Cross-sectional correlations between the toe brachial index and lower limb complications in older people

The aim of the study was to investigate the relationship between the toe brachial index (TBI) and foot ulceration and amputation in older people. Two hundred and sixty-one participants meeting guidelines for lower limb vascular assessment had their toe and brachial blood pressure measured, medical records audited and signs and symptoms of peripheral arterial disease (PAD) recorded. Pearson's correlation and linear regression analyses were performed to determine the strength of relationships between variables. Significant correlations were found between the TBI and painful symptoms (r = −0·35, P < 0·05) and foot complications (r = −0·31, P < 0·05). After adjusting for traditional risk factors for foot complications, participants with a TBI <0·70 were 19 times more likely to have a history of foot wounds or amputation (odds ratio = 19·20, 95% confidence interval (CI): 2·36–155·96, P < 0·001) than those with higher TBI values (>0·70). This preliminary study supports a TBI threshold of 0·70 for PAD diagnosis and indicates that lower values are associated with painful symptoms, history of ulceration and amputation. Future longitudinal investigation of the predictive capacity is now warranted.