Improving Diagnosis: A study of Siemens Clinitek Status+ verses the ARKRAY AUTION MAX AX-4030 Analyzer for Suspected Urinary Tract Infections

Background
The purpose of the study is to evaluate the performance of the urinalysis (UA) screening analyzers. Rapid point-of-care (POCT) urine dipstick testing in the emergency department (ED) was compared to a laboratory automated platform.

Methods
A total of 30 urine specimens were collected from the emergency department at our hospital and were simultaneously tested for urinalysis (UA) on POCT Siemens Clinitek Status+ analyzer using the Multistix 10SG strip. In the laboratory we performed the tests on the automated ARKRAY Aution MAXTM instrument, using the Aution Sticks 9EB strips. Samples with more than a trace of leukocyte esterase and/or nitrates are considered positive for a urinalysis and further, the samples were reflexed to urine culture. The performance of both platforms was analyzed using EP Evaluator (Data Innovations LLC.).

Results
A total of 30 urine specimens were analyzed for UA using both the POCT and automated laboratory analyzers. The agreement (95% CI) between leukocyte esterase, nitrites, and blood are as follows: 53.3% (36.1 to 69.8%); 96.7% (83.3 to 99.4%), and 70.0% (52.1 to 83.3%) (see Table 1.). Furthermore, out of the 30 specimens that were tested on both platforms, there was prominent discordance between the POCT and lab UA test. The 7 urine samples that were negative on POCT were positive on the laboratory UA platform. All 7 were sent for urine culture, out of 7 only 1 sample was positive for culture which was abnormal: >100,000 CFU/ml Escherichia coli. Out of 30 specimens that were tested on both platforms, 23 were in concordance with both the platforms out of which 8 patients tested positive for culture (5 were E. coli, 1 was E. coli combined with Klebsiella pneumoniae, 1 was solely Klebsiella pneumoniae, 1 was Staphylococcus saprophyticus, and 1 was Streptococcus agalactiae). The remaining 15 patients resulted for no significant growth of bacteria or suggesting contamination. The sensitivity of POCT UA and laboratory-performed UA was 89% and 100% respectively. Furthermore, the specificity of POCT UA and laboratory-performed UA was 36% and 7% respectively. 

Conclusion
Our data shows although POCT UA is rapid, a prominent disparity is observed between the POCT UA and automated lab testing. The lab-performed UA has greater sensitivity and specificity compared to the POCT UA. Clinicians should interpret the urine dipstick test results in a clinical context that includes the patient’s history and symptoms, especially when using POCT in the ED. 

Learning Objectives:

• Comparing the performance of  the two urinalysis platforms

• Identifying the gaps between the two platforms

• Recommend education on disconnect between patient’s symptoms vs test results.