Evaluation of six screening items for the vibration syndrome.

Six primary screening test items (grip strength, skin temperature, Nail-Press test, pain sense, and vibration sense at 125Hz and at 250Hz) for the vibration syndrome were assessed for validity and reliability using four measures: correlation with working time in years with vibrating tools; degree of relationship with four major complaints (Reynaud's phenomenon, numbness, coldness, and pain); correlation between two repeated examinations; values of t-test calculated on two groups of workers of comparable age, one having all of the four major complaints and the other having no complaint at all. Both left and right hand scores were used in the analysis with a total of 12 items. As these scores were too heterogeneous to make direct comparison, the screening items were ranked according to the values of the four measures and then the obtained ranks were totalled for each item to establish a further ranking. In this way, the ranks of each screening item were determined. The results indicated that: 1) For validity, pain sense and 250Hz vibration sense were found to have relatively high validity, followed by 125Hz vibration sense and grip force. Skin temperature and the Nail-Press test occupied the lowest ranks. 2) For reliability, grip force and 250Hz vibra tion sense were highest followed by pain sense. In this case again, skin temperature and the Nail Press test turned out to belong to the lowest group, which included the 125 Hz vibration sense. 3) The right and left hand scores were separately analyzed and the right hand scores tended to surpass the left hand ones, although these comparison were not statistically significant (in 8 out of 12 comparisons, right hand scores were superior to left hand ones for validity, and for reliability it was the case for 9 out of 12 cases). These results suggest that the two measures of the peripheral blood flow (i.e., skin temperature and the Nail-Press test) should be replaced by more reliable measures.