Cognitive dissonance, and turning evidence into behaviour change in antibiotic stewardship

I was walking down a corridor at the hospital today and bumped into one of the urology consultants. He thanked me for some advice I'd given him last week for a patient with a prosthetic valve undergoing a urological procedure. He had thought that prophylaxis wasn't indicated (we had talked about this on a previous occasion, and he knew I'd said quite firmly that it was or wasn't indicated - he just couldn't remember which!). However, his colleague was adamant the patient should be given an antibiotic. So I had reminded him about the NICE guidance which essentially says that there is no evidence for it, and does not recommend it. The trouble with this advice is that it appears rather sterile (if you forgive the pun) in relation to the thought that you might give the patient in front of you a potentially fatal disease (endocarditis). It is especially hard to stop doing something that you have successfully being doing all your working life ie. not giving patients endocarditis, which you have correlated with giving them a pre-procedure antibiotic. So this sets up some cognitive dissonance - your brain is trying to hold two competing views, one in which antibiotics are good (and which chimes with everything you have previously said and done) and one in which antibiotics are bad (which implies that you have been wrong for the last 20 years). It is then a natural reaction to try to dismiss the thing that says you were wrong. We can do this in many ways, from attacking the basis of the evidence, to just forgetting about it. This is why rational cases for behaviour change rarely work. So we need to find ways to address this.

And this is where the conversation became more interesting. He went on to say that the thing that made him remember the 'right' answer, and feel confident that it was OK to withhold antibiotics, was me saying that everyone is bacteraemic whenever they brush their teeth. So if you are going to give antibiotics for this procedure then you should probably consider giving them everytime you brush your teeth. This information allowed him to create an alternative narrative that had equal mental validity with his prior experience. My advice could now sit comfortable in his mental model of the world.

I had a similar experience today when reviewing the latest NICE guidance on the relative risks of different antibiotics for causing C difficile. Not unexpectedly, 3rd generation cephalosporins are high risk. I was pleased to see carbapenems as quite high risk (this is what I wanted to hear). I was also pleased that first generation cephalosporins are low risk, while co-amoxiclav is high risk (we somewhat controversially recommend cefalexin as first line oral option for pyelonephritis in the community). So that was all good. But then trimethoprim came in at high risk. Not what I was expecting, and not what I really wanted to see as it starts to challenge the order of antibiotics we recommend for many infections. My response? I have ignored it. Well, not quite, but I know that I don't believe it. The only way I would believe it is to be taken to the cases of patients who had a clear diagnosis of C diff, and then to be shown the offending trimethoprim prescription. And then for this process to continue until basically my mental model collapsed and I had to rebuild a new truth.

And here we see two powerful ways of tackling dissonance. One is to provide a story which has sufficient power to immediately override prior assumptions. This can be a new piece of evidence, or it could be a single highly emotional patient history. The other way is to take people to the data, and show them it until they accept its validity and their defences collapse. But they have to do this for themselves - meta-analyses will never work.

So in that spirit, I have started adding some statements to some revised UTI guidelines we are writing. This is also bearing in mind the comments of Alison Holmes at the recent ECCMID conference, that we need to talk much more about general principles of stewardship, and worry much less about specifics. The idea is to try to find things that may have the power to immediately shift people's view of the world. This is normative change. Here are some starters - some are general things, some are specific to our local guidelines. I would love to hear some feedback on these, and please feel free to contribute more.

Single doses of antibiotics are often effective

A single dose of any antibiotic is an effective treatment for UTI in most patients. Therapeutic concentrations will be reached for at least 12-24 hours. This is sufficient to achieve cure in over two thirds of patients.

This has been shown for acute cystitis using the following agents:

Amoxicillin     Harbord RB et al (1981) BMJ 283, 1301-2

Septrin             Gossius G (1984) Scand J Infect Dis 16, 373

Quinolones      Saginur R et al. (1992) Arch Intern Med152 1233-7
Tetracycline    Rosenstock J et al (1985) Antimicrob Agents Chemother. 27 652-4

Nitrofurantoin  Gossius G (1984) Curr Ther Res 35, 925-3

Cefaclor          Greenberg RN (1981) Am J Med 71, 841-5

 A single dose of an antibiotic, initiated by the patient when first symptomatic, is effective in recurrent UTI

                                   Wong ES (1985) Ann Intern Med 102, 302-7

UTI symptoms may resolve spontaneously

Up to 50% of women with UTI symptoms recover spontaneously within a week

                                    Mody L (2014) JAMA 311, 844-54

What do others do when trying to diagnose infection in elderly patients with vague symptoms?

A negative dipstick (no nitrites or pyuria) effectively rules out infection in elderly women

                                    Mody L (2014) JAMA 311, 844-54

It is reasonable to observe elderly patients with non-specific symptoms, while correcting hydration and reviewing medication. If, after 24 hours, an infection remains possible, then a dipstick may help in deciding whether to send an MSU, and this result may then guide treatment.

                                    Mody L (2014) JAMA 311, 844-54

 

What is wrong with using dipsticks in catheterised patients?

Dipsticks are completely pointless in catheterised patients.  Even with the best catheter care, 1 in 20 catheters will become colonised with bacteria every day. Long term catheters are almost all colonised with bacteria. Culture is only useful in detecting resistant bacteria, not in making the diagnosis.

Breitenbucher RB (1984) Arch Intern Med144 1585-8

What are the best antibiotics to treat UTI?

 

It is not necessary to cover enterococci in empirical UTI treatment protocols. Cephalosporins and quinolones do not treat enterococci, but are well researched options to treat pyelonephritis as single agents. Gentamicin has been shown to be a good single agent option to treat pyelonephritis

Wie SH (2014) Clin Microb Infect 20, 1211-8

Cefalexin is an effective treatment for UTI in North Devon and is relatively low risk for causing C. difficile. Sensitivity data shows approximately 9 out of 10 UTIs in North Devon. It is not associated with C difficile (unlike 2^nd and 3rd generation cephalosporins, co-amoxiclav or ciprofloxacin)
Clostridium difficile infection: risk with broad-spectrum antibiotics. NICE 2015

What are the downsides of prescribing abx?

Antibiotic resistance is a predictable and very common adverse drug reaction.

Resistant pathogenic bacteria can be detected in one third of patients after antibiotic treatment in hospital.

Gorska et al (2015) ECCMID O001 oral session

Your normal flora might be worth looking after. They may prevent more serious infection :Mice challenged with S. aureus a week before being given influenza are MORE like to survive

Guery et al (2015) ECCMID O001 oral session

Your normal flora might be worth looking after, particularly in children. They may promote a more normal inflammatory response to allergens in the lung, perhaps reducing the risk of asthma. Guery et al (2015) ECCMID O001 oral session

Your normal flora might be worth looking after. Abnormal bacteria in the gut have been associated with many diseases, from obesity to Crohns disease.  Antibiotic treatment induces profound effects in metabolism. Perez-Cobas (2013) Gut 62, 1591

Every dose of antibiotic is a role of the dice - there is a chance that beneficial bacteria may be lost; and harmful bacteria may be gained. The effects of ciprofloxacin are unpredictable, and may sometimes be profound and long lasting, and of unknown physiological relevance Dethlefeson (2011) PNAS108, 4554