Brazilian version of the King’s Health Questionnaire: assessment of the structural validity and internal consistency in female urinary incontinence

Abstract

Introduction and hypothesis The use of valid patient-reported outcome measurements is essential in clinical and research settings. The structure of the Brazilian version of the King’s Health Questionnaire (Br-KHQ) has not been evaluated. Thus, this study sought to evaluate the structural validity and internal consistency of the multi-item domains of the Br-KHQ in women with urinary incontinence (UI).

Methods A total of 462 Brazilian Portuguese speakers with UI aged 18 years or older were included in this study. Participants answered the Br-KHQ, and a questionnaire containing demographic and personal information. The structure of the Br-KHQ was examined through Exploratory Factor Analysis (EFA) with the implementation of parallel analysis and evaluated using confirmatory factor analysis (CFA). For the latter, several goodness-of-fit indices were considered to evaluate the model fit of the structures tested in this study. Internal consistency was assessed using Cronbach’s alpha, composite reliability, and coefficient omega.

Results The EFA showed that the questionnaire has a five-factor structure, i.e., limitations of daily life, personal relationship, emotions, sleep/energy, and severity measures. The CFA demonstrated that this structure presented the most adequate goodness-of-fit indices and the lowest values of Akaike information criterion and Bayesian information criterion, compared with the original and Portuguese structure. High values (>0.70) of internal consistency were found.

Conclusions The Brazilian version of the KHQ is composed of a five-factor structure. Further studies should evaluate other measurement properties of the Br-KHQ to ensure reliable interpretation of this patient-reported outcome measure in clinical practice.