PMID- 8705213
OWN - NLM
STAT- MEDLINE
DCOM- 19960911
LR  - 20220311
IS  - 0007-1331 (Print)
IS  - 0007-1331 (Linking)
VI  - 77
IP  - 6
DP  - 1996 Jun
TI  - The value of multiple free-flow studies in men with lower urinary tract symptoms.
PG  - 813-8
AB  - OBJECTIVE: To assess the variability of free-flow studies in men presenting with 
      lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction 
      (BPO) and to determine the sensitivity, specificity and predictive values of 
      consecutive measurements of maximum flow rate for the presence of bladder outlet 
      obstruction (BOO) at several threshold values. PATIENTS AND METHODS: The value of 
      multiple free-flow studies was assessed in 165 men presenting with LUTS 
      suggestive of BPO. Each patient was requested to void four times into a 
      uroflowmeter and the voided volume and post-void residual urine volume (PVR) were 
      also measured. The variability of the maximum flow rate (Qmax), voided volume and 
      PVR between consecutive voids was assessed. In addition, the sensitivity, 
      specificity, positive predictive value (PPV) and negative predictive value (NPV) 
      of various thresholds of Qmax for the presence of BOO were calculated for each 
      consecutive void. RESULTS: The mean Qmax on void 1 was 10.2 mL/s and the mean 
      maximum value for Qmax between voids 1 and 2 was 12.5 mL/s. For voids 1, 2 and 3, 
      the mean maximum Qmax was 13.9 mL/s and for voids 1 to 4 it was 15.2 mL/s. There 
      were no significant changes in PVR among any of these voids. There was a 
      statistically significant, although small, decrease in voided volume between 
      voids 1 to 3 and voids 1 to 4. The specificity and PPV of Qmax for BOO increased 
      with each subsequent void, such that using a threshold value for Qmax of 10 mL/s 
      on the fourth void, the specificity and PPV for BOO were 96% and 93%, 
      respectively. CONCLUSIONS: There was a significant increase in Qmax with each 
      successive void when men with LUTS suggestive of BPO performed multiple free-flow 
      measurements and consequently, single free-flow measurements substantially 
      underestimated the maximum Qmax that these patients achieved. The specificity and 
      PPV of Qmax for BOO can be improved considerably by performing multiple free-flow 
      studies and by carefully selecting an appropriate threshold value (although 
      whether pressure-flow studies are unnecessary will depend on what level of 
      specificity and PPV is deemed acceptable in clinical practice). These findings 
      should be considered if free-flow studies are to be used as the basis for 
      deciding the clinical management of men with LUTS and may be particularly useful 
      for urologists with limited facilities for pressure-flow studies.
FAU - Reynard, J M
AU  - Reynard JM
AD  - Bristol Urological Institute, Southunead Hospital, UK.
FAU - Peters, T J
AU  - Peters TJ
FAU - Lim, C
AU  - Lim C
FAU - Abrams, P
AU  - Abrams P
LA  - eng
PT  - Journal Article
PL  - England
TA  - Br J Urol
JT  - British journal of urology
JID - 15740090R
SB  - IM
MH  - Aged
MH  - Aged, 80 and over
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Predictive Value of Tests
MH  - Pressure
MH  - Prostatic Hyperplasia/complications/*physiopathology
MH  - Sensitivity and Specificity
MH  - Urinary Retention/etiology/*physiopathology
MH  - Urination/*physiology
MH  - Urodynamics
EDAT- 1996/06/01 00:00
MHDA- 1996/06/01 00:01
CRDT- 1996/06/01 00:00
PHST- 1996/06/01 00:00 [pubmed]
PHST- 1996/06/01 00:01 [medline]
PHST- 1996/06/01 00:00 [entrez]
AID - 10.1046/j.1464-410x.1996.00097.x [doi]
PST - ppublish
SO  - Br J Urol. 1996 Jun;77(6):813-8. doi: 10.1046/j.1464-410x.1996.00097.x.