Usable definitions must be developed to provide consistency in the description of various sexual dysfunctions in men and women, as well as classifications of sexual disorders.

Descriptive and analytical epidemiological studies of various sexual dysfunctions backed by evidence-based medicine were examined. The conclusions and recommendation of the committee on Definitions, Classifications and Epidemiology of Sexual Dysfunction are summarized.

ABSTRACT
Introduction. Accurate estimates of prevalence/incidence are important in understanding the true burden of male and female sexual dysfunction and in identifying risk factors for prevention efforts.

Aim. To provide recommendations/guidelines concerning state-of-the-art knowledge for the epidemiology/risk factors of sexual dysfunctions in men and women.

Methods. An International Consultation in collaboration with the major urology and sexual medicine associations assembled over 200 multidisciplinary experts from 60 countries into 17 committees. Committee members established specific objectives and scopes for various male and female sexual medicine topics. The recommendations concerning state-of-the-art knowledge in the respective sexual medicine topic represent the opinion of experts from five continents developed in a process over a 2-year period. Concerning the Epidemiology/Risk Factors Committee, there were seven experts from four countries.

Main Outcome Measure. Expert opinion was based on grading of evidence-based medical litera-ture, widespread internal committee discussion, public presentation and debate.

Results. Standard definitions of male and female sexual dysfunctions are needed. The incidence rate for erectile dysfunction is 25–30 cases per thousand person years and increases with age. There are no parallel data for women’s sexual dysfunctions. The prevalence of sexual dysfunction increases as men and women age; about 40–45% of adult women and 20–30% of adult men have at least one manifest sexual dysfunction. Common risk factor categories associated with sexual dysfunction exist for men and women including: individual general health status, diabetes mellitus, cardiovascular disease, other genitourinary disease, psychiatric/psychological disorders, other chronic diseases, and socio-demographic conditions. Endothelial dysfunction is a condition present in many cases of erectile dysfunction and there are common etiological pathways for other vascular disease states.

Increasing physical activity lowers incidence of ED in males who initiate follow-up in their middle ages.

Conclusions. There is a need for more epidemiologic research in male and female sexual dysfunction.

Key Words. Prevalence/Incidence Sexual Dysfunction; Epidemiology Studies in Sexual Dysfunction; Desire Disorder; Arousal Disorder; Erectile Dysfunction; Orgasmic Disorder; Risk Factors; Co-morbidities

Definitions
Consistent uniform, universally acceptable definitions for sexual dysfunctions that affect men and women, which also include the degree of dysfunction, are necessary to compare epidemiological studies across the world. The following boldly highlighted definitions for the sexual dysfunctions for men and women (in principle consensus with Basson et al. [1]) are recommended.

Sexual interest/desire dysfunctions are diminished or absent feelings of sexual interest or desire, absent sexual thoughts or fantasies and a lack of responsive desire. There is some lessening of lack of interest with life cycle and relationship durations but these sexual interest/desire dysfunctions go beyond this normally expected decrease.