Discrepancies Between Free and Invasive Uroflowmetry in Women Vary Among Different Clinical Contexts

Area of Science:

• Urology
• Gynecology
• Urogynecology

Background:

• Uroflowmetry is a key diagnostic tool in evaluating lower urinary tract symptoms.
• Discrepancies between free uroflowmetry (fQmax) and invasive uroflowmetry (iQmax) can impact clinical interpretation.
• Understanding these differences across various diagnoses is crucial for accurate patient management.

Purpose of the Study:

• To compare free and invasive uroflowmetry measurements in women.
• To analyze how discrepancies (ΔQmax) between fQmax and iQmax vary based on clinical diagnoses.
• To assess the influence of clinical context on uroflowmetry measurement differences.

Main Methods:

• Retrospective cross-sectional study of 407 women aged ≥18 years undergoing urodynamic studies (UDS).
• UDS included free uroflowmetry, cystometry, and pressure-flow studies.
• Patients were categorized into five clinical groups: voiding dysfunction (VD), mixed urinary incontinence (MUI), stress urinary incontinence (SUI), overactive bladder-urge incontinence (OAB), and prior anti-incontinence surgery.

Main Results:

• Median fQmax (30 ml/s) was significantly higher than iQmax (17 ml/s), with a median ΔQmax of 12 ml/s.
• Poor correlation (r = 0.271) was observed between fQmax and iQmax.
• ΔQmax was lowest in VD (5 ml/s) and highest in SUI (17 ml/s); patients with diabetes and urodynamic SUI showed lower and higher ΔQmax, respectively. Altered bladder sensation correlated with lower ΔQmax.

Conclusions:

• Significant variations in uroflowmetry measurement discrepancies exist across different clinical diagnoses in women.
• Stress urinary incontinence (SUI) exhibits the largest difference between free and invasive uroflowmetry.
• Voiding dysfunction (VD) and altered bladder sensation are associated with smaller discrepancies, emphasizing the need for context-specific interpretation of flow parameters.