A comparison of the international index of erectile function and measurement of nocturnal penile tumescence using the Androscan MIT device

Purpose: To determine the agreement between two erectile dysfunction (ED) diagnostic methods, International Index of Erectile Function-15 (IIEF-15) questionnaire and “Androscan MIT” night penile tumescence recorder. Materials and Methods: An assessment of ED in 40 patients (age, 25–60 years) was performed using the “Androscan MIT” device and IIEF-15 questionnaire (erectile domain). Cohen's kappa coefficient and receiver operating characteristic (ROC) analyses were used to examine the difference between “Androscan MIT” and IIEF-15 questionnaire results. During ROC-analyses “Androscan MIT” results were considered the gold standard for ED diagnosis. Results: “Androscan MIT” results had a significant but weak positive correlation with IIEF-15 questionnaire (kappa value = 0.333, P < 0.01). Based on the ROC-analyses, it was found that the sensitivity and specificity of the IIEF-15 questionnaire for severe ED according to “Androscan MIT” were 100% and 55.9%, respectively. The sensitivity and specificity of the IIEF-15 questionnaire for moderate ED according to “Androscan MIT” were 63.2% and 57.1%, and for mild ED, 23.1% and 33.3% respectively. The lowest accuracy of the IIEF-15 questionnaire was for patients with normal erectile function (sensitivity and specificity were 0% and 44.7%, respectively). Conclusion: The agreement between the objective and subjective diagnosis of ED remains low. At the same time, the lower severity of ED according to “Androscan MIT” is associated with less diagnostic value of IIEF-15.