The predictive usefulness of age and kind of onset in discriminating psychogenic from organic impotence

It is well known in clinical practice that psychogenic impotence affects younger patients than organic impotence and with a more acute onset. In the present study the authors evaluated the predictive usefulness and discriminating power of the following sociodemographic and clinical variables: age, kind of onset (acute or gradual), civil status, number of partners, duration of illness. The sample was made of 133 patients suffering from erectile dysfunction for at least three months, consecutively admitted to the Multidisciplinary Centre for the Diagnosis and Treatment of Impotence of the Scientific Institute San Raffaele of Milan from May 1992 to April 1993. All patients underwent a thorough clinical and laboratory evaluation: 72 (54.5%) were psychogenic (mean age 42.6±11.2); 60 (45.5%) organic (mean age 56.3±9.8). Stepwise logistic regression model identified age and kind of onset as significant predictors of kind of impotence. According to the logistic regression classification table, sensitivity for psychogenic impotence was 778, specificity was. 750, positive predictive power was .789, and negative predictive power was .738. These results indicate that age and kind of onset proved to be significant predictors of psychogenic impotence and to have a good clinical functioning as both inclusion and exclusion criteria. These results suggest that a patient in his forties and with an acute onset of impotence should be firstly assessed from a psychological point of view; and on the opposite, a 50 year old patient with a gradual onset presents a rationale for a thorough clinical evaluation.