Table 3.

Variation in individual post-void residual (PVR) volume readings over the course of the study, stratified by therapy cohort, alpha-blocker use, baseline PVR volume group, and radiation cohort.

Parameter	Group	Number of patients	Mean of N weeks of PVR readings	p-value	Mean Std. Dev. of N PVR readings	p-value
			Mean ± SD		Mean ± SD
Alpha-blocker use	No	29	26.5 ± 29.3	0.027	22.3 ± 18.8	0.011
	Yes	96	54.7 ± 65.6		35.7 ± 36.9
Baseline PVR volume	≤ 40 cc	76	23.2 ± 31.7	< 0.001	23.4 ± 32.7	<0.001
	> 40 cc	49	86.9 ± 72.7		46.7 ± 31.4
Radiation cohort	Prostate only	66	46.3 ± 55.4	0.725	29.7 ± 21.6	0.317
	Pelvis	59	50.2 ± 65.6		35.8 ± 43.9
Overall population		125	48.2 ± 60.2		32.5 ± 34.0

* The median number N of PVR readings was 10.

p-values were calculated by independent samples t-test.