Multicenter study on finger systolic blood pressure test for diagnosis of vibration-induced white finger

A multicenter study (six Rosai hospitals around Japan) was performed to investigate the diagnostic value of changes in finger systolic blood pressure (FSBP) after segmental local cooling for vibration-induced white finger (VWF).

Subjects were 154 men without exposure to vibration and 135 men with occupational vibration exposure. They were classified into four groups: Group A, 154 unexposed control cases; Group B, 21 exposed cases without VWF; Group C, 31 cases with a history of VWF but without any signs of VWF within the last year; and Group D, 83 cases with active VWF within the last year. FSBP% measurements were taken at room temperatures of 23 +/- 1 and 21 +/- 1 degrees C, using a strain-gauge Digimatic 2000 plethysmograph (Medimatic).

At a room temperature of 23 +/- 1 degrees C, there was a significant difference between Groups A and D, and B and D. At a room temperature of 21 +/- 1 degrees C, there was a significant difference between Groups A and C, A and D, and B and D. The values in Group D were the lowest at both room temperatures. Assuming a cut-off value of 75% at 23 +/- 1 degrees C, the sensitivity and specificity were 65.2 and 87.5%, respectively. Assuming the same cut-off value at 21 +/- 1 degrees C, the sensitivity and specificity were 73.9 and 82.5%, respectively. These values were not too high. Most of the subjects with WVF in this study were retired and had not used vibratory tools for many years. The situation of the subjects may affect the results of the FSBP test. Our data did not confirm a difference in diagnostic accuracy between room temperatures of 23 +/- 1 and 21 +/- 1 degrees C.

Our study showed that the sensitivity and specificity of the FSBP test with a cut-off value of 75% at 23 +/- 1 degrees C, were 65.2 and 87.5%, respectively, and at 21 +/- 1 degrees C, they were 73.9 and 82.5%, respectively.