Purpose: Urinary tracts infections (UTI) are the most common cause of bacterial and hospital based infections. The gold standard in the diagnosis of UTI is urine culture. Patients with suspected UTI are usually requested for urinalysis simultaneously with urine culture. In general practice only 20-25 % of urine culture tests are found to be positive. In our study we assessed the need for urine culture requests by considering some urinalysis parameters on a software for iRICELL 2000 automated urine analyzer.

Material and Methods: We performed our study on 493 volunteers samples which were simultaneously requested for urinalysis together with urine culture. Samples are analyzed for both urinalysis and urine culture. The principal of the software we used was to consider the count of microscopic analyze parameters; leukocyte, bacteria, all small particles (ASP) and chemical analyze parameters; leukocyte esterase and nitrite positivity to alarm us for the further need of urine culture requests. The cut-offs of these parameters are as follows; leukocyte ≥ 5 /hpf, presence of bacteria, ASP ≥ 7000 /microliter, positivity of leukocyte esterase and nitrite. In addition to the parameters considered on this software we also assessed the protein, erytrocyte, epitelial cells which are known to be increased in UTI.

Results: We determined positive urine culture (culture (+)) results in 24.1 % of total sample. Leukocyte, ASP, eritrocyte values were statistically significant in culture (+) group comparing to culture (-) group (p=0.0001). Odds ratio values (95 % CI: Confidence Interval) for leukocyte esterase, nitrite (+), bacteria (+), leucocyte> 5 and ASP>7000 were found to be 5.63, 34.02, 8.18, 4.48, 2.17 respectively. In 91.6 % culture (+) group all 5 parameters examined were above the determined cut-offs and they were considered to be iRICELL (+). The probability of positive urine cultures in İRICELL (+) group was 6.52 times greater than İRICELL (-) group. Accepting the urine culture results as gold standard we found sensitivity 91.6 %, specifity 62 %, PPV 32 %, NPV 93 %, accuracy 50 % for iRICELL 2000 method.

Conclusion: When high sensitivity and negative predictive values of urinalysis are considered automated urinalysis can be used for negative screening by reducing the need for urine culture requests.