LAUSR

period where the new machine was in use but traditional standards were being used to recommend evaluation) was performed. Descriptive statistics and analysis of variance (ANOVA) were performed to evaluate the findings. RESULTS: 405 urine samples were evaluated with the finding of 32.8% of the samples falling outside of the reference range of 0-3 HPF. This resulted in unevenly distributed data. A 95% confidence interval was then used to delineate a value. This produced a reference interval of 0-8 HPF. 229 patients underwent evaluation of microscopic hematuria during the time period. 72% of those had a completely negative work-up. 8 of 229 had cystoscopy or CT findings consistent with a malignancy. Only one of those patients was between the traditional threshold and our new limit for evaluation. Evaluation with linear regression did not demonstrate any statistical difference between the thresholds of 3 RBCs vs 8 RBCs (p[ 0.0524). CONCLUSIONS: The current guidelines for evaluation of microscopic hematuria may no longer be relevant with the use of new technology. Identifying a new reference range based on the machine is accurate and safe with regards to evaluations of hematuria.