In their article, Boyko et al. (1) describe a foot ulcer prediction tool that will be useful in practice, as it is based on simple clinical criteria. The tool is well validated but limited by the patients examined, who were predominantly male (98%), mainly with type 2 diabetes, and were recruited from a hospital diabetes clinic. We have already addressed these problems in a previous publication (2) using a similar, clinically focused foot ulcer prediction tool (3) that included many of the criteria recommended by the International Working Group on the Diabetic Foot (4). Our grading scheme categorized 3,526 patients into low, moderate, or high risk of ulceration. High-risk patients “were 83 times more likely to ulcerate than low risk” patients, and the chance of “low-risk” patients remaining ulcer-free after 2.4 years was 99.7% (2). This tool was valid for type 1 and type 2 diabetic male and female subjects in a population-based cohort. Such foot ulcer prediction tools are thus useful for “all-comers” in a general community setting, as well as in specialized hospital clinics.
Boyko et al. also raised the issue that patients at high risk of ulceration may be at increased risk of death. We demonstrated that the crude mortality rate for high-risk patients was 19.1% compared with 3.4% for low-risk patients (2). Thus, high risk of ulceration is associated with increased death rate as suspected by Boyko et al., which may result in an underestimation of the predictive value of these clinical tools, as patients may die before they develop foot ulcers.
These two studies complement each other by demonstrating that the overall foot ulcer risk assessment is greater than any individual criteria (1) and that the tool is valid in routine clinical practice for all patients in the community (2) and specialized centers (1,2). Foot ulcer prediction tools may be useful in directing educational initiatives and scarce health care resources to those at greatest need.
