Are aspects of study design associated with the reported prevalence of female sexual difficulties?

Objective: To investigate associations between the prevalence of sexual  difficulties reported in published studies and design features of those studies to determine if differences in design contribute to variation in prevalence estimates.
Design: Systematic review, multivariate analysis.
Setting: Studies published internationally in English.
Patient(s): Not applicable.
Intervention(s): None.
Main Outcome Measure(s): Prevalence estimates of difficulty with desire, arousal, orgasm, and sexual pain reported in published studies.
Result(s): Our systematic literature search identified 1,380 publications. Fifty-five studies met our inclusion criteria (reporting prevalence, sample size and response rate, sample size greater than 100, not clinic based). Reported prevalence of sexual difficulty varied across studies (up to tenfold). Eleven aspects of research conduct in these studies were included in our multivariate analysis as explanatory variables. Five aspects of study design and conduct (data collection procedures, inclusion criteria, duration of sexual difficulty recorded, sample size, and response rate) were associated with the reported prevalence of at least one type of sexual difficulty independently of likely predictors of true variation in prevalence: study location, study year, and age range of participants.
Conclusion(s): This review provides evidence that study design may influence reported prevalence estimates of female sexual difficulties and contribute to the wide variation in published estimates.

Risk factors for female sexual dysfunction in the general population : exploring factors associated with low sexual function and sexual distress

Introduction. No previous population-based studies have used validated instruments to measure female sexual dysfunction (FSD) in Australian women across a broad age range.
Aim. To estimate prevalence and explore factors associated with the  components of FSD.
Main Outcome Measures. Sexual Function Questionnaire measured low sexual function. Female Sexual Distress Scale measured sexual distress.
Methods. Multivariate analysis of postal survey data from a random sample of 356 women aged 20–70 years.
Results. Low desire was more likely to occur in women in relationships for 20–29 years (odds ratio 3.7, 95% confidence intervals 1.1–12.8) and less likely in women reporting greater satisfaction with their partner as a lover (0.3, 0.1–0.9) or who placed greater importance on sex (0.1, 0.03–0.3). Low genital arousal was more likely among women who were perimenopausal (4.4, 1.2–15.7), postmenopausal (5.3, 1.6–17.7), or depressed (2.5, 1.1–5.3), and was less likely in women taking hormone therapy (0.2, 0.04–0.7), more educated (0.5, 0.3–0.96), in their 30s (0.2, 0.1–0.7) or 40s (0.2, 0.1–0.7), or placed greater importance on sex (0.2, 0.05–0.5). Low orgasmic function was less likely in women who were in their 30s (0.3, 0.1–0.8) or who placed greater importance on sex (0.3, 0.1–0.7). Sexual distress was positively associated with depression (3.1, 1.2–7.8) and was inversely associated with better communication of sexual needs (0.2, 0.05–0.5). Results were adjusted for other covariates including age, psychological, socioeconomic, physiological, and relationship factors.
Conclusions. Relationship factors were more important to low desire than age or menopause, whereas physiological and psychological factors were more important to low genital arousal and low orgasmic function than relationship factors. Sexual distress was associated with both psychological and relationship factors.

Modeling response rates in surveys of female sexual difficulty and dysfunction

INTRODUCTION: Studies that address sensitive topics, such as female sexual difficulty and dysfunction, often achieve poor response rates that can bias  results. Factors that affect response rates to studies in this area are not well characterized.
AIM: To model the response rate in studies investigating the prevalence of female sexual difficulty and dysfunction.
METHODS: Databases were searched for English-language, prevalence studies using the search terms: sexual difficulties/dysfunction, woman/women/female, prevalence, and cross-sectional. Studies that did not report response rates or were clinic-based were excluded. A multiple linear regression model was constructed.
MAIN OUTCOME MEASURES: Published response rates.
RESULTS: A total of 1,380 publications were identified, and 54 of these met our inclusion criteria. Our model explained 58% of the variance in response rates of studies investigating the prevalence of difficulty with desire, arousal, orgasm, or sexual pain (R(2) = 0.581, P = 0.027). This model was based on study design variables, study year, location, and the reported prevalence of each type of sexual difficulty. More recent studies (beta = -1.05, P = 0.037) and studies that only included women over 50 years of age (beta = -31.11, P = 0.007) had lower response rates. The use of face-to-face interviews was associated with a higher response rate (beta = 20.51, P = 0.036). Studies that did not include questions regarding desire difficulties achieved higher response rates than those that did include questions on desire difficulty (beta = 23.70, P = 0.034).
CONCLUSION: Response rates in prevalence studies addressing female sexual difficulty and dysfunction are frequently low and have decreased by an average of just over 1% per anum since the late 60s. Participation may improve by conducting interviews in person. Studies that investigate a broad range of ages may be less representative of older women, due to a poorer response in older age groups. Lower response rates in studies that investigate desire difficulty suggest that sexual desire is a particularly sensitive topic.

Relationship between hypoactive sexual desire disorder and aging

Objective: Explore the association between Hypoactive Sexual Desire Disorder (HSDD) and aging. The American Foundation of Urologic Disease and the American Psychiatric Association stipulate that HSDD is only diagnosed when both low sexual desire and sexually related personal distress are present.
Design : Community-based, cross-sectional study.
Setting : Europe (UK, Germany, France, Italy) and the USA.
Patient(s) Women aged 20-70 in sexual relationships participating in the Women’s International Study of Health and Sexuality (n=1998 Europe, n=1591 USA).
Intervention(s) : No interventions were administered.
Main Outcome Measures : Self-administered questionnaire that included two validated instruments: Profile of Female Sexual Function© measured sexual desire; Personal Distress Scale© measured sexual distress. Women with low desire and distress were considered to have HSDD.
Results : The proportion of European women with low desire increased from 11% amongst women aged 20-29 years to 53% amongst women aged 60-70 years. The proportion of American women with low desire displayed a trend towards an increase with age. In the 20-29 year age group 65% of European women and 67% of American women with low sexual desire were distressed by it. This decreased to 22% and 37%, respectively, in the 60-70 year age group. In Europe and the USA the prevalence of HSDD in the population did not change significantly with age (6-13% in Europe, 12-19% in the USA).
Conclusions: The proportion of women with low desire increased with age while the proportion of women distressed about their low desire decreased with age. Consequently, the prevalence of HSDD remained essentially constant with age. This may explain why no association between HSDD and age is often reported in the literature.

What is the "true" prevalence of female sexual dysfunctions and does the way we assess these conditions have an impact?

Introduction. A wide range of prevalence estimates of female sexual dysfunctions (FSD) have been reported.
Aim. Compare instruments used to assess FSD to determine if differences between instruments contribute to variation in reported prevalence.
Main Outcome Measures. Sexual Function Questionnaire combined with Female Sexual Distress Scale (SFQ-FSDS) was our gold standard, validated instrument for assessing FSD. Alternatives were SFQ alone and two sets of simple questions adapted from Laumann et al. 1994.
Methods. A postal survey was administered to a random sample of 356 Australian women aged 20 to 70 years.
Results. When assessed by SFQ-FSDS, prevalence estimates (95% confidence intervals) of hypoactive sexual desire disorder, sexual arousal disorder (lubrication), orgasmic disorder, and dyspareunia were 16% (12% to 20%), 7% (5% to 11%), 8% (6% to 12%), and 1% (0.5% to 3%), respectively. Prevalence estimates varied across alternative instruments for these disorders: 32% to 58%, 16% to 32%, 16% to 33%, and 3% to 23%, respectively. Compared with SFQ-FSDS alternative instruments produced higher estimates of desire, arousal and orgasm disorders and displayed a range of sensitivities (0.25 to 1.0), specificities (0.48 to 0.99), positive predictive values (0.01 to 0.56), and negative predictive values (0.95 to 1.0) across the disorders investigated. Kappa statistics comparing SFQ-FSDS and alternative instruments ranged from 0 to 0.71 but were predominantly 0.44 or less. Changing recall from previous month to 1 month or more in the previous year produced higher estimates for all disorders investigated. Including sexual distress produced lower estimates for desire, arousal, and orgasm disorders.
Conclusions. Prevalence estimates of FSD varied substantially across instruments. Relatively low positive predictive values and kappa statistics combined with a broad range of sensitivities and specificities indicated that different instruments identified different subgroups. Consequently, the instruments researchers choose when assessing FSD may affect prevalence estimates and risk factors they report.

The impact of study design on prevalence estimates of female sexual dysfunction

Introduction, objectives Despite increasing research, the true prevalence of Female Sexual Dysfunction (FSD) remains a contentious issue. Previous research suggests that aspects of study design affect the reported prevalence of FSD. We compare commonly used instruments for assessing FSD. Methods A random sample of 240 Australian women aged 20-70 participated in this population based, cross-sectional study. A questionnaire mailed to women across Australia included four instruments for assessing FSD. The Sexual Function Questionnaire combined with the Female Sexual Distress Scale (SFQ-FSDS) was employed as a standard, validated instrument. Alternative instruments were the SFQ alone and two modified versions of a set of questions originally developed by Laumann et al. Results When assessed by the SFQ-FSDS, prevalence estimates (and 95% confidence intervals) of Hypoactive Sexual Desire Disorder, Female Sexual Arousal Disorder (genital subtype), Female Orgasmic Disorder, and Dysparunia were 16%(11-20%), 8%(4-11%), 9%(6-13%), 2%(0.1-3%) respectively. The prevalence estimates of these same disorders obtained using alternative instruments were 32-55%, 17-35%, 17-33% and 3-25% respectively. The sensitivity of alternative instruments varied widely (0 to 1.0). Specificities ranged from 0.51 to 0.99. Positive predictive values ranged from 0 to 0.57. Negative predictive values were all above 0.90. Changing the time span for recalling sexual experiences in an instrument altered the prevalence estimates, sensitivity and specificity. 32% of women with low desire, 31% with low genital arousal, 36% with orgasm difficulty and 57% with sexual pain were sexually distressed. Conclusion Over a third of women who were classified as suffering FSD by alternative instruments did not have FSD when assessed by SFQ-FSDS. Alternative instruments produced substantially higher prevalence estimates of FSD and identified different groups of women. Consequently, the instruments researchers choose to assess FSD may affect both the prevalence estimates and risk factors they report.

Plumage reflectance and the objective assessment of avian sexual dichromatism

Assessment of color using human vision (or standards based thereon) is central to tests of many evolutionary hypotheses. Yet fundamental differences in color Vision between humans and other animals call this approach into question. Here we use techniques for objectively assessing color patterns that avoid reliance on species-specific (e.g., human) perception. Reflectance spectra are the invariant features that we expect the animal's color cognition to have evolved to extract. We performed multivariate analyses on principal components derived from >2,600 reflectance spectra (300-720 nm) sampled in a stratified random design from different body regions of male and female starlings in breeding plumage. Starlings possess spatially complex plumage patterns and extensive areas of iridescence. Our study revealed previously unnoticed sex differences in plumage coloration and the nature of iridescent and noniridescent sex differences. Sex differences occurred in some body regions bur not others, were more pronounced at some wavelengths (both ultraviolet and human visible), and involved differences in mean reflectance and spectral shape. Discriminant analysis based on principal components were sufficient to sex correctly 100% of our sample. If hidden sexual dichromatism is widespread, then it has important implications for classifications of animals as mono- or dimorphic and for taxonomic and conservation purposes.

Strategic concealment of sexual identity in an estrildid finch

One explanation for the evolution of sexual monomorphism is the sexual indistinguishability hypothesis, which argues that in group-living species individuals might benefit by concealing their sex to reduce sexual competition. We tested this hypothesis in long-tailed finches Poephila acuticauda. Males and females could not be reliably distinguished morphologically or by analysis of the reflectance spectra (300-700 nm) from the plumage and bill. Males seemed unable to distinguish the sex of an unfamiliar individual in the absence of behavioural cues; they were equally likely to court and copulate with unfamiliar males and females but rarely courted familiar males. Here we report the first experimental evidence that sexual monomorphism enables strategic concealment of sex. Males were more likely to reveal their sex when faced with a solitary unfamiliar individual than a group of unfamiliar individuals. When encountering an unfamiliar male that revealed his sex, subordinate males were more likely to conceal their sex than dominant males.

Environmental variation and the maintenance of polymorphism : the effect of ambient light spectrum on mating behaviour and sexual selection in guppies

The intensity of sexual selection is influenced by environmental conditions because these conditions influence signal propagation and the risks of the signal being exploited by predators and parasites. We explore the possibility that spatial or temporal heterogeneity in environmental signalling conditions (in this case light spectrum) may induce fluctuating sexual selection on male behaviour and ornamentation in guppies. We used shade cloth and filters to experimentally manipulate light spectrum, mimicking conditions found naturally: early morning/late afternoon light (SC treatment), midday forest shade (F89 filter treatment) and midday woodland shade (F55 filter treatment). Females were more responsive to male courtship and males were less likely to attempt sneak copulations under F55 light than the other two treatments. By contrast, male display rate was not influenced by treatment. Females tended to prefer the same males under SC and F55 light, but attractiveness in these treatments was unrelated to attractiveness under F89 light. There were similarities among treatments in the traits that females preferred: females preferred males with larger areas of orange in all three treatments. There were, however, also some differences, including preference for larger males under F89 light and for smaller males under the other treatments. Overall, the influence of ambient light spectrum on the relative importance of mate choice and male sneak copulation may have important implications for the mode and strength of sexual selection in different environments. The findings on attractiveness and preference functions, however, suggest that light spectrum only weakly affects the direction of sexual selection by female choice.

Fracturing the façade : exploring the impact of childhood sexual abuse

Examination of previous empirical literature illustrates how researchers have concentrated on documenting the impact of childhood sexual abuse (CSA) on the later psychological functioning of survivors, through comparisons with those who have not had such a history. Only more recently has there been a focus on assessing the relationship between aspects of the abuse and specific psychological difficulties. This thesis investigated the relationships between CSA characteristics and women’s later psychological adjustment. The role of attributions, coping methods, parenting competency and marital satisfaction were also investigated. Qualitative data on perception of benefit and general reflections of participants were used to explore participants’ self-esteem, locus of control, decisions relating to parenting, disclosure experiences, and attributions in relation to their abuse, including the search for meaning. Recruitment through newspapers and counselling services led to 118 women volunteering to complete a questionnaire evaluating the characteristics of their CSA and their current psychological adjustment. Of this group, 33 subsequently volunteered to participate in a telephone interview that explored in greater depth issues related to the long-term impact of their CSA. Both quantitative and qualitative analyses were conducted on the data. The women reported a high prevalence of dysfunction in their families of origin. Abuse had generally commenced by middle childhood, and lasted for a number of years and often involved a number of perpetrators. Perpetrators were most likely to be intrafamilial, with stepfathers being over-represented. Sexual activities generally involved physical contact, with participation often induced by the use of coercion. Participants demonstrated significant difficulties in psychological adjustment, but attributions regarding the abuse improved over time. Some concerns were expressed regarding parenting competency, and avoidant coping methods were favoured. In general, participants were satisfied with their current marital relationship. Significant associations were found between coping methods, attributional style, beliefs and various psychological adjustment measures. Participants, in general, demonstrated low self-esteem and displayed an external locus of control. As a consequence of their experience of CSA, many participants reported they had decided not to have children. For those who did have children, CSA was almost universally seen as having had an impact on their parenting. Disclosure of CSA was usually delayed for a number of years, with poor outcomes generally resulting from disclosure when it occurred. Women with current partners rated them as very caring and not controlling. Participants were generally still searching for meaning in their abuse, despite many having accepted it. Survivors outlined an extensive range of long-term effects of CSA, and nominated a number of strategies that would assist in reducing these effects. The results of the study indicated that there are a number of characteristics associated with CSA which signal a higher risk of difficulties in psychological adjustment. Concerns of survivors regarding parenting were confirmed according to those who undertook this role. Unfortunately, concerns expressed by survivors that disclosure of their CSA would have had negative consequences was usually the case when they did finally disclose. However, the accessing of social and family support appeared to have an important role in changing the attributions of survivors regarding their CSA. Furthermore, change of attributions in relation to abuse may provide the key to resilience in survivors against the negative impact of CSA on later psychological adjustment.

Women's cognitive and emotional processing during sexual arousal : the effects of erotic film and absorption

Sexual arousal is a complex and dynamic element of women’s sexuality. Accounts vary, however most multidimensional models highlight the cognitive, affective and physiological components of the female sexual arousal response. While literature examining the peripheral physiological changes that occur during female sexual arousal abounds, there has been a dearth of literature pertaining to the cognitive and affective components. Thus, while many authors have included cognitive and emotions as independent components of the female sexual arousal response, there has been little empirical research to validate this approach. The aim of the current thesis was to examine the cognitive and affective components of female sexual arousal in more depth, investigating the nature of the relationship between these components under various experimental conditions. In order to do so, two integrated studies were conducted, each highlighting the effects of either external or internal variables on women’s subjective sexual arousal, absorption, positive affect and negative affect. Study One was designed to evaluate women’s emotional and cognitive processing of two elements of erotic film – foreplay and erotic context. 60 women were asked to report their subjective sexual arousal, absorption, positive affect and negative affect in response to one of four erotic film excerpts. The erotic excerpts varied in accordance with the degree of foreplay (low vs. high) depicted and the context in which the sexual activities took place (novel vs. habitual context). Women in the study responded more favourably to the high foreplay erotic film excerpt, subsequently reporting higher degrees of subjective sexual arousal, absorption and positive affect. Women also responded favourably to the erotic excerpt filmed in a novel context, reporting greater subjective sexual arousal as a result. The environment in which the sexual encounters were filmed failed to have an effect however, on women’s absorption or their positive or negative affect. The results of Study One suggest that stimulus specific variables, such as the degree of foreplay depicted, have a significant influence on female cognitive and emotional processing of erotic film. The results also suggest that a relationship exists between absorption, subjective sexual arousal and positive affect, albeit a correlational one. Specifically, there was evidence of parallel processing during sexual arousal, as participant reported sexual arousal, absorption and positive affect all increased and decreased in unison. Based on the results it was suggested that future research attempt to experimentally manipulate one of these variables, to examine its direct effect on the remaining variable. Thus, Study Two aimed to examine the effects of absorption on women’s cognitive and emotional processing of erotica. Study Two manipulated absorption at two levels (high vs. low), examining the impact of these states on participants’ subsequent absorption, subjective sexual arousal and positive and negative affect. 62 women were asked to read one of two sets of test session instructions. The first, participant-oriented instruction set, instructed participants to immerse themselves in the erotic film excerpt, as if they were active participants in the sexual exchange. The second, spectator-oriented instruction set, directed participants to observe and evaluate the erotic film. These instructions were designed to elicit high and low degrees of absorption, respectively. The utility of this approach when manipulating female absorption, was demonstrated by self reported ratings of absorption, given at the conclusion of the film presentation. Participants were also asked to report their subjective sexual arousal and positive and negative affect at the conclusion of the erotic film presentation. The findings of this study suggest that the adoption of a participant-oriented (high absorption) perspective elicits more favourable responses from participants than a spectator-oriented (low absorption) perspective, with participants in the former experimental group reporting greater degrees of subjective sexual arousal and positive affect. Negative affect was equivalent across experimental conditions, with the participants reporting that they experienced little to no aversive feelings during either of the experimental conditions. The results suggest that the degree to which a women immerses and absorbs herself in a sexual stimulus has a significant impact in her subsequent cognitive and affective processing of that stimulus. More specifically, it appears that women respond more favourably when they are highly absorbed and immersed in a stimulus, reporting greater subjective sexual arousal and positive affect. Overall, the results of Studies One and Two highlight the dynamic and complex nature of female sexual arousal. It appears that women have definite cognitive and affective responses to sexual stimuli. The magnitude of these responses may be mediated by a number of factors however, including the intrinsic qualities of the stimulus and the degree to which the woman attends to the stimulus. Both these variables act to either enhance or inhibit the sexual arousal response. There results have important implications for current sexuality literature. While women’s cognitions and emotions in response to erotic film were generally highly correlated, in some instances they differed, warranting their inclusion as separate elements in models of female sexual arousal. Furthermore, it might be suggested that the inclusion of an additional variable – absorption – into current models of female sexual arousal would prove beneficial, aiding researchers to better understand and predict the arousal process. As such, recommendations are made for a revised model of female sexual arousal. In terms of future directions, the results of the present thesis have implications for the treatment of sexual dysfunctions, suggesting that clinicians need to understand the internal and external variables that might contribute to the aetiology and maintenance of their presenting problems.