Lower urinary tract symptoms (LUTS), although central to clinical assessment, are often poor indicators of underlying lower urinary tract dysfunction. Invasive urodynamic studies (UDS) remain the gold standard for objectively evaluating lower urinary tract function. Discrepancies between patient-reported symptoms and urodynamic findings are common. This study assessed the correlation between symptoms, standardized questionnaire scores, and invasive urodynamic findings in patients undergoing UDS for LUTS.

This retrospective cross-sectional study included 302 patients (228 women, 74 men) with non-neurogenic lower urinary tract dysfunction who underwent videourodynamic studies at a single tertiary center. All underwent detailed history, physical examination, and symptom assessment using the ICIQ-FLUTS (women) or ICIQ-MLUTS (men). ICIQ-FLUTS domains were defined as storage (Q2–Q5), voiding (Q6–Q8), and incontinence (Q9–Q13). ICIQ-MLUTS domains were defined as storage (Q7, Q13, Q14), voiding (Q2–Q6), and incontinence (Q8–Q12). Domain total scores were calculated by summing individual item scores, and composite scores were derived as frequency × bother. Storage and incontinence domains were tested against DOA, urodynamic incontinence (INC), stress urinary incontinence (SUI), and DOA-related incontinence, whereas the voiding domain was tested against DUA and BOO. All studies were performed according to ICS standards and included video-assisted cystometry and pressure-flow studies. Correlations between symptom types, questionnaire scores, and urodynamic diagnoses were analyzed using Mann–Whitney U tests; p<0.05 was considered significant.

Mean age was 52.6±17.7 years. DOA was present in 46.4%, urodynamic incontinence in 50.0%, DUA in 23.2% of women and 35.1% of men. Domain-level results are summarized in Table 1. In women, the FLUTS storage domain was significantly associated only with DOA (p=0.029). The incontinence domain showed highly significant associations with INC, UUI, and SUI (all p<0.001) and DOA (p=0.029). The voiding domain was most strongly associated with DUA (53.6±39.5 vs 31.0±30.4, p=0.002) and also with BOO (51.4±33.8 vs 34.4±33.5, p=0.048). In men, no MLUTS domain significantly discriminated DUA (p=0.172) or BOO (p=0.710). The incontinence domain was significantly associated only with UUI (p=0.040). Women demonstrated stronger symptom score–urodynamic correlations than men. Key findings regarding the correlation of individual items with UDS are presented in Table 2. In women, FLUTS Q11 predicted SUI (p<0.001), and Q9 and Q3 distinguished both DOA and UUI. Among voiding questions, Q6 (hesitancy) showed the strongest association with DUA (p<0.001), while Q7 (straining) predicted both DUA (p=0.002) and BOO (p=0.004). In men, MLUTS Q7 and Q8 identified UUI (p=0.017, p=0.014), but Q10 failed to predict SUI (p=0.368). No MLUTS voiding question significantly predicted DUA or BOO. Bother alone failed for the incontinence domain vs DOA (p=0.082), while the composite rescued this (p=0.029). For corresponding items, correlations were consistently stronger in women than in men.

Each ICIQ domain showed a distinct pattern of urodynamic associations. The incontinence domain was the strongest discriminator overall. The voiding domain captured both DUA (p=0.002) and BOO (p=0.048) in women, with DUA showing the stronger association. This is clinically meaningful because DUA is difficult to diagnose without invasive pressure-flow studies, and elevated FLUTS voiding scores may serve as a screening signal. The stronger questionnaire–urodynamic correlations in women suggest that female patients describe their symptoms with greater discriminative accuracy through the ICIQ scoring system, possibly reflecting heightened awareness of specific symptom triggers in daily life.

ICIQ domain scores show domain-specific associations with videourodynamic diagnoses. The incontinence domain is most informative for filling-phase diagnoses, while the voiding domain captures both DUA and BOO in women. Women report symptoms more accurately than men. The consistent failure of analogous MLUTS questions to predict voiding dysfunction in men highlights a sex-based difference in symptom reporting that clinicians should consider when interpreting questionnaire results. These domain-level patterns may help guide ICIQ interpretation before urodynamic testing.