Is health literacy linked with diabetic foot outcomes?

Results of a systematic review on health literacy in people with diabetic foot disease has recently been presented in the prestigious Diabetic Medicine journal and at the 8th International Symposium on the Diabetic Foot held at The Hague in May this year. This large review investigated the association between health literacy and diabetic foot disease outcomes and was led by the University of Tasmania’s Pam Chen – President of the Advanced Practicing Podiatrists-High Risk Foot Group, emerging (inter)national diabetic foot researcher and member of the Aussie contingent that came 5th in the Diabetic Foot Olympics.

What do we know about health literacy?

Health literacy is defined as “the cognitive and social skills which determine the motivation and ability of individuals to gain access to, understand, and use information in ways which promote and maintain good health”. It has been found to be lower in people with diabetes with some studies showing links between health literacy and developing complications, such as retinopathy and stroke. In people with diabetes an understanding of the diabetes process, it’s potential consequences and how to prevent them is particularly important, as diabetes is a disease that requires a lot of self-care to prevent complications. This also makes sense when it comes to people with diabetic foot disease, as these people require an even greater level of understanding on how diabetes affects their feet and a greater level of preventative self-care behaviour to prevent poor outcomes (e.g. checking wounds, wearing offloading devices etc.)

What did this study do then?

This systematic review aimed to determine if health literacy is associated with diabetic foot disease and foot care behaviours. The review was registered appropriately in PROSPERO and its results were reported according to this international best practice standard. The review systematically searched, and quality assessed, all the relevant previous research in this area. It found 16 studies in the field with most being cross-sectional studies from the US that focused on the relationship between health literacy and foot self-care behaviours. Only a few studies investigated the relationship between health literacy and those at risk of or with diabetic foot disease. And most used a fairly narrow measure of health literacy. Once the articles were selected and quality assessed, relevant data was pooled and reported in separate meta-analyses.

What did they find?

The results of the systematic review focused on the association between health literacy levels and three main outcomes: 1. diabetic foot disease (ulcers, amputations), 2. risk factors for diabetic foot disease (peripheral neuropathy and peripheral arterial disease), and 3. foot self-care behaviours. Firstly, for diabetic foot disease. They pooled the findings from 2 studies with a combined 1,278 patients and found that people with “inadequate” health literacy were twice as likely to develop diabetic foot disease, but this was not statistically significant. The authors concluded though that the results can’t exclude an association between health literacy and diabetic foot disease as there were too few studies.

Secondly, for various risk factors. For peripheral neuropathy, the authors were able to pool the findings of 2 studies with 399 patients and found no significant difference in health literacy levels between those with neuropathy and those without. However, interestingly, when the authors contacted the authors of previous studies and added in further unpublished data the data suggested lower health literacy levels for people with neuropathy. For peripheral arterial disease, only one study was identified with 998 people which found lower levels of health literacy in people with intermittent claudication. So, when it comes to the links between health literacy and risk factors the jury is still out.

Finally, for foot self-care behaviours there were many more studies. Seven studies were identified with 1033 patients. However, when pooled no association was found between health literacy and foot-self-care behaviours. It is worth noting that in those 7 studies the measures of foot-care behaviours were rather limited, mainly relying on a couple of questions on the established but general diabetes Summary of Diabetes Self Care Activities scale. This may be a factor in this finding.

What was good and not so good about this study?

There were many good things about this systematic review, including it adhered to best practice international reporting of systematic reviews, performed objective quality assessments and pooled relevant papers into different meta-analyses. Perhaps the not so good things were the limited and mostly cross-sectional studies they were able to find and pool which really reflects the major gaps in knowledge in this field.

What does that all mean?

Although the findings generally showed no clear pattern of association between health literacy and aspects relating to diabetic foot disease, an association cannot yet be excluded based on the limited data available. And therefore, future well-designed longitudinal studies are required. Whilst we know it can be boring to read in well-designed systematic reviews, that “future research is required”, this finding is still significant. It is significant because it highlights that there is still much work to do to get a clear understanding of the role health literacy plays in our population, and it is terrific to read about Australian research in this area. As the authors point out, our patients have a condition that has a huge impact on many areas of their health, as they need to use their health literacy skills to absorb, interpret and act on information about their condition. If stronger evidence emerges from well-designed studies, then potentially effective interventions can be designed and tested.

Where to from here?

The psycho-behavioural aspects of diabetic foot disease is a fast-emerging area of research, and the work by Pam and colleagues significantly adds to this literature. The International Symposium this year reflected the need for much more research in this area by highlighting it as the focus of their opening keynote presentation, entitled “New Trends in Diabetic Foot Ulcer Research: From Biology to Psychology”, by Professors Andrew Boulton and Loretta Vileikyte. There were also key workshops on the topic by renowned psychologist Professor Jeffrey Gonzalez, and several other oral and poster presentations as well, such as Pam’s work. This new focus and new systematic review highlights the problem and dilemma clinicians have in assisting their patients’ understanding, perceptions, health literacy and behaviours, especially as self-care behaviour is so important in preventing foot disease outcomes. And it is obvious from this review that more high-quality research is needed in this field if we are to optimize our patients care.

And we are very happy to say that Pam and her team are well on their way to reporting on such needed high-quality research with their next study, the SHELLED study. Pam presented baseline findings from this 4-year longitudinal Southern Tasmanian Health Literacy and Foot Ulcer Development in Diabetes Mellitus (SHELLED) study at the International Symposium in the Hague which generated much interest.

And fortunately for us, Pam will be presenting a keynote presentation at DFA 2019 on her latest SHELLED findings amongst other health literacy studies, entitled “Health Literacy and Diabetic Foot Disease: Simple communication is no mean “feet””! And with great timing and too whet your appetite, the first of many of Pam’s SHELLED articles was literally just published here.

So simply if you want to know how to talk to feet, come to DFA 2019 and hear from one of the world’s best “foot whisperers”, our very own Pam Chen ????.

By Dr Byron Perrin