Interrelationship of Sildenafil Treatment Effects on the Physiological and Psychosocial Aspects of Erectile Dysfunction of Mixed or Organic Etiology

Introduction. In a previous paper using mediation modeling, the direct and indirect effects of sildenafil on erection maintenance were demonstrated. Objective. In an extension of this previous work, the historical psychosocial paradigm of ED, which focuses on performance anxiety, is tested by using mediation modeling to define the relationship of the physiological aspects (hardness and maintenance) and the associated psychosocial aspects (confidence, sexual relationship satisfaction, and performance anxiety) of ED. Methods. Statistical mediation analysis using the following outcomes from a double-blind placebo-controlled trial of fixed-dose sildenafil 100 mg or 50 mg: Erection Hardness Score; the 15-item International Index of Erectile Function (IIEF), including item 4 (frequency of erection maintenance after penetration) and item 5 (difficulty of erection maintenance to intercourse completion); the Self-Esteem And Relationship questionnaire; and the question, "Do you feel anxious about your next attempt at sexual intercourse?" Main Outcome Measures. Estimated percentages of direct and indirect effects of sildenafil on psychosocial aspects of ED (95% confidence intervals). Results. The model estimated that erection hardness mediated 43.7% (29.3%, 62.4%) of the effect of treatment onto confidence and 45.9% (32.2%, 61.8%) of the effect of treatment onto sexual relationship satisfaction, and that erection maintenance (using IIEF item 4 as a proxy) mediated 23.0% (10.1%, 39.1%) and 22.4% (10.1%, 36.5%), respectively. Similar results were obtained when IIEF item 5 was used as the proxy for measurement of maintenance. Of all possible paths to performance anxiety, only that from treatment via confidence was statistically significant, mediating an estimated 88.6% (55.5%, 146.2%; item 4 model) or 74.9% (47.0%, 121.0%; item 5 model) of the effect of treatment onto anxiety. The direct path to anxiety from treatment was not statistically significant. Conclusions. In men treated with sildenafil for ED, performance anxiety might be ameliorated by improved confidence. Improved confidence might be mainly mediated via increased erection hardness. Althof SE, Berner MM, Goldstein I, Claes HIM, Cappelleri JC, Bushmakin AG, Symonds T, and Schnetzler G. Interrelationship of sildenafil treatment effects on the physiological and psychosocial aspects of erectile dysfunction of mixed or organic etiology. J Sex Med 2010;7:3170-3178.