International Index of Erectile Function-5 (IIEF-5)

Abstract

The International Index of Erectile Function-5 (IIEF-5), frequently identified as the Sexual Health Inventory for Men (SHIM), is a highly condensed and validated screening tool developed from the original 15-item International Index of Erectile Function (IIEF). Introduced in 1999, the IIEF-5 efficiently measures the presence and severity of Erectile Dysfunction (ED), a prevalent male sexual health concern. The instrument comprises five key items specifically addressing the erectile function domain, focusing on core aspects such as confidence in achieving an erection, penile rigidity, the ability to maintain the erection, and overall satisfaction derived from sexual activity over the preceding six months.

By using a simple summed score ranging from 5 to 25, the IIEF-5 allows clinicians and researchers to rapidly categorize patients into five distinct severity classifications, ranging from no ED to severe ED. Its brevity and strong psychometric profile have established it as the standard, non-invasive method for initial ED diagnosis and monitoring treatment efficacy globally.

Keywords

IIEF-5, SHIM, Erectile Dysfunction, Erectile Function, Impotence, Urological Assessment, Male Sexual Health, Questionnaire, Self-Report.

Authors

Rosen, R.C., Cappelleri, J.C., Smith, M.D., Lipsky, J., Pena, B.M.

Purpose

The primary mandate of the IIEF-5 is to provide a brief, yet highly reliable and precise measurement for the clinical diagnosis and severity stratification of Erectile Dysfunction (ED). By meticulously selecting and streamlining the items related strictly to erectile capacity from the original, multidimensional IIEF scale, the developers successfully minimized respondent burden while preserving robust psychometric integrity essential for clinical decision-making.

Beyond its utility in initial diagnostic screening, the scale is an indispensable tool in clinical research. It is extensively deployed in clinical trials and longitudinal studies to objectively track changes in erectile function status, assess the effectiveness of pharmacological agents or surgical interventions, and monitor the impact of systemic medical conditions on sexual health. The established, standardized scoring thresholds ensure consistency in reporting and comparison across various international healthcare and research settings.

Construct

The IIEF-5 is specifically designed to measure the psychological and physiological construct of Erectile Function. This construct represents the capacity of a male individual to achieve and sustain an erection adequate for satisfactory sexual performance. While the full IIEF assesses five domains (Erectile Function, Orgasm Function, Sexual Desire, Intercourse Satisfaction, and Overall Satisfaction), the IIEF-5 isolates the core functional deficit.

The five items probe both the physiological response (penile rigidity and maintenance ability) and the subjective, psychological component (confidence and satisfaction). The resulting total score serves as a concise numerical indicator of the respondent’s functional capacity and self-efficacy concerning erections over the defined six-month recall period. This concentrated focus makes the IIEF-5 a highly specific and powerful screening instrument strictly focused on ED severity, distinguishing it from broader measures of general sexual satisfaction or relationship quality.

Validity

The psychometric evaluation confirms that the IIEF-5 possesses strong criterion Validity. This is demonstrated by its exceptionally high correlation (typically reported correlations exceeding r = 0.90) with the dedicated Erectile Function domain of the original, longer IIEF scale. This strong statistical relationship confirms that the abridged, five-item version accurately captures the same fundamental construct as the more comprehensive measure from which it was derived.

Furthermore, the scale exhibits excellent discriminant validity, successfully differentiating between male patients clinically diagnosed with ED and those who are sexually healthy, based on independent clinical interviews and diagnostic protocols. Its proven high sensitivity and specificity establish the IIEF-5 as a highly reliable instrument capable of identifying clinically significant Erectile Dysfunction across diverse patient populations, including those with comorbidities like diabetes or cardiovascular disease.

Reliability

The IIEF-5 demonstrates robust measures of reliability, crucial for any diagnostic instrument. Specifically, it exhibits strong internal consistency. Academic studies consistently report high Cronbach’s alpha coefficients, often above 0.85, which confirms that the five constituent items are highly interrelated and cohere effectively to measure the single underlying construct of erectile function.

Additionally, the scale shows excellent test-retest reliability. This stability indicates that when a patient’s actual clinical status remains unchanged over a short period, the scores obtained from repeated administrations of the IIEF-5 remain stable. This stability is paramount for accurately monitoring the effectiveness of therapeutic interventions, ensuring that any subsequent changes in scores are attributable to genuine clinical improvement rather than inherent measurement error.

Factor Analysis

The original, comprehensive 25-item IIEF was structurally validated through Factor Analysis, which confirmed its multidimensional nature, consisting of five distinct, yet related, domains. In contrast, the IIEF-5 was intentionally developed to isolate and exclusively measure the primary factor: Erectile Function.

Subsequent confirmatory Factor Analysis conducted specifically on the five items of the IIEF-5 has consistently supported a unidimensional factor structure. This structural confirmation justifies the common practice of utilizing a simple, summed total score for the index, validating its utility as a straightforward, efficient, and specific measure of ED severity without the necessity for complicated sub-scoring or domain separation.

Instrument

Test Type: Self-report questionnaire / Screening tool

Format: 5-item Likert-scale format. Each item is scored on a scale ranging from 1 to 5, resulting in a minimum possible total score of 5 and a maximum possible total score of 25.

Language Available: The scale has been extensively translated, adapted, and validated across a wide range of global languages, including but not limited to Spanish, German, Chinese, and Japanese, ensuring broad applicability in international research.

Population Group: Adult males.

Age Group: Typically utilized for men aged 18 years and older, though its utility extends across the adult lifespan.

Population Details: The IIEF-5 is widely employed across general population health surveys and clinical settings. It is particularly valuable in clinical populations suffering from conditions frequently associated with sexual dysfunction, such as cardiovascular disease, metabolic syndrome (e.g., diabetes), and prostate conditions.

Test Methodology: Respondents are instructed to rate their experiences pertaining to erectile function over the past six months. The calculated total score (ranging from 5 to 25) is used to map the respondent’s status to established severity classifications:

• Score 1-7: Severe ED

• Score 8-11: Moderate ED

• Score 12-16: Mild-moderate ED

• Score 17-21: Mild ED

• Score 22-25: No ED

Keywords

Psychometrics, Sexual Health Inventory for Men, SHIM score, Urological Research, Clinical Trial Endpoint, Confidence, Penile Rigidity, Likert Scale.

Authors

Author ORCID Identifier: Not provided in source content.

Affiliation Email addresses: Not provided in source content.

Correspondence Address: Not provided in source content.

Permissions & Fee and Test Year

The International Index of Erectile Function-5 (IIEF-5) was published in 1999, serving as a validated, streamlined version of the original 1997 IIEF scale. Due to its commercial development (originally sponsored by Pfizer), the scale is proprietary. Researchers and organizations planning commercial use, large-scale clinical trials, or widespread implementation may be required to secure formal licensing agreements from the copyright holders.

While non-commercial academic use often operates under more flexible guidelines, specific usage protocols should always be consulted prior to administration. The instrument is often referenced by the name of its common distribution file, the SHIM score. The original PDF can be downloaded here: http://surgery.arizona.edu/sites/surgery.arizona.edu/files/pdf/SHIM%20score.pdf.

Reference’s

• Rosen, R.C., Cappelleri, J.C., Smith, M.D., Lipsky, J., Pena, B.M. (1999). 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. International Journal of Impotence Research; 11(6): 319 – 326.

• Rosen, R. C., Riley, A., Wagner, G., Osterloh, I. H., Kirkpatrick, J., & Mishra, A. (1997). The international index of erectile function (IIEF): A multidimensional scale for assessment of erectile dysfunction. Urology, 49, 822-830.

• Rosen, R.C., Althof, S.E., Giuliano, F. (2006). Research instruments for the diagnosis and treatment of patients with erectile dysfunction. Urology, 68: 6-16.

• Rhoden, E.L., Teloken, C., Sogari, P.R., Vargas, S.C. (2002). The use of the simplified International Index of Erectile Function (IIEF-5) as a diagnostic tool to study the prevalence of erectile dysfunction. Int J Impot Res., 14: 245-250.

• Additional information regarding the instrument can be found here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1476123/

Items of the International Index of Erectile Function-5 (IIEF-5)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

Over the past 6 months:

1. How do you rate your confidence that you could get and keep an erection?

• Very low
• Low
• Moderate
• High
• Very high

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

• Almost never or never
• A few times (much less than half the time)
• Sometimes (about half the time)
• Most times (much more than half the time)
• Almost always or always

3. During sexual intercourse, how often were you able to maintain your erection after you had penetrated your partner?

• Almost never of never
• A few times (much less than half the time)
• Sometimes (about half the time)
• Most times (much more than half the time)
• Almost always or always

4. During sexual intercourse, how difficult was it to maintain your erection to completion of intercourse?

• Extremely difficult
• Very difficult
• Difficult
• Slightly difficult
• Not difficult

5. When you attempted sexual intercourse, how often was it satisfactory for you?

• Almost never or never
• A few times (much less than half the time)
• Sometimes (about half the time)
• Most times (much more than half the time)
• Almost always or always