycemia, 1.9-fold more likely to have anticoagulant prescribing errors, and 2.1-fold more likely to develop VAP due to an MDRO.

When I read the study results I couldn't understand why there could be a causal relationship between contact precautions and anticoagulant prescribing errors. However, the authors later tell us that in these ICUs the patient charts (which are not electronic) are kept in the patient rooms.

I don't think we can blame contact precautions on the higher risk of VAP due to an MDRO. There was no higher risk of VAP due to all pathogens in the contact precautions group. Since patients found to have MDROs would be transferred to contact precautions, it only makes sense that VAP due to MDRO would be more common in patients in contact precautions.

Photo: Massachusetts General Hospital

Let me hate on contact precautions some more

The very first post on this blog was written by Dan in March 2009. It was entitled, Why I Hate Contact Precautions, vol. 1. I'll let Dan and Eli speak for themselves about how they feel now, but I remain a hater.

Results from three new studies add fuel to my fire:

(1) In one hospital, patients in contact precautions were found to wait approximately 10 hours longer for CT scans than those who were not in contact precautions. This is a reminder that there are downstream adverse effects of contact precautions that impact quality of care that perhaps we haven't even thought about.

(2) Another paper (different journal, same authors as the first paper) was a retrospective cohort study of patient safety incidents before and after patients were placed in contact precautions. Medication errors were 1.5-fold higher under contact precautions, and patient injuries were over 3-fold higher.

(3) Dan Morgan and his colleagues at University of Maryland found that patients cared for under contact precautions were twice as likely to perceive that their care was poor. Specifically, they reported poor care coordination and lack of respect for their needs and preferences.

There's an old belief shared by bartenders that nothing good happens after 2 AM. In my line of work, nothing good happens after contact precautions.

Photo: Healthcare Purchasing News

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.

Contact precautions, and why I hate them, holiday edition

Investigators at the University of Maryland (and one or two who used to be there) are among few who are carefully examining the unintentional adverse consequences of contact precautions. Their latest publication comes out in January’s ICHE. In this paper, they report an association between starting contact precautions during hospitalization and delirium.

After adjusting for comorbid conditions, age, sex, ICU status, and length of stay, Day and colleagues found that patients newly placed under contact precautions during hospitalization were more likely to experience delirium (odds ratio 1.75, 95% CI 1.6-1.9). Delirium was defined by ICD-9 code, supplemented by use of restraints and anti-psychotic meds (this measure was validated by randomly-selected chart review). Curiously, this association did not hold for patients admitted to the hospital under contact precautions. As the authors point out, those admitted under contact precautions weren’t nearly as sick as those newly placed under precautions during hospitalization, which may account for this difference.

I’ll be the first to point out that this study doesn’t prove causation—however, the study does support our previous recommendations that patients placed under contact precautions should be carefully monitored for adverse psychiatric consequences.

STAR*ICU study published: Barrier precautions not effective

It's only one study. Everybody take a deep breath. OK, exhale.

You might have already heard about this study and you might even know the results.  Someday, someone might discuss how this study was designed, and why the investigators decided to ship all of the microbiology specimens to NIH for processing resulting in a 5-day test turn-around time.  Someday, someone might explain why this study took 4 years to publish and the saga behind its eventual publication in the NEJM.  Someday, someone might even discuss how the difficulties completing this study might be hindering NIAID from funding other infection prevention clinical studies.  Someday, someone.

What can I say about the study?  Barrier precautions (ie. gloves or gowns/gloves) are ineffective in halting the transmission of MRSA and VRE in ICU settings.

Methods: The cluster-randomized trial (ie a largish quasi-experimental study but with a cool fancy name - see my "Random note" below) was completed in 2006 with the intervention lasting 6 months from March to August 2006. There were 10 intervention ICUs and 8 control ICUs.

Random note: There were 18 ICUs in this study, so it's somewhat like an 18-person RCT.  With such small numbers you can't expect that all measured and unmeasured confounders to be randomly distributed between the intervention and control ICUs. Thus, this is more like a large QE study than a standard RCT and needs to be analyzed as a QE study using multivariable regression controlling for known sources of confounding. Don't believe me? Check out Table 2 to see how different the intervention and control arms were in regards to topical and systemic antimicrobial exposure. You would not typically expect these "significant" differences in a large RCT (or large cluster-RCT).

Microbiology: Nasal swabs for MRSA surveillance cultures and stool or perianal swabs for VRE surveillance cultures were obtained from all patients within 2 days after their admission to the ICU, weekly thereafter, and within 2 days before or after their discharge from the ICU. Swabs were shipped overnight, 6 days a week, to the NIH. The mean number of days from obtaining surveillance cultures to reporting of results was 5.2 days.  I would have liked to see this reported in median days and I would also have liked this number to be reported from time of admission and not time from obtaining the culture since 2 days could pass between admission and obtaining the culture.

Planned Intervention: Known colonized or infected patients were placed on contact precautions. All other patients were placed on universal gloving from the time of admission until their discharge or until the results of surveillance cultures results returned. If surveillance cultures were positive, patients were upgraded to contact precautions (gowns/gloves) and if they were negative, they were downgraded to standard precautions.

Actual intervention as implemented: In the intervention ICUs, 92% of the ICU-days were spent under barrier precautions (51% contact precautions and 43% universal gloving) while in the control ICUs, 38% of ICU-days were spent under contact precautions.  Thus, indepedent of what anyone says, this study is about whether increasing barrier precautions from 38% to 92% reduces transmission. Also, 4 times as many patients in the intervention group were exposed to a topical antimicrobial (e.g. mupirocin), 12% vs 3.2%. Now, some will say that there wasn't 100% compliance with these interventions. I agree, this is not an efficacy trial.  As Ebb and I said in our JAMA commentary yesterday, cluster-randomized trials are real-world effectiveness trials in the domain of infection prevention.

Compliance: Overall, 47% of contacts in the intervention arm occurred with clean gloves and exit hand hygiene compliance vs 25% in the control ICUs. Compliance with contact precautions was relatively good in the intervention ICUs: gloves 82% and gowns 77%. Hand-hygiene compliance was also higher in the intervention vs. control ICUs (69% vs 59%)

MRSA or VRE colonization or infection: The mean incidence of MRSA or VRE per 1000 patient days at risk was actually higher in the intervention arm than the control arm (40.4 vs 35.6, p=0.35) but this was not statistically significant.

My thoughts:  How can this study not find a benefit when so many others have? Since most of the previous studies were uncontrolled quasi-experimental studies and we know that uncontrolled QE studies can over-estimate the measure of effect, it is possible that barrier precautions don't work.  It is also possible that other factors need to be included in any MDRO prevention program including attention to environmental cleaning and far higher compliance with the hand hygiene and contact precautions. However, the compliance rates reported in this study are not abnormally low (at least at the mean/median). Finally, perhaps decolonization is needed to achieve the results (at least for MRSA) that we've seen in other studies.

Another criticism that we've heard and will hear again is that the turn-around time for the microbiology was too-long.  This is mostly a red herring.  Since we have little evidence that gowns add much to gloves, and 92% of contacts in the intervention arm occurred with gloves, this study had FAR better glove compliance than we would expect with any typical ADI program in the real world.  The use of universal gloves in the pre-result period in the intervention arm really saved this study and, thus, it provides VERY useful information and should not be discounted. A quicker test turn-around would not have magically led to reduced transmission. Sorry.

Again, this is one study and it shouldn't be the last.  AHRQ is funding some very important MRSA (and VRE) prevention trials that many of us are involved with and I hope the publication of this paper won't discourage AHRQ (or NIH or CDC or VA) from funding these large and important studies.

What this study really tells us is that we can't fall back on legislative mandates in MDRO prevention and we must continue to search for the right combination of interventions along with developing better implementation strategies. Don't stop with the STAR*ICU study. Let this be the beginning.


Huskins W.C. et al. NEJM April 14, 2011

Don't BUGG me!

JAMA has just published the BUGG (Benefits of Universal Glove and Gown) study online (free full text here). This important, well-designed study was led by Anthony Harris (nice video of Anthony discussing the study here). It's a 9-month, multicenter, cluster randomized study in 20 medical and surgical ICUs that compares universal contact precautions (i.e., gowns and gloves for all patient care) to "standard" contact precautions (i.e., gowns and gloves for the care of patients with epidemiologically important organisms). The primary outcome evaluated was acquisition of MRSA or VRE. Patients were cultured for both organisms on admission and discharge from the ICU.

In a nutshell, the findings were as follows:

• There was no significant difference in the rate of acquisition of MRSA and VRE combined.
• When MRSA and VRE were evaluated separately, there was no difference in the acquisition of VRE, but there was a significant reduction in MRSA acquisition in the universal contact precautions group with an incremental benefit of 3 fewer MRSA acquisitions per 1,000 patient days.
• There was no difference in device-related infections (CLABSI, CAUTI, or VAP) between the two groups and no difference in mortality.
• There was no difference in adverse events between the two groups when evaluated by the IHI Global trigger tool (for what that's worth...).
• Hand hygiene rates were higher in the universal gowns/gloves study arm.
• As might be expected, there were fewer patient visits by healthcare workers in the universal gown/glove study arm.

So, how do we put this study into perspective? Should the study entice hospitals to begin universal gloving and gowning in the ICU setting? 

Let's assume you have a 15-bed ICU that admits 1,250 patients yearly with an average length of stay of 4 days (i.e., 5,000 patient-days annually). Assuming 10.5% of patients require contact precautions (this proportion comes from the control arm in the BUGG study), 131 patients would require isolation. Alternatively, under universal contact precautions, all 1,250 patients would be isolated. So by isolating an additional 1,119 patients we would prevent an additional 15 patients from acquiring MRSA (i.e., 3 per 1,000 patient days). Assuming 20% of the colonized patients go on to develop infection, 3 additional MRSA infections would be prevented with universal contact precautions. Bottom line: to prevent 3 additional infections we needed to isolate an additional 1,100 patients. Given that I'm a utilitarian and that I believe that the burden of contact precautions on patients is high, my assessment is that the benefit of universal gloves and gowns is outweighed by the overall burden on patients. Now it's true that MDR-GNRs and C. difficile weren't evaluated in the study so we may not be evaluating the full benefit of the intervention. But for now, don't BUGG me--I'm still pushing universal chlorhexidine bathing, high rates of hand hygiene compliance, and no isolation of patients with MRSA or VRE.

Addendum (10/6/13):  More on this study in Time.

Photo: Duke Infection Control Outreach Network (DICON)

Killing contact precautions one study at a time

Dan Uslan's group at UCLA has just published a new paper in Infection Control and Hospital Epidemiology on the elimination of contact precautions for MRSA and VRE at their health system (2 hospitals).

They looked at the rate of positive clinical cultures for MRSA and VRE one year before and after contact precautions were stopped on July 1, 2014. Importantly, at around the same time they expanded daily chlorhexidine bathing from ICU patients to all inpatients.

Comparing the pre- and post-intervention periods in this quasi-experimental study, here are the key findings:

• There was no difference in the rate of clinical cultures for MRSA or VRE.
• There was no difference in C. difficile infection rates (a nonequivalent dependent variable).
• There was no difference in MRSA colonization rates (active surveillance cultures were performed on high-risk patients).
• An annual cost savings of $730,000 in isolation gowns, and $5 million in nursing time associated with donning personal protective equipment was demonstrated.

Now one could argue that the benefit of contact precautions was replaced by the beneficial effect of chlorhexidine bathing. That doesn't bother me. I'd gladly trade 24 hours of gowns, gloves and confinement to a small space for a 5-minute wipedown with chlorhexidine. 

This is the fourth paper that shows a consistent finding of no increase in MDRO infections after contact precautions are stopped. The others can be found here, here, and here. And there are two more studies in abstract form. It seems to me that we simply don't need contact precautions for MRSA and VRE given newer developments in infection prevention (chlorhexidine bathing, better compliance with hand hygiene, private patient rooms, and enhanced environmental disinfection). Hopefully, the addition of this new study will convince other hospitals that the world doesn't end when contact precautions are retired.

Photo:  Dan Uslan MD, UCLA

Questions for Contact Precautions Eliminators

Over the past eight years, I've been the lone supporter of contact precautions on the blog. Of course, Tom and Hilary haven't publicly committed either way, at least on this blog. And to clarify my position, I'm greatly in favor of more studies examining the role of isolation strategies and how/where to best implement them. For example, do we need gowns or would gloves alone suffice? And should we isolate uncolonized patients instead of colonized patients since we're most interested in preventing transmission from contaminated healthcare worker to uncolonized patients? This latter question is why I currently favor exploring the benefits of universal gloving strategies. But of course, there is a growing number of studies that explore the discontinuation of contact precautions, which have led to places like Iowa eliminating contact precautions for MRSA/VRE colonized or infected patients. So with that in mind, I have a few questions for folks who are in favor of eliminating contact precautions. Specifically, I want to understand the who/what/when/where/why behind their recommendations.


Question #1: Are hospitals no longer a source for MDRO-bacterial acquisition? Do acute care hospitals or subpopulation (ICUs, hemodialysis) remain sites for patient-to-patient transmission or have we completely eliminated transmission in these settings?

Question #2: If transmission has been eliminated, how would we know? Are you aware of data that proves patients who are uncolonized on admission remain uncolonized by the time of discharge? Does your hospital do discharge surveillance cultures for sentinel organisms like MRSA, CRE?

Question #3: If you don't do surveillance culturing on discharge, do you follow patients post discharge to make sure they don't develop an MDRO infection at a subsequent point? Do patients no longer develop MDRO infections linked to a prior hospital stay suggesting that all transmission is now occurring in the community setting?

Question #4: If transmission in acute-care settings has been eliminated, how has that happened? Is it that hand hygiene compliance of 34 to 57% is enough to halt all transmission? Is it that the environment is so sparkling clean these days that clinicians can't even pick up bad bacteria on their hands?

Question #5: Perhaps you agree that hospitals (or ICUs) are still engines powering the emergence of MDRO in human populations and your hospital might even be a source for patient acquisition. Is it that you think hands are not a source of transmission and contact precautions just don't work? Do you feel similarly about hand hygiene - does hand hygiene not reduce transmission? Since we know that when caring for patients that healthcare workers gloves/gowns become contaminated 8-39% of the time, where do these bacteria go? Do they just disappear?

Question #6: Finally, even if transmission is occurring via the hands of healthcare workers maybe you're convinced it's not your problem? If you can't see the benefits directly in your hospital, it's not important. Tragedy of the commons? - meh. Perhaps, it's up to me to detect all MRSA colonized patients in my clinic or on admission to my hospital and decolonize them?

It's not about you. Really. Well, most of you

After my posts discussing construct validity and other issues with studies attempting to understand the effect of eliminating contact precautions, several folks expressed concern that I was specifically talking about their proposed study, published study, abstract or hospital.  Well, I can assure you that none of my recent posts are about your studies or hospitals. Well, expect one, but not the one you might be thinking about.

While it's true that there have been many notable back and forth discussions about contact precautions on this blog from its initiation, I greatly respect Dan’s and Mike’s right to implement infection control in their hospital, their way. For example, we might even agree that contact precautions reduce transmission of MRSA by a certain amount; however, they might decide that MRSA is rare enough in their hospital that contact precautions are not locally cost-effective. I might even agree. Others colleagues have been concerned that I’m commenting on their specific study including ones presented yesterday at ICPIC. Yet, I never attended the session where several studies of ESBL control methods were presented. Unfortunately, jet-lag prevented me from making the earliest session, so I can’t claim specific knowledge or concerns about those studies.

However, I will share what prompted my recent posts (and hopefully a few more). A few weeks ago I had the opportunity to hear about a planned study that will examine the effect of discontinuing contact precautions. This planned study is large, includes a diverse set of hospitals and has a randomized design. However, the study only plans to discontinue contact precautions in non-ICU settings and only track clinical cultures. So, in my opinion, the study has strong generalizability, good internal validity but very poor construct validity.

During the discussion of the planned study, I mentioned this issue. The PI on the study was very quick to say that sure, it's not a perfect study but isn’t some information better than nothing? Of course the PI knows that it is hard for other scientists to say no to that question. We all like data. However, in this case the answer is a resounding no. Any large study will have economic and other impacts. For example, one opportunity cost of funding a large study with poor construct validity is not funding another study that could have a stronger design. Additionally, if you aren’t measuring the outcome properly, how can you tell if your intervention is harming patients? This is a human subjects issue, potentially. So, hopefully they will add methods that can measure colonization on discharge or better yet track post-discharge infections.

There you have it. You can be assured that I wasn’t thinking about your study or hospital. Of course, I can’t promise the same in the future.

Are we ready to kill contact precautions?

Pauline Chen, in her New York Times column, Doctor and Patient, takes on contact precautions this week. Her piece, When Isolation Hampers More than Bacteria, is one of the first in the mainstream media to point out the unintended consequences of contact precautions. This has been a recurring theme on our blog. In one of the very first postings on this blog, Dan wrote a piece entitled, Why I hate contact precautions. Just this week I was asked by a concerned medical student to review the case of an elderly man hospitalized for over 3 months and confined to a lonely hospital room because a nasal swab grew MRSA. "Can't we just allow him to sit in the hallway?" asked the student. And we figured out a way to do that. Dan Morgan states in Chen's piece: “There is a misperception that infections are the single worst adverse event that can happen in a hospital.”  Also quoted in the piece is my colleague, Gonzalo Bearman, regarding our studies comparing universal gloving and contact precautions, which found no difference in infection rates when the two strategies were compared. Maybe it's finally time to think about moving beyond contact precautions.

Moving away from contact precautions

Yesterday, Dan posted on the new study by Dan Morgan and others at the University of Maryland that points out yet again that contact precautions have an impact on care received by inpatients. Over the past year or so, I began to wonder about scaling back contact precautions. My colleagues, Gonzalo Bearman and Mike Stevens, recently published a paper on considerations for reducing contact precautions. Our hand hygiene rates have been >90% institution-wide for 3 years and we conduct surveillance hospital-wide for all device-related infections. And we've continued to focus on horizontal infection prevention strategies, such as chlorhexidine bathing, which we do for all ICU patients, and more recently for non-ICU patients with devices in situ. Thus, it seemed as though it was time to bite the bullet. We are now rolling out a new policy in which MRSA and VRE infection and colonization no longer require contact precautions. We'll still continue contact precautions for multidrug resistant gram-negatives, C. difficile, and ectoparasitic infestations. Feedback from healthcare workers has been very positive. And I bet we'll also make some patients happy. It should also produce less waste--we currently use 1.3 million disposable plastic gowns yearly!

Photo: Stericycle

Why I hate Contact Precautions, vol. 1.

Because they hurt patients. And yes, I know that using barriers can be essential to controlling outbreaks of bugs that are spread by direct contact.....but somehow the use of contact precautions has become embedded in our standard practice for managing any patient found to carry a resistant organism, whether or not they have draining wounds, uncontrolled secretions, etc.--even in non-outbreak settings.

But the evidence to support use of contact precautions outside of outbreak settings is weak. Not only that, but the implementation of contact precautions in most hospitals is even worse than that of hand hygiene.

Why am posting this? Because Kathy Kirkland, hospital epidemiologist at Dartmouth, has a great piece in the March issue of CID that proposes a new approach to the use of contact precautions. I suggest that you read it.

Are contact precautions headed for extinction?

There's an interesting letter in the latest Clinical Infectious Diseases from Dan Morgan and Kathy Kirkland on contact precautions. They surveyed 34 infectious diseases physicians at a meet-the-professor session at the 2011 Infectious Diseases Society of America Meeting. Interestingly, only 38% believed that contact precautions prevent transmission of multidrug resistant organisms, and 74% felt that contact precautions may actually harm patients. The sample size of the survey was small and perhaps there's bias in that the participants had selected to attend a session on contact precautions, but the findings are intriguing. I suspect that some day in the future people will find photographs of healthcare workers wrapped in plastic as weird as we now find the plague doctor outfit.

Photo: Grim Reviews