Findings:
(1) Uroflowmetry measures are dependent on the voided volume of urine.
(2) The flow variables decline with advancing age.
(3) The median urine volume voided was 208 mL with a third voiding less than 150 mL.
(4) Plotting variables vs the square root of the urine volume gave linear relations for urine volumes less than 450 mL.
Q max in mL/s
97.5%ile line:
Qmax in mL/s = (1.62 * (square root of urine volume in mL)) + 1.03
50%ile line:
Qmax in mL/s = (0.91152 * (square root of urine volume in mL)) - 0.01576
2.5%ile line:
Qmax in mL/s = (0.4788 * (square root of urine volume in mL)) + 0.0206
Q ave in mL/s
Qave = (voided volume in mL) / (flow time in seconds)
97.5%ile line:
Qave in mL/s = (0.946 * (square root of urine volume in mL)) + 0.1444
50%line:
Qave in mL/s = (0.447167 * (square root of urine volume in mL)) + 0.15333
2.5%line:
Qave in mL/s = (0.2033 * (square root of urine volume in mL)) + 0.002222
