The unreliability of nocturnal penile tumescence recording as an outcome measurement in the treatment of organic impotence.

We investigated the degree of congruence between outcome measures used to evaluate pharmacological treatment of impotence. After a comprehensive multidisciplinary assessment 17 patients were treated with an adrenergic blocker during an 8-week interval. Nocturnal penile tumescence recordings were made before treatment (as part of the assessment procedure) and at its conclusion. As part of a larger study the use of nocturnal penile tumescence monitoring has been examined as a possible outcome measure. Patient and partner self-reports also were used to evaluate treatment outcome. A comparison of patient and partner self-reports with nocturnal penile tumescence records showed little agreement between the 2 measures. These findings suggest that despite its intuitive appeal as an index of erectile function nocturnal penile tumescence recording is not a reliable index of therapeutic effectiveness. Furthermore, these findings lend support to the hypothesis that nocturnal penile tumescence and sexual erections may be separate phenomena, perhaps under the control of different mechanisms.