Invasive urodynamic studies for the management of lower urinary tract symptoms (LUTS) in men with voiding dysfunction

Background on the condition

Voiding symptoms - one specific group of lower urinary tract symptoms - are those experienced by men who have difficulty passing urine. Voiding symptoms may include a slow stream of urine, spraying of urine, difficulty in beginning urination and dribbling of urine once the man believes he has finished. These symptoms can be extremely embarrassing and distressing for affected individuals and may dictate or restrict how they live their lives.

Invasive urodynamic tests are used to measure nerve and muscle function, pressure around and in the bladder and other factors that might help to explain why a man may experience these symptoms. Some men find these tests embarrassing or uncomfortable. However, results might reveal the cause of the voiding symptoms, thereby guiding healthcare providers in choosing the most effective treatment. This approach might lead to improvement in the relative success of these treatments and reduce the risk of harm from unnecessary treatment.

Main findings of this review

We found two trials, which included around 350 men, although information was available for only 339 men in one trial. Evidence was not sufficient to show whether invasive urodynamic tests led to better patient outcomes. Some evidence suggests that these tests did alter management decisions, resulting in fewer men undergoing surgery. No evidence indicates whether this change in management led to fewer symptoms in men after treatment, and it is not known whether patients reported a better quality of life.

Adverse effects

No information obtained from the included trials reveals how common side effects were in those undergoing invasive urodynamic testing.

Limitations of the review

Not enough information from trials is available regarding the benefits of invasive urodynamic testing for men with voiding dysfunction. More research is needed in which people are randomly assigned to treatment decisions based on their symptoms, physical examination findings and results of non-invasive tests alone, or based on the extra information provided by invasive urodynamic tests. Future studies will help healthcare providers determine whether patients benefit from these extra tests, and whether the tests provide good value for healthcare systems.

Authors' conclusions: 

Although invasive urodynamic testing did change clinical decision making, we found no evidence to demonstrate whether this led to reduced symptoms of voiding dysfunction after treatment. Larger definitive trials of better quality are needed, in which men are randomly allocated to management based on invasive urodynamic findings or to management based on findings obtained by other diagnostic means. This research will show whether performance of invasive urodynamics results in reduced symptoms of voiding dysfunction after treatment.

Read the full abstract...

Invasive urodynamic tests are used to investigate men with lower urinary tract symptoms (LUTS) and voiding dysfunction to determine a definitive objective diagnosis. The aim is to help clinicians select the treatment that is most likely to be successful. These investigations are invasive and time-consuming.


To determine whether performing invasive urodynamic investigation, as opposed to other methods of diagnosis such as non-invasive urodynamics or clinical history and examination alone, reduces the number of men with continuing symptoms of voiding dysfunction. This goal will be achieved by critically appraising and summarising current evidence from randomised controlled trials related to clinical outcomes and cost-effectiveness. This review is not intended to consider whether urodynamic tests are reliable for making clinical diagnoses, nor whether one type of urodynamic test is better than another for this purpose.

The following comparisons were made.

• Urodynamics versus clinical management.

• One type of urodynamics versus another.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, issue 10), MEDLINE (1 January 1946 to Week 4 October 2014), MEDLINE In-Process and other non-indexed citations (covering 27 November 2014; all searched on 28 November 2014), EMBASE Classic and EMBASE (1 January 2010 to Week 47 2014, searched on 28 November 2014), and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) (searched on 1 December 2014 and 3 December 2014, respectively), as well as the reference lists of relevant articles.

Selection criteria: 

Randomised and quasi-randomised trials comparing clinical outcomes in men who were and were not investigated with the use of invasive urodynamics, or comparing one type of urodynamics against another, were included. Trials were excluded if they did not report clinical outcomes.

Data collection and analysis: 

Three review authors independently assessed trial quality and extracted data.

Main results: 

We included two trials, but data were available for only 339 men in one trial, of whom 188 underwent invasive urodynamic studies. We found evidence of risk of bias, such as lack of outcome information for 24 men in one arm of the trial.

Statistically significant evidence suggests that the tests did change clinical decision making. Men in the invasive urodynamics arm were more likely to have their management changed than men in the control arm (proportion with change in management 24/188 (13%) vs 0/151 (0%), risk ratio (RR) 39.41, 95% confidence interval (CI) 2.42 to 642.74). However, the quality of the evidence was low.

Low-quality evidence indicates that men in the invasive urodynamics group were less likely to undergo surgery as treatment for voiding LUTS (164/188 (87%) vs 151/151 (100%), RR 0.87, 95% CI 0.83 to 0.92).

Investigators observed no difference in urine flow rates before and after surgery for LUTS (mean percentage increase in urine flow rate, 140% in invasive urodynamic group vs 149% in immediate surgery group, P value = 0.13). Similarly, they found no differences between groups with regards to International Prostate Symptom Score (IPSS) (mean percentage decrease in IPSS score, 58% in invasive urodynamics group vs 59% in immediate surgery group, P value = 0.22).

No evidence was available to demonstrate whether differences in management equated to improved health outcomes, such as relief of symptoms of voiding dysfunction or improved quality of life.

No evidence from randomised trials revealed the adverse effects associated with invasive urodynamic studies.