A new Australian study surveying Infectious Diseases (ID) Consultants from right around Australia and New Zealand has found that diabetic foot infections (DFI) make up 20% of all their work and DFIs are managed very differently between consultants. But, as we always say is that the full story?
This study published in the Journal of Foot and Ankle Research was led by DFA’s friends Dr Rob Commons, Dr Ed Raby and the Diabetic Foot Infections Australia New Zealand (DEFIANZ) network. DEFIANZ was established in response to DFI being found to be in the top-5 research priorities by the Australasian Society of Infectious Diseases. And this study is the first from this exciting new network.
What do we know about diabetic foot infection?
Readers of our summaries would know diabetic foot infections (DFIs) are a massive deal in the world of diabetic foot disease. We have recently summarized studies showing that nearly all DFIs originate in diabetic foot ulcers, 40% of non-infected diabetic foot ulcers will get infected and at any one time around half of all diabetic foot ulcers are infected. We also know that DFIs cause the largest proportions of diabetes-related hospitalizations and amputations in Australia and around the world.
Yet, there are international diabetic foot infection guidelines out there for us to follow and improve these DFI outcomes, but they are also based on very few RCTs. In Australia we typically use the international guidelines for assessment and the Australian Therapeutics Guidelines for management. But, what we don’t know is how our most expert infection doctors managed DFI and is DFI a massive deal to them. That was until this new study from DEFIANZ.
What did this new study do then?
The authors of this study essentially developed a survey to try and find out how many DFI patients do ID Consultants see each week, what access to other diabetic foot services do they have, how do they typically manage patients with DFI and do they follow DFI guidelines recommendations.
This 36-item survey was based on a survey used to find out Australian podiatrists’ management of diabetic foot disease and customized for ID consultants by the DEFIANZ group. Once the DEFIANZ group of nearly 20 members were all happy with the survey, it was then sent via email to the 499 registered ID Consultants and Trainees in Australia and New Zealand (NZ) to complete over one month.
So what did they find?
Overall, 142 (28%) of the 499 registered ID Consultants and Trainees replied to the survey. Of those that replied 75% were from Australia and 70% were Consultants. Firstly, from those who replied, they found DFI consults made up 19.2% of all ID consults in an average week and this was pretty much the same for Consultants, Trainees, different nations and settings.
Secondly, nearly all who replied typically saw DFI patients in both public hospital inpatient (98%) and outpatient settings (83%), but few saw them privately (19%) or via telehealth (3%). Most had direct access to a multi-disciplinary diabetic foot team (78%) and they were part of this team (73%). And nearly all had direct on-site access to other DFI-related services, including diabetes (99%), parenteral antimicrobial therapy (99%), podiatry (94%), offloading (90%) and vascular surgeon services (88%).
Thirdly, most (76%) reported they would treat patients with a mild or moderate DFI with the antibiotics recommended in the Australian Therapeutic Guidelines most of the time. But, when they were asked to recommend antibiotic treatment for a specific scenario of a patient with a moderate DFI, they responded with 82 different antibiotic treatment recommendations for treating that one patient. This included different combinations of antibiotic drugs, administrations and durations. Similarly, when recommending antibiotic treatment for the other specific scenario of a patient with osteomyelitis, they responded with 76 different antibiotic treatment suggestions. Conversely, for these scenarios most (80%) recommended the same guideline-recommended MRI imaging to diagnose osteomyelitis though.
What was good or not so good about this study?
While this study had many strengths – i) the survey reached all registered ID Consultants and Trainees, ii) it had a reasonable response rate for a survey of this type of nearly 30%, iii) the survey was based on a survey already used for a similar purpose, and iv) was briefly tested on DEFIANZ members to make sure it was suitable – it wasn’t without limitations. These limitations included: i) the survey wasn’t tested for reliability or validity, ii) there is a high chance of response bias meaning those interested in DFI were probably more likely to complete the survey which might overestimate actual practice, iii) they used two scenarios to see how ID consultants managed patients which isn’t entirely the same as real life practice and iv) they used a lot of Likert scales for answers to questions which can be a little imprecise.
So what does that all mean?
Well the authors sum it up nicely by concluding, “This study found nearly one in every five consultations provided by Australian and New Zealand ID Physicians and Trainees were for patients with DFI, and that the treatment recommended is heterogeneous (very different from each other).”
These findings in combination with similar previous Australian findings show that DFI management makes up a large proportion of an ID Consultants caseload. ID Consultants also seem to have good access to the guidelines and multi-disciplinary DFI-related services necessary to manage these patients. They also seem to consistently use the recommended imaging. But, when it comes to recommending antibiotic treatment for a patient they were all different with their recommendations.
So why on earth is that we hear you ask? Well the authors propose a number of valid reasons: i) lack of interest in DFI and thus awareness and training in the exact evidence-based guideline recommendations, ii) the complexity of DFI patients mean consultants may not be able to follow guideline recommended antibiotic treatments because DFI patients often have comorbidities that may prevent this, iii) poor DFI outcomes are often blamed on ‘wrong’ antibiotic treatment meaning ID consultants may overcompensate and treat patients for longer with stronger antibiotics than recommended, and iv) perhaps most importantly there is a lack of high quality clinical RCTs into DFI.
Which leads us to their recommendations to improve this situation, “the study highlights the need for outcome-directed randomized clinical trials. Patients with DFI currently form an integral part of an ID Physician’s practice and because this is likely to increase in the future, the ID community needs to continue to recognize the importance of DFI as a significant component of ID practice and training.”
What is our final words on this study?
This study confirms that DFI is a very common, complex and costly medical condition. It also highlights that much more needs to be done in terms of training doctors in evidence-based DFI treatments, and research to improve the DFI treatments we have available. If that all sounds familiar that’s because this is exactly what is also in the recently released Australian Diabetes-Related Foot Disease Strategy 2018-2022: The first step towards ending avoidable amputations within a generation.
And speaking of more DFI research watch out for the next DEFIANZ study: the Diabetic foot INfection lonGitudinal Outcome study (DINGO). Now this means that if you see a DINGO at your hospital in future, it won’t be holding a baby, but it just might be holding the key to future DFI treatments so in this case please help it as much as you can for the future benefits of our patients with DFIs.