Reliability and Validity of the King's Health Questionnaire for Male Lower Urinary Tract Symptoms in Taiwan

Abstract

Objectives: The aim of this study is to evaluate the psychometric properties of the Iranian version of the Quality of Life (QoL) questionnaire in patients with urinary incontinence (UI). Methods: The English questionnaire on lower urinary tract symptoms was initially translated into Persian, and then back-translated into English. Final modifications were made after testing the questionnaire on Iranian patients with UI. To validate the translated questionnaire, the following tests were undertaken: content/face validity, internal consistency/reliability and construct validity. Results: The Lower Urinary Tract Symptoms Quality of Life (LUTS-QoL) questionnaire showed good internal consistency, content validity, and criterion validity, as measured by correlation with scores on the Short-Form 36 Health Survey (SF-36). Cronbach's alpha coefficient was 0.951, indicating a high internal consistency. Concerning criterion validity, correlations between the LUTS-QoL and subscales of the SF-36 were 0.563-0.193. The highest correlation was found between the LUTS-QoL and the social function subscale of the SF-36. Conclusion: The Iranian version of the LUTS-QoL questionnaire is a valid and robust instrument that can be used reliably in clinical settings and in research.

Validade e confiabilidade do King’s Health Questionnaire em homens submetidos à prostatectomia radical

“…The factor loadings ranged from 0.499 to 0.898 for Factor 1 and from 0.339 to 0.937 for Factor 2. Although the factor loading of the item related to the domain General health perception was below 0.40, we decided to keep it because the literature also reported values very close to those found here (Huang et al, 2014;Okamura et al, 2009).…”

“…Concerning the structural analysis of the instrument, it should be noted that the original author (Kelleher et al, 1997) did not present those results in his study. Two studies (Huang et al, 2014;Okamura et al, 2009) with women and men with urinary symptoms found a three-factor structure. Despite the divergence about the data in the literature, the two-factor structure found here showed satisfactory fit indices (Damásio, 2012), which supports the structural validity of the instrument in this population.…”

“…Concerning the correlations between the KHQ domains and the instruments used to assess UI severity (pad test and 24 h pad-count) that indicated worse QoL in individuals with severe UI, a study on the reliability and validity of the KHQ in Chinese men found that the KHQ scores among participants with severe and moderate urinary symptoms were statistically higher than those found in the group with mild urinary symptoms (p < 0.05; Huang et al, 2014).…”

“…The analysis of reliability by domains found that Cronbach's alpha values for the domains of Sleep/energy and Severity measures and the Urinary symptoms scale were below 0.7, ranging from 0.64 to 0.67. An international study with 393 men who had different lower urinary tract symptoms found a satisfactory internal consistency of the KHQ, with coefficients ranging from 0.75 to 0.94 (Huang et al, 2014). Although Cronbach's alpha coefficients were low in some domains, all items were kept because the alpha values for all domains, except for the domain Personal relationships, and the McDonald's omega were satisfactory.…”

“…The KHQ was originally built and validated in English in 1997 (Kelleher et al, 1997) to assess the impact of UI on women's QoL. Validation studies in the male population were conducted in the United States (Margolis et al, 2011) and Taiwan (Huang et al, 2014), showing adequate content and construct validity and acceptable reliability. In Brazil, the KHQ was validated in the female population and showed adequate reliability and validity (Tamanini et al, 2003).…”