title: Reproducibility of uroflow measurement: experience during a double-blind, placebo-controlled study of doxazosin in benign prostatic hyperplasia.
abstract: OBJECTIVE
  To evaluate the interindividual and intraindividual variation of uroflow measurements in men with benign prostatic hyperplasia (BPH).
  
  
  METHODS
  A total of 147 men with clinical evidence of BPH underwent two uroflow measurements at each of two screening visits prior to recruitment into a placebo-controlled study of doxazosin in the treatment of BPH. The maximum and mean flow rates were determined on each occasion. Differences in the mean value of both parameters for the cohort were examined. The intraindividual variability was evaluated using intraclass correlation coefficients and differences in maximum uroflow at each visit were examined.
  
  
  RESULTS
  Uroflow measurements for the cohort were reproducible and there was no clinically significant difference in maximum and mean flow rate on each occasion. However, the intraclass correlation coefficients for the mean and maximum flow rate varied between 0.70 and 0.82, indicating that intraindividual variation accounted for a substantial component of the total variation in uroflow observed among these patients. For many individuals, test-retest differences were clinically relevant.
  
  
  CONCLUSIONS
  For a group of patients, maximum and mean uroflow measurements are reproducible. However, for an individual, these parameters are subject to clinically significant variation and a single measurement may not be representative. This may be important when considering the need for therapeutic intervention.
authors.affiliation: Department of Urology, Royal Hospitals NHS Trust, St Bartholomew's Hospital, London, United Kingdom.
authors.forename: M R
authors.initials: MR
authors.lastname: Feneley
authors.forename: W D
authors.initials: WD
authors.lastname: Dunsmuir
authors.forename: J
authors.initials: J
authors.lastname: Pearce
authors.forename: R S
authors.initials: RS
authors.lastname: Kirby
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D018849:Controlled Clinical Trials as Topic; D004311:Double-Blind Method; D017292:Doxazosin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011470:Prostatic Hyperplasia / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D015203:Reproducibility of Results; D001748:Urinary Bladder Neck Obstruction / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D014563:Urodynamics
chemical_list: D000317:Adrenergic alpha-Antagonists; D017292:Doxazosin