International Index of Erectile Function-6 (IIEF-6)

Purpose and Primary Use:

The IIEF-6 questions are a subset of the original, comprehensive International Index of Erectile Function (IIEF-15).

• The IIEF-15 was developed and validated in 1996-1997 by a team of researchers, notably Rosen et al., in conjunction with the clinical trial program for sildenafil (Viagra). The goal was to create a robust and reliable self-report questionnaire for assessing male sexual function, particularly in the context of erectile dysfunction (ED) and its treatment.
• The full IIEF-15 assesses five different domains of male sexual function:
  • Erectile Function (6 items)
  • Orgasmic Function (2 items)
  • Sexual Desire (2 items)
  • Intercourse Satisfaction (3 items)
  • Overall Satisfaction (2 items)

Scoring:

The IIEF-6 specifically comprises the 6 questions from the "Erectile Function" domain of the original IIEF-15. These questions were identified as being the most crucial for evaluating the presence and severity of erectile dysfunction.

Question 1: How often were you able to get an erection during sexual activity?

0 points: No sexual activity

1 points: Almost never or never

2 points: A few times (much less than half the time)

3 points: Sometimes (about half the time)

4 points: Most times (much more than half the time)

5 points: Almost always or always

Question 2: When you had erections with sexual stimulation, how often were your erections hard enough for penetration?

0 points: No sexual activity

1 points: Almost never or never

2 points: A few times (much less than half the time)

3 points: Sometimes (about half the time)

4 points: Most times (much more than half the time)

5 points: Almost always or always

Question 3: When you attempted intercourse, how often were you able to penetrate (enter) your partner?

0 points: Did not attempt intercourse

1 points: Almost never or never

2 points: A few times (much less than half the time)

3 points: Sometimes (about half the time)

4 points: Most times (much more than half the time)

5 points: Almost always or always

Question 4: During sexual intercourse, how often were you able to maintain your erection after you had penetrated (entered) your partner?

0 points: Did not attempt intercourse

1 points: Almost never or never

2 points: A few times (much less than half the time)

3 points: Sometimes (about half the time)

4 points: Most times (much more than half the time)

5 points: Almost always or always

Question 5: During sexual intercourse, how difficult was it to maintain your erection to completion of intercourse?

0 points: Did not attempt intercourse

1 points: Extremely difficult

2 points: Very difficult

3 points: Difficult

4 points: Slightly difficult

5 points: Not difficult

Question 6: How do you rate your confidence that you could get and keep an erection?

1 points: Very low

2 points: Low

3 points: Moderate

4 points: High

5 points: Very high

Similarly, the IIEF-5 (Sexual Health Inventory for Men - SHIM) is an even shorter, 5-item version, which also draws heavily from the erectile function domain, often incorporating 4 of the 6 erectile function questions and one question related to satisfaction. The SHIM focuses on key aspects of erectile function, including confidence, erection hardness, ability to maintain erection, and satisfaction with intercourse.

• Rosen RC, Cappelleri JC, Smith MD, Lipsky J, Peña BM. Development of an abridged, 5-item version of the International Index of Erectile Function (IIEF-5) as a diagnostic tool for erectile dysfunction. Int J Impot Res. 1999;11(6):319-326. doi:10.1038/sj.ijir.3900472.

To summarize, the IIEF-6 questions did not appear in isolation but were carefully selected and validated as part of the broader development of the International Index of Erectile Function, which has become a "gold standard" in the assessment of male sexual health.

Scoring Interpretation for IIEF-6 (Total Score Range: 1-30):

After summing the scores from all six questions, the total score indicates the severity of erectile dysfunction:

• 26-30: No erectile dysfunction (or minimal ED, depending on the source)
• 18-25: Mild erectile dysfunction
• 11-17: Moderate erectile dysfunction
• 1-10: Severe erectile dysfunction

If "no sexual activity" or "did not attempt intercourse" is selected, the following result(s) will appear:

• Caution: One or more responses indicates "no sexual activity"
• Caution: One or more responses indicates "did not attempt intercourse"

Critically interpret the raw score if there are "0" answers. 

• If a low score is largely due to "0" responses for questions where the patient states they had no opportunity or chose not to engage in sexual activity/intercourse for reasons unrelated to their erectile function, then the IIEF-6 score alone may not accurately reflect their erectile dysfunction status.
• In a clinical setting, simply relying on the numerical cutoff for ED severity without considering the context of "0" answers can lead to misdiagnosis and inappropriate treatment recommendations.
• This recent paper from Memorial Sloan Kettering Cancer Center (MSKCC) discusses practical issues with the IIEF-6, particularly concerning "no sexual activity" responses, and proposes modifications to improve its accuracy in individual patient assessment.
• This is another very recent and important study that validates a modified scoring approach for the IIEF-6 to address the "no sexual intercourse" issue in a population-based cohort, providing evidence for a more accurate assessment.

Use the IIEF-6 as a screening tool to prompt further discussion. 

• If a patient scores low due to "0" answers, it's an opportunity for the clinician to delve deeper into their sexual history, desires, and current life circumstances.
• Follow-up questions: If a patient answers "no sexual activity," a subsequent question might ask for the reason (e.g., "If you answered 'no sexual activity' or 'did not attempt intercourse,' was this due to: a) lack of confidence/ability, b) lack of a willing partner, c) other (please specify)?").

If a person answers "no sexual activity" or "did not attempt intercourse" for certain questions, those responses typically score 0, but it's crucial to consider the reason for no activity. If it's due to lack of opportunity or preference, rather than inability, the interpretation might be adjusted by a clinician.

Related Decision Support Tools:

The IIEF-6 is derived from the more comprehensive International Index of Erectile Function (IIEF), a 15-item questionnaire that assesses multiple domains of male sexual function, including erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction. While the IIEF-6 provides a quick assessment of ED, the full IIEF may be used for a more detailed evaluation, particularly in research settings or complex clinical cases.

Please answer the following 6 questions based on your experiences over the past 4 weeks.