Two machines, the Clinitek 200 and the Rapimat II/T, were evaluated for their ability to screen urine samples for significant bacteriuria and other elements indicative of urinary tract pathology. The automated screening procedures were compared with a conventional approach of microscopy and quantitative culture for 1020 urine specimens obtained from patients in a 700 bed general hospital. When compared with the bacterial culture method both machines gave identical results with a negative predictive value of 0-99, while when compared with microscopy alone the Clinitek 200 and Rapimat II/T gave negative predictive values of 0-92 and 0-87, respectively. It is concluded that both machines would provide cost effective screening of urine specimens. Department of Microbiology, University ofWestern Australia, Queen Elizabeth H Medical Centre, Nedlands 6009, Western Australia R A Bowman Sir Charles Gairdner Hospital, Queen Elizabeth II Medical Centre T V Riley Correspondence to: Mr R A Bowman Accepted for publication 16 August 1990 Investigation of urinary tract infection remains a major component of the workload in a clinical bacteriology laboratory. Increasing pressures for cost effective diagnostic procedures have precipitated the introduction of numerous screening systems for the early detection of bacteriuria or pyuria or both.' Of these screening methods, the use of multipatch strips has received much attention, particularly strips detecting leucocyte esterase and nitrite.2 Recent evaluations of this type of approach have produced a wide range of results.6 Several factors have probably contributed to this divergence of opinion including the definition of significant bacteriuria and pyuria, different microscopic and culture methods, and different patient populations. Subjective visual assessment of the strip reactions may also have been an important but less measurable factor. In an effort to reduce subjectivity and individual operator bias in reading test strips the use of automated reading machines has been suggested.67 We report here an evaluation of two of these machines, the Clinitek 200 (Ames Inc, Elkhart, Indiana, USA) and the Rapimat II/T (Behring, Marburg, Germany), as screening procedures for the detection of significant bacteriuria. The systems were also evaluated for their ability to screen urine samples for the presence of other elements indicative of urinary tract pathology.