Classification systems for lower extremity amputation prediction in subjects with active diabetic foot ulcer: a systematic review and meta-analysis.

AIM: We systematically review the available systems used to classify diabetic foot ulcers in order to synthesize their methodological qualitative issues and accuracy to predict lower extremity amputation, as this may represent a critical point in these patients' care.
MATERIAL AND METHODS: Two investigators searched, in EBSCO, ISI, PubMed and SCOPUS databases, and independently selected studies published until May 2013 and reporting prognostic accuracy and/or reliability of specific systems for patients with diabetic foot ulcer in order to predict lower extremity amputation.
RESULTS: We included 25 studies reporting a prevalence of lower extremity amputation between 6% and 78%. Eight different diabetic foot ulcer descriptions and seven prognostic stratification classification systems were addressed with a variable (1-9) number of factors included, specially peripheral arterial disease (n = 12) or infection at the ulcer site (n = 10) or ulcer depth (n = 10). The Meggitt-Wagner, S(AD)SAD and Texas University Classification systems were the most extensively validated, whereas ten classifications were derived or validated only once. Reliability was reported in a single study, and accuracy measures were reported in five studies with another eight allowing their calculation. Pooled accuracy ranged from 0.65 (for gangrene) to 0.74 (for infection).
CONCLUSION: There are numerous classification systems for diabetic foot ulcer outcome prediction, but only few studies evaluated their reliability or external validity. Studies rarely validated several systems simultaneously and only a few reported accuracy measures. Further studies assessing reliability and accuracy of the available systems and their composing variables are needed.