Validation of Portuguese version of Quality of Erection Questionnaire (QEQ) and comparison to International Index of Erectile Function (IIEF) and RAND 36-Item Health Survey

• Published in: International Brazilian Journal of Urology Vol. 41; no. 1; pp. 155 - 167
• Main Authors: Reis, Ana Luiza, Reis, Leonardo Oliveira, Saade, Ricardo Destro, Santos, Jr, Carlos Alberto, Lima, Marcelo Lopes de, Fregonesi, Adriano
• Format: Journal Article
• Language: English
• Published: Brazil Sociedade Brasileira de Urologia 01.01.2015
• Subjects: Adult; Aged; Aged, 80 and over; Brazil; Cross-cultural adaptation; Cross-Cultural Comparison; Erectile Dysfunction; Erectile Dysfunction - diagnosis; Humans; Language; Male; Middle Aged; Original; Penile Erection; Personal Satisfaction; Psychometrics - methods; Quality of Erection Questionnaire; Quality of Life; Reproducibility of Results; Severity of Illness Index; Statistics, Nonparametric; Surveys and Questionnaires - standards; Translations; Young Adult; Brazil
• ISSN: 1677-5538; 1677-6119; 1677-6119; 1677-5538
• DOI: 10.1590/S1677-5538.IBJU.2015.01.21

To validate the Quality of Erection Questionnaire (QEQ) considering Brazilian social-cultural aspects. To determine equivalence between the Portuguese and the English QEQ versions, the Portuguese version was back-translated by two professors who are native English speakers. After language equivalence had been determined, urologists considered the QEQ Portuguese version suitable. Men with self-reported erectile dysfunction (ED) and infertile men who had a stable sexual relationship for at least 6 months were invited to answer the QEQ, the International Index of Erectile Function (IIEF) and the RAND 36-Item Health Survey (RAND-36). The questionnaires were presented together and answered without help in a private room. Internal consistency (Cronbach's α), test-retest reliability (Spearman), convergent validity (Spearman correlation) coefficients and known-groups validity (the ability of the QEQ Portuguese version to differentiate erectile dysfunction severity groups) were assessed. We recruited 197 men (167 ED patients and 30 non-ED patients), mean age of 53.3 and median of 55.5 years (23-82 years). The Portuguese version of the QEQ had high internal consistency (Cronbach α=0.93), high stability between test and retest (ICC 0.83, with IC 95%: 0.76-0.88, p<0.001) and Spearman correlation coefficient r=0.82 (p<0.001), which demonstrated the high correlation between the QEQ and IIEF results. The correlations between the QEQ and RAND-36 were significantly low in ED (r=0.20, p=0.01) and non-ED patients (r=0.37, p=0.04). The QEQ Portuguese version presented good psychometric properties and high convergent validity in relation to IIEF. The low correlations between the QEQ and the RAND-36, as well as between the IIEF and the RAND-36 indicated IIEF and QEQ specificity, which may have resulted from the patients' psychological adaptations that minimized the impact of ED on Quality of Life (QoL) and reestablished the well-being feeling.