Objective assessment for digital clubbing in Caucasian, Negro, and Oriental subjects.

The ratio of the depth of the index finger at the base of tbe nail (DPD) divided by the depth at the d i i interphalangeal joint (IPD) has been reported useful in evaluating subjects for the presence of digital clubbing. A ratio which exceeds 1 has been considered abnormal. This relationship was independent of age and sex. To determine whether the ratio of DPD/IPD was independent of race, measurements were made of casts of the index fingers of 80 normal subjects: 20 North American Caucasians, 20 Iranians, 20 Negroes, and 20 Orientals. No significant diierence was found among mean ratios of North American Caucasians, Negrws, and Orientals. A significantly h e r mean ratio in Imhm as compared with Negroes may have been related to the method of selection of the former group. It is concluded that the ratio of DPD/IPD is probably independent of race. These observations further conlirm the ratio of DPD/IPD as a method useful in assessing the presence of digital clubbing.