Analysis of female voiding dysfunction: a prospective, multi-center study

Female voiding dysfunction lacks clear definitions or objective data even to this day due to the relatively low prevalence and complex etiologies of voiding dysfunction in women compared to men. The prevalence varies widely from 2.7 to 23 % (Nitti et al. in J Urol 161(5):1535–1540, 1999; Rees et al. in Br J Urol 47(7):853–860, 1975; Groutz et al. in Neurourol Urodyn 19(3):213–220, 2000; Farrar et al. in Br J Urol 47(7):815–822, 1975; Massey and Abrams in Br J Urol 61(1):36–39, 1988; Chassagne et al. in Urology 51(3):408–411, 1998). Diagnostic criteria and management of female voiding dysfunction have not yet been established. We performed a prospective, multi-center study at nine hospitals to investigate the characteristics and prevalence of female voiding dysfunction.

A total of 1,415 women visited urology clinics in nine hospitals from September to December 2005. Among them, 792 patients presented with lower urinary tract symptoms (LUTS). We analyzed their urinary symptoms with an International Prostate Symptom Score (IPSS) and obtained objective data using uroflowmetry, residual urine volume, and urinalysis. The authors hereby define female voiding dysfunction as maximum flow rate (Q _max) of 15 ml/s or less, which may be due to either bladder outlet obstruction (BOO) or bladder dysfunction caused by detrusor underactivity. BOO was defined as Q _max <15 ml/s with detrusor pressure >20 cmH₂O at Q _max, and detrusor underactivity was defined as Q _max <15 ml/s with detrusor pressure <20 cmH₂O at Q _max on pressure flow studies.

Hundred and two patients (12.8 %) from a total of 792 LUTS patients complained of voiding difficulty. Mean total IPSS score, mean IPSS subscores for voiding and storage symptom was 19.5 ± 7.9, 12.0 ± 5.0, and 8.4 ± 3.4, respectively. Among the seven categories of IPSS, incomplete emptying was the most common symptom followed by weak stream. Eighty-nine patients (87.2 %) from a total of 102 voiding dysfunction patients showed BOO, while 13 patients (12.8 %) showed detrusor underactivity. Concomitant diseases observed with voiding dysfunctions were overactive bladder (32 patients), stress urinary incontinence (25), detrusor underactivity (13), previous stress urinary incontinence surgery (12), pelvic organ prolapse (4), and anatomical obstruction (3 patients).

The prevalence of voiding difficulty in female urology patients who visit urologic office clinic was 7.2 and 12.8 % in female LUTS patients. Voiding symptoms were more common than storage symptoms, while functional BOO was more prevalent than detrusor underactivity in female voiding difficulty patients. We may expect alpha blockers to be an effective treatment option in female voiding difficulty due to functional BOO.