Detection of relapses in alcohol dependent patients using serum carbohydrate deficient transferrin: improvement with individualized reference levels.

Alcohol dependent male outpatients were monitored for a period of six months. Indicators of alcohol consumption were compared using clinical information three times per week, serum levels of carbohydrate deficient transferrin (CDT) weekly and urine samples of 5-hydroxytryptophol daily. Individualized reference values of CDT were calculated by using an increase of three times the lowest coefficient of variation in the group, which meant that an increase of < or = 30% from the lowest value of each individual was considered a significant increase, and therefore an indication of alcohol consumption. By this approach, it was possible to improve the ability to detect relapses in alcohol dependent patients using serum CDT once a week compared to CDT using reference values recommended by the manufacturer.