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.
OBJECTIVE
To validate the Quality of Erection Questionnaire (QEQ) considering Brazilian social-cultural aspects.


METHODS
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.


RESULTS
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).


CONCLUSIONS
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.
Department of Surgery (Urology), Faculty of Medical Sciences, University of Campinas (Unicamp), Brazil.
Ana Luiza
AL
Reis
Department of Surgery (Urology), Faculty of Medical Sciences, University of Campinas (Unicamp), Brazil.|Medicine (Urology), Center for Life Sciences, Pontifical Catholic University of Campinas (PUCCampinas), Brazil.
Leonardo Oliveira
LO
Reis
Department of Surgery (Urology), Faculty of Medical Sciences, University of Campinas (Unicamp), Brazil.
Ricardo Destro
RD
Saade
Department of Surgery (Urology), Faculty of Medical Sciences, University of Campinas (Unicamp), Brazil.
Carlos Alberto
CA
Santos
Department of Surgery (Urology), Faculty of Medical Sciences, University of Campinas (Unicamp), Brazil.
Marcelo Lopes de
ML
Lima
Department of Surgery (Urology), Faculty of Medical Sciences, University of Campinas (Unicamp), Brazil.
Adriano
A
Fregonesi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil; D003431:Cross-Cultural Comparison; D007172:Erectile Dysfunction / Q000175:diagnosis*; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D010410:Penile Erection; D010549:Personal Satisfaction; D011594:Psychometrics / Q000379:methods; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires / Q000592:standards*; D014177:Translations; D055815:Young Adult