Uroflowmetry in healthy women: Development and validation of flow-volume and corrected flow-age nomograms

Voiding dysfunction is common among women. However, unlike men, no universally accepted nomogram is available for them. This study was undertaken to establish normal reference values of urinary flow parameters for healthy Indian female population in menstrual age group.

Women volunteers of menstrual age group, including hospital staff, nursing students, visitors and relatives of patients, underwent free uroflowmetry using digital uroflowmeter (Solar Silver, Medical Measurement System, The Netherlands). Women with voiding symptoms, urinary tract infection within last 4 weeks, neurological/non-neurological diseases or medication affecting voiding function and abnormal uroflows were excluded. One micturition was obtained per proband in a sitting position to determine various uroflow variables.

Of total 343 women enrolled in the study, data of 308 was available for final analysis. Their mean (+/-SD) age was 33 +/- 8.63 years, voided volume 289.79 +/- 166.52 ml, maximum flow-rate (Q(max)) 23.06 +/- 9.40 ml/sec, average flow-rate (Q(ave)) 13.08 +/- 6.00 ml/sec, voiding time 23.50 +/- 12.52 sec, time to Q(max) 8.56 +/- 6.55 sec, and post-void residue 2.92 +/- 3.69 ml. Corrected Q(max) and corrected Q(ave) were computed to be 1.41 +/- 0.43 and 0.80 +/- 0.27, respectively. Confidence limit flow-volume nomograms were developed and validated using data of asymptomatic (n = 25) as well as symptomatic women (n = 22). Corrected Q(max) and corrected Q(ave) to age nomograms were also introduced.

These nomograms would help clinicians evaluate flow rates over a wide-range of voided volume as well as age, enabling effective screening of women for voiding dysfunction, and evaluating response to medical or surgical treatment.