Validity and Reliability of the Thai version of the International Consultation on Incontinence Questionnaire – Female Lower Urinary Tract Symptoms Long Form (ICIQ-FLUTS LF) and Its Correlation with the IPSS

Abstract

Objective: Incontinence Modular Questionnaire on Female Lower Urinary Tract Symptoms Long form (ICIQ-FLUTS LF) is a robust psychometric tool to assess the severity of lower urinary tract symptoms (LUTS) in women. A Thai language version of the ICIQ-FLUTS LF is available, but it had not been validated yet. This study aimed to validate the ICIQ-FLUTS LF questionnaire in Thai and to identify the correlation between the ICIQ-FLUTS LF and the IPSS. Materials and Methods: We recruited 130 females, 50 with LUTS were recruited from patients visiting the Urology Clinic to assess the test with known group validity. They completed the ICIQ-FLUTS LF twice, two weeks apart, and the IPSS once. Meanwhile, 80 without LUTS (control group) were recruited from relatives of the patients to increase the consistency of the statistical analysis, completed the ICIQ-FLUTS LF. Then validity and reliability were determined using statistical analysis. Results: Convergent validity showed a moderate correlation between ICIQ-FLUTS LF and IPSS for both storage and voiding symptoms, with Pearson’s correlation coefficient 0.49, 0.66; P<0.001, respectively. Construct validity, using the Wilcoxon signed-rank test, demonstrated statistically significant difference between the target group and the control group (P<0.001). The Thai version of the ICIQ-FLUTS LF showed good internal consistency, with Cronbach’s alpha coefficients 0.76-0.79 and Test–retest reliability strong, with weighted kappa values 0.63 to 0.90. Conclusion: The Thai version of the ICIQ-FLUTS LF shows good validity and reliable measures of females with LUTS, and is simple to use. This questionnaire in the Thai version can be used in clinical practice and academic research.