Urine microscopy, an ill defined method, examined by a multifactorial technique

Abstract

The precision of routine urine microscopy for counting erythrocytes and leukocytes was evaluated by using a statistical research planning technique, factorial experimental design. The relative contribution of the technician preparing the urine specimen, the technician reading the urine slide, the time elapsed since receipt of the urine specimen, and the effect of the microscope used, are examined. Results obtained by various technicians differed significantly, because of variation in preparation techniques. It is demonstrated that the routine examination of urine for cellular components may be more imprecise than generally believed, and that the technique should be better defined. It is emphasized that the technique of factorial experiments can be used as an important tool for the design of a rational quality control program.