Performance evaluation of Wisconsin laboratories performing implied consent alcohol determinations

Hospital, clinic, and public health laboratories are licensed to perform implied consent blood and urine alcohol determination. Methods include enzymatic, gas chromatographic, and distillation. The techniques of evaluation/certification are outlined. The performance exhibited no consistent bias toward high or low values. The distribution of participants' values, i.e. precision, indicated a 3% coefficient of variation performance. Laboratories showed an increase in quality of performance with time, especially after the initial 6 month period. Quality of results varied in the order: gas chromatographic, enzymatic, and distillation methods.