Use of a prostate model to assist in training for digital rectal examination

Objectives. To assess the accuracy of prostate size estimation on digital r ectal examination (DRE) before and after training with a three-dimensional prostate model relative to prostate volume by transrectal ultrasound (TRUS) . Methods. A total of 100 subjects underwent DRE by one of four family physic ians (FP1, n = 34; FP2, n = 26; FP3, n = 22; and FP4, n = 18). One half wer e examined before any training on DRE prostate size examination and one hal f after the physicians were trained. Training involved teaching with a thre e-dimensional prostate model having posterior surface areas corresponding t o the average dimensions of six different prostate volumes. The FPs were in structed to estimate the prostate size on the DRE to the nearest 5 g. A sin gle urologist unaware of the DRE results performed TRUS on all patients to measure the prostate volume. Results. Before training, the DRE size estimates ranged from 10 to 100 g (m ean +/- SD 32.8 +/- 21.6), with a TRUS volume of 11 to 122 g (mean +/- SD 3 8.9 +/- 23.1). The correlation between the DRE and TRUS estimates was 0.25, suggesting low agreement (intraclass correlation coefficient (ICC) 0.35, 9 5% confidence interval 0.31, 0.38). After training, 50 different patients h ad DRE size estimates of 10 to 100 g (mean +/- SD 39.4 +/- 19.7) and TRUS v olume of 10 to 119 g (mean +/- SD 41.5 +/- 24.1). The correlation between t he techniques was higher in patients examined after training (r = 0.765), s uggesting much better agreement between the techniques (ICC 0.87; 95% confi dence interval 0.86, 0.88). Among the physicians, agreement between DRE and TRUS was higher after training (ICC 0.64 to 0.96) than before training (IC C 0.02 to 0.49). Conclusions. Although the subjects examined before and after training diffe red, the agreement between TRUS and DRE prostate size estimates by the FPs appeared to be stronger after training with a three-dimensional prostate mo del. This model may be a useful tool to assist in training FPs and medical students to measure prostate size on DRE. UROLOGY 55: 690-693, 2000. (C) 20 00, Elsevier Science Inc.