Aims of Study
Impaired bladder emptying is common in frail older adults. This study is designed to test the hypothesis that improvement in bladder emptying is associated with improving mobility in a rehabilitation ward for older adults.

Methods
Consecutive admissions to a rehabilitation ward for older adults were considered for inclusion in the study in the week after admission to the ward. Exclusion criteria were cognitive impairment such that consent could not be obtained, non-English speaking, or presence of an indwelling urinary catheter. A post-void residual (PVR) bladder volume and Rivermead Mobility Index (RMI) were completed for subjects who gave consent, on a weekly basis until discharge. The BladderScan BVI 3000, Diagnostic Ultrasound, instrument was used. Statistical analysis was by a general linear model for correlated data.

Results
In the study period 114 people were admitted and 57 approached for consent. 24 people gave consent. One person was found to be in urinary retention, with a PVR of greater than 700 ml. After excluding this subject the square root of the PVR and RMI were positively correlated with a coefficient of 0.31. This value was not significantly different from zero but there was a very high power to exclude a clinically significant decline in PVR with improving mobility. 50% of participants had at least one PVR greater than 100 ml.

Conclusions
This study suggests that PVR does not decline with improvement in mobility in older adults receiving inpatient rehabilitation. There is a high prevalence of elevated PVR in this frail group of older adults.