- International Index of Erectile Function, 5-item version (IIEF-5). Five questions related to erectile function, orgasmic function, sexual desire, satisfaction with sexual relations and overall satisfaction. In addition, this has a high sensitivity and specificity for detecting changes in erectile function in response to treatment. The ED grade is scored on a scale of 0 to 25 points, where: 5-7 is severe, 8-11 is moderate, 12-16 is mild to moderate; 17-21 is average; and 22-25 ED does not exist (28) (Appendix 2).