[Evaluation of smoke consumption by the determination of serum thiocyanate (author's transl)].

The method of Butts and Coll. for determination of serum thiocyanate--parameter correlated to smoke assumption--has been modified in order to improve sensibility and has been characterized as regards precision and accuracy. The improved method has been successively utilized for determination of serum thiocyanate of 493 subjects during a screening for prevention from coronary heart disease. A linear correlation (r = 0,916) between the number of smoked cigarettes and serum thiocyanate has been found. Assuming 40 mumol/l as a cut-off point to distinguish cigarette smokers and non smokers, 1,8% false positive and 5% false negative resulted.