[Page 3112]Within the sexual dyad, adequate sexual functioning is typically important to a fulfilling sexual relationship and an overall sense of well-being. Inability to perform adequately—the basis of a sexual dysfunction—can cause personal distress, low self-efficacy, and relationship difficulties.

Prevalence, as defined by the National Institute of Mental Health, “is the proportion of a population who have (or had) a specific characteristic in a given time period—in medicine, typically an illness, a condition, or a risk factor.” Prevalence is often estimated on the basis of samples, as it is difficult to obtain prevalence rates based on population characteristics. Prevalence estimates are sometimes broken down by race, specific age groups, dysfunctional subtypes, education level, and other demographic characteristics. Incidence is a measure of the number of new ...