The role of footwear in the prevention of foot lesions in patients with NIDDM. Conventional wisdom or evidence-based practice?

OBJECTIVE

To conduct a prospective evaluation of footwear characteristics as predictors of diabetic foot wounds.

RESEARCH DESIGN AND METHODS

A total of 352 patients with NIDDM enrolled in a randomized controlled trial aimed at preventing diabetic foot lesions in an academic general medicine practice were studied. Foot wounds (n = 63) were modeled univariately and multivariably using generalized estimating equations. The dependent variable was a wound classified as a 1.2 or greater according to the Seattle Wound Classification System, indicating at least a superficial or healing minor lesion with no functional interruption of the protective cutaneous barrier. Independent variables included detailed measures of style and material of patients' indoor and outdoor shoes, appropriate length and width, sock fibers, whether the patient had bought new shoes in the past 6 months, and if the patient had been recommended for special shoes. Modeling controlled for intervention status and physiological measures (baseline wound, monofilament abnormalities, and serum HDL level).

RESULTS

Initial screening (P < 0.20) suggested that a recommendation for special shoes, shoe length, and shoe width were indicative of wounds at follow-up (odds ratios [ORs] 2.19, 1.84, 1.86, respectively), while having bought shoes in the past 6 months was associated with no wound at follow-up (OR 0.60). The final multivariable model included only the recommendation for special shoes (OR 2.19; 95% CI 1.07-4.49).

CONCLUSIONS

Many variables commonly cited as protective measures in footwear for diabetic patients were not prospectively predictive when controlling for physiological risk factors. Rigorous analyses are needed to examine the many assumptions regarding footwear recommendations for diabetic patients.