Interobserver variation of prostatic volume estimation with digital rectal examination by urological staffs with different experiences

Abstract

Purpose: To compare the accuracy of estimating prostatic volume with digital rectal examination (DRE) by urological staffs with different experiences. Measurement of prostatic volume with transrectal ultrasonography (TRUS) serves as the reference standard.

Materials and methods: Thirty-nine consecutive male patients admitted with acute urinary retention had their prostatic volume estimated with DRE by a urology junior trainee, a urology higher trainee and a trained urologist. All patients had TRUS to measure their prostatic volumes. Pearson correlation coefficients (r) were used to assess the relationships between the prostatic volume measured with TRUS and that estimated with DRE by the 3 urological staffs. Wilcoxon signed ranks tests were used to compare the discrepancies between the prostatic volume measured with TRUS and that estimated with DRE for the 3 Urological staffs, and to assess the inter-observer differences of these discrepancies.

Results: The correlation coefficients for the 3 urological staffs were r = 0.573 for the urology junior trainee, r = 0.541 for the urology higher trainee, and r = 0.640 for the trained urologist. The median discrepancies between the prostatic volume measured with TRUS and that estimated with DRE were -9.1 mL for the urology junior trainee, -1.3 mL for the urology higher trainee and 0.9 mL for the trained urologist. These discrepancies were statistically significant only in the case of urology junior trainee (p = 0.015, Wilcoxon signed ranks test). The difference in these discrepancies was statistically significant only between the urology junior trainee and the trained urologist (p = 0.003, Wilcoxon signed ranks test).

Conclusions: The trained urologist was more accurate in estimating prostatic volume with DRE than the urology junior trainee.