SMOKING WITHDRAWAL PROGRAMME: BASELINE INDICATORS OF SMOKING EXPOSURE AND BIOCHEMICAL MONITORING OF SUCCESSFUL OUTCOME

Abstract

Sixty-four subjects who participated in a smoking withdrawal programme were analysed with respect to the relative usefulness of biochemical and hematological indices of smoking exposure. Plasma thiocyanate was found to be the best biochemical correlate of baseline cigarette consumption when compared to salivary thiocyanate or expired air carbon monoxide. Both plasma and salivary thiocyanate also correlated significantly with depth of inhalation per cigarette but not with any other questionnaire index of smoking exposure. After six weeks of successful smoking cessation all three indices fell significantly. Plasma thiocyanate proved the most sensitive biochemical index for monitoring ultimate outcome, accurately dichotomizing 90% of subjects as successful or unsuccessful in their attempts to stop smoking. The use of all three variables allowed accurate classification of 96% of subjects. White cell count, red cell count and hemoglobin also correlated significantly with baseline cigarette consumption and a significant decrease in these hematological indices occurred consequent to successful smoking cessation. However, these hematological changes were not as sensitive as biochemical indices in monitoring successful outcome.