About the International Index of Erectile Function - 6 (IIEF-6)
The International Index of Erectile Function - 6 (IIEF-6) is a validated patient-reported outcome measure specifically designed to assess erectile function. It is a shortened version of the full 15-item IIEF questionnaire, focusing exclusively on the erectile function domain. The IIEF-6 has demonstrated excellent psychometric properties, including high internal consistency (Cronbach's alpha > 0.90), strong test-retest reliability, and good construct validity. It is responsive to treatment-related changes and has been validated across multiple languages and cultures. The questionnaire is widely used in clinical practice, research studies, and pharmaceutical trials to assess erectile dysfunction severity and monitor treatment outcomes.
Medical Specialties
Clinical Indications
Developer Information
The International Index of Erectile Function (IIEF) was developed by Dr. Raymond C. Rosen and colleagues, with the original 15-item version published in 1997. The IIEF-6 is a shortened version focusing specifically on erectile function, extracted from the full IIEF questionnaire. The development and validation of the IIEF-6 was based on psychometric analysis of the full IIEF, identifying the 6 questions that best capture the erectile function domain.
Copyright & Licensing
The IIEF and IIEF-6 are proprietary instruments. Copyright and licensing information should be verified with the developers or publishers. The IIEF is widely used in clinical practice and research, and validated translations are available in multiple languages. Use in commercial applications may require permission or licensing.
Administration Instructions
Please answer the following questions about your sexual function over the past 4 weeks. Be honest and choose the answer that best describes your experience. All questions refer to your experiences during the past 4 weeks.
Scoring Methodology
The IIEF-6 consists of 6 questions, each scored on a scale from 0 to 5. Questions 1-4 assess the frequency of erections, erection firmness, ability to penetrate, and ability to maintain erection. Question 5 assesses difficulty maintaining erection to completion (scored 0-5, where higher scores indicate less difficulty). Question 15 assesses overall satisfaction with sex life (scored 0-5). The Total Score is the sum of all 6 questions, ranging from 0-30. All 6 questions must be answered to calculate the total score. Higher scores indicate better erectile function. The IIEF-6 Total Score is classified as follows: No ED (26-30), Mild ED (22-25), Mild to Moderate ED (17-21), Moderate ED (11-16), Severe ED (6-10), Very Severe ED (0-5).
Meaningful Change Threshold
A change of 4-6 points in the IIEF-6 Total Score is considered clinically meaningful. The minimal clinically important difference (MCID) has been established at approximately 4-5 points. Changes of 2-3 points may represent small but potentially meaningful improvements, while changes of 7+ points represent substantial improvements. The IIEF-6 is highly responsive to treatment-related changes, making it valuable for monitoring treatment outcomes in both clinical practice and research settings.
Score Interpretation
Understanding what your score means
very severe ed
0 - 5Very severe erectile dysfunction - Patient is almost never or never able to achieve or maintain erections sufficient for sexual activity.
severe ed
6 - 10Severe erectile dysfunction - Patient experiences substantial difficulties with erectile function, rarely able to achieve or maintain erections sufficient for penetration.
moderate ed
11 - 16Moderate erectile dysfunction - Patient experiences significant difficulties with erectile function, with erections sufficient for penetration occurring less than half the time.
mild to moderate ed
17 - 21Mild to moderate erectile dysfunction - Patient experiences noticeable difficulties with erectile function, with erections sufficient for penetration occurring about half the time.
mild ed
22 - 25Mild erectile dysfunction - Patient experiences occasional difficulties with erectile function but is generally able to achieve and maintain erections sufficient for sexual activity most of the time.
no ed
26 - 30No erectile dysfunction - Patient reports normal erectile function with consistent ability to achieve and maintain erections sufficient for satisfactory sexual activity.
Subscales
This questionnaire measures multiple dimensions
Clinical Limitations & Considerations
The IIEF-6 focuses exclusively on erectile function and does not assess other domains of sexual function such as orgasmic function, sexual desire, or overall satisfaction (beyond the single satisfaction question). The questionnaire requires patients to have attempted sexual activity within the past 4 weeks, which may limit its applicability to certain patient populations. Cultural and language differences may affect interpretation, and validated translations should be used for non-English speaking populations. The IIEF-6 should be used as part of a comprehensive clinical assessment rather than as the sole basis for diagnosis or treatment decisions. Patients who have not attempted sexual activity may score 0 on multiple items, which may not accurately reflect their erectile function potential.
Supporting Literature
Key validation and development studies for the International Index of Erectile Function - 6 (IIEF-6)
- 1
The international index of erectile function (IIEF): a multidimensional scale for assessment of erectile dysfunction
Rosen RC, Riley A, Wagner G, Osterloh IH, Kirkpatrick J, Mishra A
Urology, 1997
- 2
Development and evaluation of an abridged, 5-item version of the International Index of Erectile Function (IIEF-5) as a diagnostic tool for erectile dysfunction
Rosen RC, Cappelleri JC, Smith MD, Lipsky J, Peña BM
International Journal of Impotence Research, 1999
Related Outcome Measures
Other clinical questionnaires for similar specialties and conditions
Sexual Quality of Life – Male (SQoL-M)
An 11-item questionnaire assessing the impact of sexual dysfunctions on men's quality of life. Evaluates emotional and psychological aspects including confidence, anxiety, and relationship concerns.
Peyronie's Disease Questionnaire (PDQ)
A 15-item questionnaire assessing the psychosexual impact of Peyronie's Disease. Comprises three subscales: psychological and physical symptoms, penile pain, and symptom bother.
Patient's Global Impression of Improvement (PGI-I)
A single-item questionnaire assessing a patient's perception of change in their condition following treatment. Uses a 7-point scale from "Very much improved" to "Very much worse".
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