The ICIQ-FLUTS questionnaire is a validated tool to evaluate female lower urinary tract symptoms (LUTS) and impact on quality of life and has been validated for several languages. This fact facilitates comparisons between populations and enhances the generalizability of research findings which can have significant implications for healthcare practices, and research. The aim of this study was to translate and validate the ICIQ-FLUTS questionnaire into European Portuguese language.

Authorisation for adaptation and validation of the ICIQ-FLUTS was obtained from the ICIQ Advisory Board. The process of translation, cultural adaptation, and validation analysis was performed according to the ICIQ methodology. Translation and back translation procedures were conducted by bilingual translators, with the initial draft approved by the ICIQ Advisory Board. Content and face validity were assessed by a panel of clinical experts in LUTS and by women who completed the questionnaire. After revisions for wording, the final draft underwent pilot testing with a group of 10 women, requiring no further changes.

Women from the general population and from the urogynaecology outpatient clinic of a central hospital were invited to participate. The questionnaire was administered twice, approximately 7 days apart, to assess internal consistency (reliability) and stability (test-retest reliability) of the final version.

Statistical analysis
Normal distribution of variables was tested using the Kolmogorov-Smirnov test. Categorical variables are presented as n (%) and continuous variables as mean and standard deviation (SD) or median and interquartile range (IQR). Internal consistency was assessed using Cronbach’s alpha, while test-retest reliability was evaluated using Spearman’s correlation test and the Wilcoxon test for differences between two medians.

Of 135 women invited to participate, 20 did not return the second questionnaire. Nine questionnaires with missing data were excluded, resulting in 106 included participants. The participants, aged between 18 and 82 years (mean age: 44, SD: 13.5), had a median body mass index of 23.9 kg/m² (IQR: 5.5). The majority were married (64.2%), with varying levels of education, from no formal education to PhD. Over half reported symptoms of urinary incontinence (63.2%), with stress urinary incontinence, urgency urinary incontinence, and mixed urinary incontinence reported by 19.8%, 10.4%, and 33.0% of women, respectively.

For internal consistency, Cronbach’s alpha values were 0.835 and 0.877 for items a) and b), respectively. Results analysis regarding the influence of each item on internal consistency revealed only discreet variations in both a) and b) items in comparison with global Cronbach’s alpha (Table 1). 

Test-retest analysis showed no significant differences in scores for filling, voiding, and incontinence domains of the ICIQ-FLUTS (p > 0.05). Obtained values were (median (IQR) Test |Retest, p-value): Filling symptoms Score Items a) 2-5), (2(3) | 2(2), 0.974; Voiding symptoms Score Items a) 6-8 1(3) | 1(2), 0.130 and Incontinence symptoms Score Items a) 9-13 1(4) | 1(4), 0.616.

Spearman correlation coefficients ranged from 0.570 to 0.914. Lower values were obtained in voiding domain, in both a) and b) items (Table 2).

Of 135 women invited to participate, 20 did not return the second questionnaire. Nine questionnaires with missing data were excluded, resulting in 106 included participants. The participants, aged between 18 and 82 years (mean age: 44, SD: 13.5), had a median body mass index of 23.9 kg/m² (IQR: 5.5). The majority were married (64.2%), with varying levels of education, from no formal education to PhD. Over half reported symptoms of urinary incontinence (63.2%), with stress urinary incontinence, urgency urinary incontinence, and mixed urinary incontinence reported by 19.8%, 10.4%, and 33.0% of women, respectively.

For internal consistency, Cronbach’s alpha values were 0.835 and 0.877 for items a) and b), respectively. Results analysis regarding the influence of each item on internal consistency revealed only discreet variations in both a) and b) items in comparison with global Cronbach’s alpha (Table 1). 

Test-retest analysis showed no significant differences in scores for filling, voiding, and incontinence domains of the ICIQ-FLUTS (p > 0.05). Obtained values were (median (IQR) Test |Retest, p-value): Filling symptoms Score Items a) 2-5), (2(3) | 2(2), 0.974; Voiding symptoms Score Items a) 6-8 1(3) | 1(2), 0.130 and Incontinence symptoms Score Items a) 9-13 1(4) | 1(4), 0.616.

Spearman correlation coefficients ranged from 0.570 to 0.914. Lower values were obtained in voiding domain, in both a) and b) items (Table 2).

The Portuguese version of ICIQ-FLUTS has proven to be a valid and reliable tool for evaluating lower urinary tract symptoms in Portuguese women. Its importance lies in facilitating accurate assessment in both clinical and research settings, enabling healthcare providers to make informed decisions and tailor interventions accordingly. Furthermore, its implementation will contribute to the scientific foundation of healthcare research, fostering advancements in understanding and management of lower urinary tract symptoms in women.