Ankle brachial pressure index was measured in a standard manner using both PPG and Doppler probes. For PPG-ABPI, a PPG probe was placed on the index finger and great toe, and a microcomputer determined the ABPI. These values were compared with the ABPI measured manually using an 8-MHz Doppler probe. Correlation and agreement between PPG and Doppler ABPI were assessed by Lin's correlation coefficient and Bland-Altman plots.