305 alcohol offenders regranting their driving licence and undergoing MPA agreed to take part in a study where CDT and other newer markers (e.g. methanol, isopropanole) were evaluated in addition to routinely used alcohol markers like GGT, ASAT, ALAT and MCV. Methanol and isopropanole were elevated only in single cases. Highest prevalences were found for GGT (elevated in 26%) and - despite a prewarning time of appr. 4 weeks - for CDT (24%). No clear correlations between the markers were found. GGT and CDT coincided in only 6.9%, possible explanations are different drinking patterns, half times or biochemical properties like non responding. From 53 cases with exclusively elevated CDT only 4 had a negative medical assessment, whereas the psychologists rated 30 more of these as unfit to drive (MDs and psychologists were blinded for CDT values). From 59 with excl. elevated GGT 26 had a positive medical assessment resp. a non alcoholic reason as drugs etc. was assumed, without knowledge of (mostly normal) CDT. These and other results and aspects of the study underline that biochemical markers are an indispensable part in the assessment resp. procedure of regranting licenses. Methanol etc. should be used in suspicious cases, whereas CDT should be added to the routine protocol for a better and safer evaluation.
Samenvatting