Researchers have found that the absence or presence of microhematuria does not accurately predict whether a distal ureteral stone is still present or has passed, according to a report in the Journal of Endourology (2008;22:1233-1236).
Gerald Yoon, MD, and his colleagues at Kaiser Permanente, Los Angeles Medical Center, studied 18 patients (average age 43.5 years) with an average distal stone size of 4.1 mm. The absence or presence of microhematuria was compared with results of repeated unenhanced helical CT of the abdomen and pelvis.
The sensitivity and specificity of urinalysis were 40% and 63%, respectively. The predictive value of a positive urinalysis was 57% and the predictive value of a negative test was 55%. The researchers concluded that “urinalysis is no better than randomness in predicting presence or absence of a stone by CT.”