The predictive capacity of toe blood pressure and the toe brachial index for foot wound healing and amputation : a systematic review and meta-analysis

Foot wounds are a growing international concern, as the incidence of risk factors such as diabetes, obesity, vascular disease and advancing age rises. This systematic review and meta-analysis was performed to determine the prognostic capabilities of toe blood pressure and the toe brachial index for predicting chronic foot wound healing or progression to amputation. MEDLINE, CINAHL, EMBASE, PubMed Central and the reference lists of retrieved studies were systematically searched in June 2014. Two authors independently reviewed selected studies reporting original research. Methodological quality was assessed using STROBE and CASP appraisal tools. Ten studies were reviewed; six investigated wound healing and four investigated amputation as the outcome. Study quality was inconsistent; most failed to report aspects of their methodology and used different equipment or techniques. Meta-analysis indicated a cut-off toe blood pressure of 30 mmHg was associated with a 3.25 (95% CI: 1.96, 5.41) times greater risk of non-healing; however, significant heterogeneity was found. Additionally, serial assessments or grading of toe blood pressure values may improve accuracy and utility. Toe blood pressure and related indices may be useful in predicting the outcome of chronic foot wounds; however, further high-quality research is required before clinical utility is confirmed.