Development of a nomogram for predicting a positive repeat prostate biopsy

Table 3 Multivariable logistic regression analysis in predicting positive repeat biopsy with generalized estimating equations adjustment for clustering repeat biopsies from the same patients

Predictor variables	Q1	Q3	Odds ratio	Lower 0.95	Upper 0.95	P
Age, yr	62	73	1.6	1.1	2.5	0.002
No. of previous biopsy sessions	1	2	2.3	0.8	6.2	0.002
No. of biopsy cores	10	12	1.6	1.3	2.1	0.001
Cumulative No. of cores	8	20	0.3	0.1	0.8	0.001
Months from the initial biopsy	10.3	36	0.6	0.2	2.0	0.727
Months from the previous biopsy	7.1	22.7	1.5	0.6	3.8	0.651
PSA slope (ng/mL per year)	-0.3	2.4	0.9	0.9	1.0	0.007
PSA (ng/mL)	6	11.4	1.0	0.3	4.0	0.098
Prostate volume (cc)	33.5	60.5	3.3	0.5	20.8	0.081
TZ prostate volume (cc)	15	36.1	0.1	0.0	1.0	0.116
PSA density (ng/mL per cc)	0.1	0.3	2.5	0.3	24.7	0.045
PSA TZ density (ng/mL per cc)	0.2	0.6	0.8	0.1	6.9	0.328
DRE-positive: negative	NA	NA	0.7	0.3	1.7	0.393
TRUS-positive: negative	NA	NA	1.4	0.8	2.6	0.218
HGPIN-positive: negative	NA	NA	2.2	0.9	5.2	0.080
ASAP-positive: negative	NA	NA	2.2	1.1	4.7	0.035

TRUS: Transrectal ultrasonography; HGPIN: High grade prostatic intraepithelial neoplasia; ASAP: Atypical small acinar proliferation; TZ: Transitional zone; PSA: Prostatic specific antigen; DRE: Digital rectal exam.