Reliability and Validity of the Quality of Life Questionnaire in Iranian Patients with Lower Urinary Tract Symptoms

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.