Context While recent pharmacological advances have generated
increased public interest and demand for clinical services regarding
erectile dysfunction, epidemiologic data on sexual dysfunction are
relatively scant for both women and men.
Objective To assess the prevalence and risk of experiencing sexual
dysfunction across various social groups and examine the determinants
and health consequences of these disorders.
Design Analysis of data from the National Health and Social Life
Survey, a probability sample study of sexual behavior in a
demographically representative, 1992 cohort of US adults.
Participants A national probability sample of 1749 women and 1410
men aged 18 to 59 years at the time of the survey.
Main Outcome Measures Risk of experiencing sexual dysfunction as
well as negative concomitant outcomes.
Results Sexual dysfunction is more prevalent for women (43%) than
men (31%) and is associated with various demographic characteristics,
including age and educational attainment. Women of different racial
groups demonstrate different patterns of sexual dysfunction.
Differences among men are not as marked but generally consistent with
women. Experience of sexual dysfunction is more likely among women and
men with poor physical and emotional health. Moreover, sexual
dysfunction is highly associated with negative experiences in sexual
relationships and overall well-being.
Conclusions The results indicate that sexual dysfunction is an
important public health concern, and emotional problems likely
contribute to the experience of these problems.
Sexual dysfunctions
are characterized by disturbances in sexual desire and in the
psychophysiological changes associated with the sexual response cycle
in men and women.1 Despite increasing demand for clinical
services and the potential impact of these disorders on interpersonal
relationships and quality of life,2,3 epidemiologic data
are relatively scant. Based on the few available community studies, it
appears that sexual dysfunctions are highly prevalent in both sexes,
ranging from 10% to 52% of men and 25% to 63% of
women.4-6 Data from the Massachusetts Male Aging
Study7 (MMAS) showed that 34.8% of men aged 40 to 70 years
had moderate to complete erectile dysfunction, which was strongly
related to age, health status, and emotional function. Erectile
dysfunction has been described as an important public health problem by
a National Institutes of Health Consensus Panel,8 which
identified an urgent need for population-based data concerning the
prevalence, determinants, and consequences of this disorder. Even less
is known about the epidemiology of female sexual dysfunction.
Professional and public interest in sexual dysfunction has
recently been sparked by developments in several areas. First, major
advances have occurred in our understanding of the neurovascular
mechanisms of sexual response in men and women.9-11 Several
new classes of drugs have been identified that offer significant
therapeutic potential for the treatment of male erectile
disorder,12-14 while other agents have been proposed for
sexual desire and orgasm disorders.15,16 Availability of
these drugs could increase dramatically the number of patients seeking
professional help for these problems. Epidemiologic data would be of
obvious value in developing appropriate service delivery and resource
allocation models. Additionally, changing cultural attitudes and
demographic shifts in the population have highlighted the pervasiveness
of sexual concerns in all ethnic and age groups.
The present study addresses these issues by analyzing data on sexual
dysfunction from the National Health and Social Life Survey (NHSLS), a
study of adult sexual behavior in the United States.17
Sampling, data collection, and response analysis were all conducted
under highly controlled conditions. This unique data source provides
extensive information on key aspects of sexual behavior, including
sexual problems and dysfunction, health and lifestyle variables, and
sociocultural predictors. Prior analyses of sexual dysfunction, using
NHSLS data, are limited, presenting basic
prevalence rates across demographic characteristics and indicators of
overall health and well-being.17(pp368-374) The
present study, in contrast, uses multivariate techniques to estimate
relative risk (RR) of sexual dysfunction for each demographic
characteristic as well as for key risk factors.
The NHSLS, conducted in 1992, is a national probability sample of 1410
men and 1749 women between the ages of 18 and 59 years living in
households throughout the United States. It accounts for about 97% of
the population in this age range—roughly 150 million Americans. It
excludes people living in group quarters such as barracks, college
dormitories, and prisons, as well as those who do not know English well
enough to be interviewed. The sample completion rate was greater than
79%. Checks with other high-quality samples (eg, US Census Bureau's
Current Population Survey) indicated that the NHSLS succeeded in
producing a truly representative sample of the population. Each
respondent was surveyed in person by experienced interviewers, who
matched respondents on various social attributes, for an interview
averaging 90 minutes. Extensive discussion of the sampling design and
evaluations of sample and data quality are found in the book by Laumann
et al.17(pp35-73,549-605)
Sexual dysfunction was indexed in this study according to 7 dichotomous
response items, each measuring presence of a critical symptom or
problem during the past 12 months.17(p660) Response items included: (1) lacking desire for sex; (2) arousal
difficulties (ie, erection problems in men, lubrication difficulties in
women); (3) inability achieving climax or ejaculation; (4) anxiety
about sexual performance; (5) climaxing or ejaculating too rapidly; (6)
physical pain during intercourse; and (7) not finding sex pleasurable.
The last 3 items were asked only of respondents who were sexually
active during the prior 12-month period. Taken together, these items
cover the major problem areas addressed in the Diagnostic and
Statistical Manual of Mental Disorders, Fourth Edition1
classification of sexual dysfunction. Self-reports about sexual
dysfunctions, especially in face-to-face interviews, are subject to
underreporting biases arising from personal concerns about social
stigmatization. Moreover, there may be systematic biases in
underreporting related to particular attributes of the respondents. For
example, older or less educated women or younger Hispanic men might be
more reluctant to report sexual problems. Lack of privacy during
interviews could also result in underreporting. However, analyses (not
reported herein) indicate that reporting biases due to lack of privacy
are negligible in NHSLS data.17(pp564-570)
A latent class analysis (LCA) was used to evaluate the syndromal
clustering of individual sexual symptoms. Latent class analysis is a
statistical method well suited
for grouping categorical data into latent
classes18,19 and has a number of medical applications, such
as evaluation of diagnostic systems20-23 and generation of
epidemiologic estimates using symptom data.24,25 Latent
class analysis tests whether a latent variable, specified as a set of
mutually exclusive classes, accounts for observed covariation among
manifest, categorical variables. A more detailed discussion of this
method is available on request from the authors. Since diagnostic
criteria for disorders of sexual dysfunction involve a complex of
symptoms, we used LCA for grouping symptoms into categories. These
categories, then, represent a typology of disorders for sexual
dysfunction found in the US population, indicating both prevalence and
types of symptoms.
We analyzed only those respondents reporting at least 1 partner in the
prior 12-month period. Respondents who were sexually inactive during
this period were excluded. This procedure may limit our results because
excluded respondents may have avoided sex because of sexual problems.
However, this procedure was necessary to ensure that each respondent
answered all the symptom items since 3 items were asked only of
sexually active respondents. A total of 139 men and 238 women were
excluded on this basis. Excluded men were more likely to be single and
have lower levels of education. We expect that this will bias our
estimates of prevalence of sexual dysfunction downward since sexually
inactive men generally reported higher rates of symptoms. Excluded
women tended to be older and single. The exclusion of these women is
likely to bias our estimates of the prevalence of sexual dysfunction
upward given that these women tended to report lower rates.
Analyses performed in this study were made by use of logistic and
multinomial logistic regression. For assessing the prevalence of
symptoms across demographic characteristics, we performed logistic
regressions for each symptom. This approach produced adjusted odds
ratios (ORs), which indicate the odds that members of a given social
group (eg, never married) reported the symptom relative to a reference
group (eg, currently married), while controlling for other demographic
characteristics. Demographic characteristics included respondent's
age, marital status, educational attainment level, and race and
ethnicity. Next, while controlling for these characteristics, we
estimated adjusted ORs using multinomial logistic regressions for 3
sets of risk factors, each modeled separately in a nonnested manner.
Risk factors associated with health and lifestyle included alcohol
consumption, prior contraction of sexually transmitted diseases (STDs),
presence of urinary tract symptoms, circumcision, health status, and
experience of emotional or stress-related problems. Social status
variables included change in income level and normative orientation,
indexed by how liberal or conservative respondents' attitudes were
toward sex. Risk factors associated with sexual experience included the
number of lifetime sex partners, frequency of sex, how often
respondents think about sex, frequency of masturbation, same sex
contact, and experience in potentially traumatic events such as
adult-child contact, forced sexual contact, sexual harassment, and
abortion. Finally, we conducted a set of logistic regressions that used
the categories of sexual dysfunction as predictor variables. These
models measured the association between experience of dysfunction
categories and quality-of-life concomitants, which included being
satisfied personally and in relationships. We stress that concomitant
outcomes cannot be causally linked as an outcome of sexual dysfunction.
Latent class analyses were performed using maximum likelihood latent
structure analysis.26 All logistic regressions used STATA
version 5.0.27 Information regarding variable construction,
LCA methods, and data quality are available from the authors.
Prevalence of Sexual Problems
Use of NHSLS data allows for calculating national prevalence estimates
of sexual problems for adult women and
men. While NHSLS data on critical symptoms do not
connote a clinical definition of sexual dysfunction, their prevalence
does provide important information about their extent and differential
distribution among the US population.
Table 1 and Table 2 analyze the
prevalencing sexual problems across selected demographic
characteristics. For women, the prevalence of sexual problems tends to
decrease with increasing age except for those who report trouble
lubricating. Increasing age for men is positively associated with
experience of erection problems and lacking desire for sex. The oldest
cohort of men (ages 50-59 years) is more than 3 times as likely to
experience erection problems (95% confidence interval [CI], 1.8-7.0)
and to report low sexual desire (95% CI, 1.6-5.4) in comparison to men
aged 18 to 29 years. The prevalence of sexual problems also varies
significantly across marital status. Premarital and postmarital
(divorced, widowed, or separated) statuses are associated with elevated
risk of experiencing sexual problems. Nonmarried women are roughly 112 times more likely to have climax problems (95% CI, 1.0-2.1
and 1.2-2.3, respectively) and sexual anxiety (95% CI, 1.0-2.4 and
1.1-2.4, respectively) than married women. Similarly, nonmarried men
report significantly higher rates for most symptoms of sexual
dysfunction than married men. Thus, married women and men are clearly
at lower risk of experiencing sexual symptoms than their nonmarried
counterparts.
High educational attainment is negatively associated with experience of
sexual problems for both sexes. These differences are especially marked
between women who do not have high school diplomas and those who have
college degrees. Controlling for other demographic characteristics,
women who have graduated from college are roughly half as likely to
experience low sexual desire (95% CI, 0.3-0.8), problems achieving
orgasm (95% CI, 0.3-0.7), sexual pain (95% CI, 0.3-1.0), and sexual
anxiety (95% CI, 0.3-1.0) as women who have not graduated from high
school. Male college graduates are only two thirds (95% CI, 0.4-1.0)
as likely to report climaxing too early and half as likely to report
nonpleasurable sex (95% CI, 0.2-0.9) and sexual anxiety (95% CI,
0.3-0.8) than men who do not have high school diplomas. Overall, women
and men with lower educational attainment report less pleasurable
sexual experience and raised levels of sexual anxiety.
The association between race and ethnicity and sexual problems is more
variable. Black women tend to have higher rates of low sexual desire
and experience less pleasure compared with white women, who are more
likely to have sexual pain than black women. Hispanic women, in
contrast, consistently report lower rates of sexual problems.
Differences between men are not as marked but are generally consistent
with what women experience. Indeed, although the
effects of race and ethnicity are fairly modest among both sexes,
blacks appear more likely to have sexual problems while Hispanics are
less likely to have sexual problems, across the categories of sexual
dysfunction.
The results of LCA allow for analyzing risk factors and
quality-of-life concomitants in relation to categories of sexual
dysfunction, rather than individual symptoms. Analyses presented in
Table 3,
Table 4 , and
Table 5 use the results of LCA instead of
individual symptoms. These results indicate that the clustering of
symptoms according to syndrome can be represented by 4 categories for
women as well as for men. Latent class analysis also estimates the size
of each class as a proportion of the total sample, a result
corresponding to prevalence of categories of sexual dysfunction in the
US population. Finally, LCA identifies each class's symptoms,
indicating the likelihood that respondents in that class will
exhibit a given symptom, thus providing researchers with
information about what elements characterize each category. Although
not equivalent to clinical diagnosis, this approach offers a
statistical representation of sexual dysfunction.
For women, the 4 categories identified by LCA roughly correspond to
major disorders of sexual dysfunction as outlined by the
Diagnostic and Statistical Manual of Mental Disorders, Fourth
Edition.1 These include an unaffected group (58%
prevalence), a low sexual desire category (22% prevalence), a category
for arousal problems (14% prevalence), and a group with sexual pain
(7% prevalence). Similarly, a large proportion of men (70%
prevalence) constitutes an unaffected population. The remaining
categories consist of premature ejaculation (21% prevalence), erectile
dysfunction (5% prevalence), and low sexual desire (5% prevalence).
Overall, the results of LCA show that the total prevalence of sexual
dysfunction is higher for women than men (43% vs 31%).
Table 3 and
Table 4 present multinomial logistic regressions on
categories of sexual dysfunction. Adjusted ORs indicate the relative
risk of experiencing a given category of sexual dysfunction vs
reporting no problems for each risk factor, while controlling for other
characteristics. With regard to health and lifestyle risk factors,
those who experience emotional or stress-related problems are more
likely to experience sexual dysfunctions defined in each of the
categories. In contrast, health problems affect women and men
differently. Men with poor health have elevated risk for all categories
of sexual dysfunction, whereas this factor is only associated with
sexual pain for women. The presence of urinary tract symptoms appears
to impact sexual function only (eg, arousal and pain disorders for
women or erectile dysfunction for men). Finally, having had an STD,
moderate to high alcohol consumption, and circumcision generally do not
result in increased odds of experiencing sexual dysfunction.
Social status variables, which measure an individual's
socioeconomic and normative position relative to other persons, assess
how sociocultural position affects sexual function. Deterioration in
economic position, indexed by falling household income, is generally
associated with a modest increase in risk for all categories of sexual
dysfunction for women but only erectile dysfunction for men. Normative
orientation does not appear to have any impact on sexual dysfunction
for women; men with liberal attitudes about sex, in contrast, are
approximately 134 times more likely to experience premature
ejaculation (95% CI, 1.2-2.5).
Finally, various aspects of sexual experience result in an increased
risk of sexual dysfunction. Sexual history, indicated by having more
than 5 lifetime partners and by masturbation practices, does not
increase relative risk for either women or men. Women with low sexual
activity or interests, however, have elevated risk for low sexual
desire and arousal disorders. Men do not exhibit similar
associations. The impact of potentially traumatic sexual events is
markedly different for women and men. Women respondents reporting any
same-sex activity are not at higher risk for sexual dysfunction, while
men are. Men reporting any same-sex activity are more than twice as
likely to experience premature ejaculation (95% CI, 1.2-3.9) and low
sexual desire (95% CI, 1.1-5.7) than men who have not. Arousal
disorder appears to be highly associated in women who have experienced
sexual victimization through adult-child contact or forced sexual
contact. Similarly, male victims of adult-child contact are 3 times as
likely to experience erectile dysfunction (95% CI, 1.5-6.6) and
approximately 2 times as likely to experience premature ejaculation
(95% CI, 1.2-2.9) and low sexual desire (95% CI, 1.1-4.6) than those
who have not been victims of adult-child contact. Finally, men who have
sexually assaulted women are 312 times as likely to report
erectile dysfunction (95% CI, 1.0-12.0). Indeed, traumatic sexual acts
continue to exert profound effects on sexual functioning, some effects
lasting many years beyond the occurrence of the original event.
Quality-of-Life Concomitants
The experience of sexual dysfunction is highly associated with a
number of unsatisfying personal experiences and relationships. Table 5
highlights the associations of categories of sexual dysfunction with
emotional and physical satisfaction with sexual partners and with
feelings of general happiness. However, no causal order should be
assumed since quality-of-life indicators are concomitant outcomes of
sexual dysfunction. For women, all categories of sexual
dysfunction—low sexual desire, arousal disorder, sexual pain—have
strong positive associations with low feelings of physical and
emotional satisfaction and low feelings of happiness. Similar to women,
men with erectile dysfunction and low sexual desire experience
diminished quality of life, but those with premature ejaculation are
not affected. In brief, experience of sexual dysfunction is generally
associated with poor quality of life; however, these negative outcomes
appear to be more extensive and possibly more severe for women than
men. In an examination of help-seeking behavior (analysis not shown
here, but available on request), we found that roughly 10% and 20% of
these afflicted men and women, respectively, sought medical
consultation for their sexual problems.
Demographic factors such as age are strongly predictive of sexual
difficulties, particularly erectile dysfunction. Sexual problems are
most common among young women and older men. Several factors may
explain these differential rates. Since young women are more likely to
be single, their sexual activities involve higher rates of partner
turnover as well as periodic spells of sexual inactivity. This
instability, coupled with inexperience, generates stressful sexual
encounters, providing the basis for sexual pain and anxiety. Young men
are not similarly affected. Older men are more likely to have trouble
maintaining or achieving an erection as well as to lack an interest in
sex. Low sexual interest and erection problems are age-dependent
disorders, possibly resulting from physiological changes associated
with the aging process. Indeed, our results are consistent with those
generated by the MMAS, which determined that 9.6% of its sample
experienced complete impotence and showed a strong age association
increasing from 5% to 15% between subject ages of 40 and 70
years.7
Other factors such as poor health and lifestyle are
differentially predictive across demographic groups. While nonmarital
status is associated with lower overall well-being, part of the
higher risk of sexual dysfunction probably stems from differences
in sexual lifestyles. Similarly, elevated risks associated with
low educational attainment and minority status attest to the fact that
better-educated individuals are healthier and have
lifestyles that are physically and emotionally less
stressful. To understand the factors that predispose individuals to
sexual dysfunction, we should analyze risk factors.
The NHSLS data indicate that emotional and stress-related
problems among women and men generate elevated risk of experiencing
sexual difficulties in all phases of the sexual response cycle. While
we caution that the causal order of this relationship is uncertain,
these results suggest that psychosocial disturbances affect sexual
functioning. This does not imply that the impact of poor health is
negligible; in fact, the opposite is demonstrated since age, health
problems, and urinary tract infections result in elevated risk of
experiencing sexual dysfunction. Rather, both physiological and
psychological statuses are independent factors that affect sexual
functioning.
Given the salience of emotional distress on sexual dysfunction, we
examine 2 underlying sources of psychosocial stress: social status and
sexual trauma. The NHSLS data clearly suggest that deteriorating social
position negatively affects sexual functioning. Deterioration in
economic position induces higher levels of stress, which in turn
affects sexual functioning, a result more pervasive among women than
men. Future research should be directed toward mapping the social
distribution of emotional distress.
With respect to possibly traumatic sexual experiences, our
findings are complex and show distinct differences between sexes but
clearly provide evidence that these experiences are sources of
psychosocial stress. First, we found that the impact of same-sex
activity is relevant for men but not women. The source of this
difference may be rooted in the
subjective meaning of these sex acts, because many
male-to-male encounters have involved adult-child contact. We should
note that these results assess the impact of historical instances of
same-sex activity, not the relationship between homosexuality and
sexual problems. Similarly, indicators for sexual victimization show
strong effects in persons of both sexes. For women, adult-child contact
or forced sex, both generally perpetrated by men, results in increased
risk of experiencing arousal disorders. These results support the view
that sexual traumas induce lasting psychosocial disturbances, which
ultimately affect sexual functioning.28 Similarly, men who were touched sexually before puberty also are more likely to experience
all categories of sexual dysfunction. In short, both female and male
victims of unwanted sexual contact exhibit long-term changes in sexual
functioning.
While the causal relationship between quality-of-life concomitants and
sexual dysfunction also remains to be investigated, the strong
associations observed in NHSLS data suggest that sexual dysfunction is
a largely uninvestigated yet significant public health problem. Recent
advances in therapy for erectile dysfunction may increase quality of
life for some men. However, since low well-being is strongly associated
with female sexual problems, researchers should focus on identifying
the consequences of these problems as well as developing appropriate
therapies. With the affected population rarely receiving medical
therapy for sexual dysfunction, service delivery efforts should be
augmented to target high-risk populations.
This report provides the first population-based assessment of
sexual dysfunction in the half-century since Kinsey et
al.29,30 The results from the NHSLS indicate that sexual
problems are widespread in society and are influenced by both
health-related and psychosocial factors. The role of the latter implies
that stress-inducing events, due to either individual or social
sources, can affect sexual functioning in both men and women. Differing
patterns of sexual dysfunction were observed across sex, age, and
demographic groups, highlighting the need for further research on
etiologic mechanisms. With the strong association between sexual
dysfunction and impaired quality of life, this problem warrants
recognition as a significant public health concern.
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