The Effects of Proficiency and Bias on Residents’ Interpretation of the Microscopic Urinalysis

Objective . This study aims to determine whether residents are influenced by clinical information when interpreting microscopic urinalysis (UA) and estimating the probability of a urinary tract infection (UTI), and to determine the accuracy and reliability of UA readings. Design . Residents estimated the UA white blood cell count and the probability of a UTI in vignettes using a fractional factorial design, varying symptoms, gender, and the white blood cell count on preprepared urine slides. Results . Individual-level results indicated a clinical information bias and poor accuracy. Seventeen of 38 residents increased the white blood cell count in response to female gender; 14 increased the white blood cell count in response to UTI symptoms. Forty-nine percent of the readings were inaccurate; agreement ranged from 50% to 67% for white and red blood cells and bacteria. Conclusion . Many residents gave inaccurate UA readings, and many readings varied with clinical information. A significant portion of residents needs assistance in objectively and accurately interpreting the UA.