Cross-cultural development of a quality of life measure for men with erection difficulties.
Erection difficulties have a profound effect on a man's quality of life, however, the emotional consequences are often overlooked in quantitative research where most sex-related questionnaires focus on a man's functional ability. Consequently, we developed a cross-cultural instrument to measure quality of life specific to male erection difficulties (QOL-MED). The items in the QOL-MED originated from interviewing forty men with erection difficulties In Seattle and Boston. Twelve men in the USA and 29 men in England helped us refine the instrument. Testing the QOL-MED's psychometric properties involved two administrations over a two-week period in the USA (n = 40) and the UK (n = 29). For discriminant validity, we predicted quality of life would worsen with increased self-perceived severity of the condition. After controlling for years with erection difficulties in a linear regression model, we found a significant negative association between self-perceived severity and quality of life for men in the UK only (p < 0.01). The expectation that the measure would produce evidence for convergent validity by being more closely correlated to well-being than functional status was not confirmed. Both the USA and UK instruments were internally consistent (Cronbach's alpha = 0.94 and 0.96, respectively), and reproducible (0.78 and 0.95, respectively). This instrument provides a promising tool for studying therapies and understanding quality of life in patients with erectile dysfunction.