Women's Sexual Function and Dysfunction. Irwin Goldstein MD

Psychologic assessment and selfreport questionnaires in women: subjective measures of female sexual dysfunction

Raymond C Rosen, Jennifer L Barsky

Introduction and overview

Despite the prevalence (see Chapters 2.1—2.3 of this book) and frequent distress (see Chapter 2.4) associated with sexual dysfunction in women, there are few standardized or evidence- based methods available to assess women’s sexual function (see Chapters 9.1—9.5). This is a significant concern for researchers and clinicians alike, for whom the lack of available measures has served as a significant barrier to clinical research and treatment of sexual problems in women. In contrast, sexual problems in men, such as erectile dysfunction, are routinely diagnosed and assessed by means of either physiologic methods (e.g., Rigiscan) or standardized and widely used self-report instruments (e.g., International Index of Erectile Function).1,2 Currently available techniques for measuring physiologic arousal in women, such as vaginal photoplethysmography or pelvic magnetic resonance imaging, have not proven to be sufficiently sensitive or reliable for diagnosis or assessment of clinical outcomes associated with treatment.3 Although vaginal photoplethysmography (see Chapter 10.1) and other laboratory methods (see Chapters 10.2-10.7) have provided valuable insights into the interplay of physiologic and psychologic processes in women’s sexual arousal, the clinical utility or “real-world” application of these methods is extremely limited. Instead, assessment of sexual function and dysfunction in women is based almost exclusively on self-report measures, including structured interviews, diary or event log measures, or, most commonly, self-report questionnaires. These latter measures are reviewed in detail in this chapter.

Prior to considering the psychometric properties and application of these measures, some key theoretic and conceptual points are worth noting. First, the definitions and classification of sexual dysfunction in women are undergoing rapid change and evolution.4,5 Major changes have been proposed in the categories of desire and arousal disorders in particular, which may necessitate development of new foci and methods of assessment (e.g., subjective sexual arousal) (see Chapter 9.1). Second, the linear sexual response cycle model, first proposed by Masters and Johnson6 and modified subsequently by Kaplan,7 has been strongly criticized in recent years for failing to emphasize the psychologic complexities of sexual desire in women, and the importance of subjective aspects of female sexual response. It is uncertain what effect these new models of sexual response will have on self-report measures in women. Third, the sensitivity of current self-report measures to treatment response has been difficult to assess in the absence of well-defined and effective treatments for women’s sexual dysfunction. Thus, while there is evidence for discriminant and convergent validity of various selfreport measures,8 the paucity of data supporting their sensitivity to treatment effects is a major omission to be addressed in future clinical trials.

Models of sexual response in women: the interplay of subjective and physiologic factors

The sexual response cycle model, developed originally by Masters and Johnson6 and modified subsequently by Kaplan7 and others, consists of a linear progression of sexual desire, arousal, and orgasm in both men and women. This influential model forms the basis of both the diagnostic classification system for sexual dysfunction in both genders, and the corresponding selfreport measures used to assess disturbances in each phase of the sexual response cycle. Despite its widespread adoption, criticism has been directed at the conceptual and clinical foundations of the traditional sexual response cycle model. Alternative formulations have recently been proposed, most notably the cyclical or interactive sexual response cycle model of Basson,9 in which sexual desire and arousal are conceptualized as interactive and mutually reinforcing aspects of sexual response. Sexual and emotional satisfaction are viewed as integral components of the process of sexual response in women. According to this model, the physiologic and subjective aspects of sexual response are described as separate, albeit integral components of sexual response. A new classification schema for sexual dysfunction in women has recently been proposed, in which separate categories of genital and subjective arousal disorder are described in detail.5 An obvious consequence of the revised sexual response cycle model and diagnostic classification schema has been to focus increasing attention on assessing subjective aspects of sexual response in women.

Assessment methods

Self-administered questionnaires

Although subjective sexual function can be assessed in several ways, the preferred and most widely used method is the self- administered questionnaire. Self-administered questionnaires have the advantages of assessing multiple components of sexual response, ease of administration and scoring, and ability to be translated and adapted for use in multinational settings. The principal limitation of self-administered questionnaires is that they do not directly assess physiologic aspects of sexual response; consequently, information about the genital aspects of sexual response is necessarily indirect and possibly less reliable than other responses. This may be especially true in women, as past research has frequently shown a marked discordance between subjective and physiologic aspects of female sexual response.10,11

At present, several self-administered questionnaires are in widespread use, including the Brief Index of Sexual Functioning for Women,12,13 the Female Sexual Function Index,14 and the Sexual Function Questionnaire.15 These self-administered questionnaires typically assess sexual functioning across a number of domains (e.g., sexual desire, arousal, orgasm, satisfaction) and measure average responses over a specified time period (e.g., 4 weeks). Scoring algorithms are provided for each of the sexual functioning domains and the entire questionnaire.

In selecting a self-administered questionnaire measure for use in a clinical trial, several criteria should be considered. Overall, self-administered questionnaires have been much more widely used in outpatient (at-home) treatment studies in both men and women. These measures are also most suitable when used in a prospective study design, in which each patient is assessed before and after a treatment intervention in order to assess changes associated with treatment.

Event logs and daily diaries

A variety of event logs and daily diaries have been used in clinical trials of male and female sexual dysfunction. Diaries or event logs are designed to be completed after each episode of sexual activity and assess sexual functioning and satisfaction during each sexual episode. There are currently no standardized or validated sexual event logs for women, although several instruments have been proposed or are currently in development. Results from the sexual event log are typically regarded as primary or secondary endpoints from a regulatory perspective. According to the US Food and Drug Administration Guidance Document of Female Sexual Dysfunction, event log measures of satisfying sexual events should be used as primary endpoints in clinical trials of female sexual dysfunction.

Structured interviews

Assessments that are directly administered by the researcher, such as the Derogatis Interview for Sexual Functioning,16 can provide more detailed and specific information about sexual functioning. Although the breadth of information that can be obtained from an interview is potentially valuable, structured interviews are more time-consuming to administer than self- administered questionnaires and are potentially more burdensome for both patients and investigators. To date, this assessment strategy has seldom been used in clinical trials.

Criteria for assessment instruments

The two most fundamental and desirable characteristics for measures of sexual function in women are reliability and validity. Reliability refers to the consistency or replicability of results, with reliability coefficients serving as quantitative indicators of measurement consistency. Validity reflects the degree to which an instrument measures what it purports to measure. Unlike reliability, which is established through a specific, rigorously prescribed series of statistical exercises, the validation of a measuring instrument is ongoing and iterative in nature.

The two essential indicators of validity for measures of sexual function are discriminant validity and sensitivity to therapeutically induced change. The former refers to an instrument’s capacity to discriminate sexually dysfunctional individuals from persons without sexual problems (sensitivity and specificity in epidemiologic terms, or discriminant validity in psychometric terms), while the latter criterion refers to an instrument’s sensitivity to clinical change associated with treatment (longitudinal validity in psychometric terms). These are both essential criteria of measures designed to serve as diagnostic and/or treatment efficacy measures in either clinical or research settings. The reliability and validity of the most widely used self-administered questionnaire measures for female sexual function are described below.

Specific self-administered questionnaires for assessment of female sexual function

Self-report measures, such as questionnaires and daily diaries, are greatly preferred to other assessment methods for large-scale, multicenter trials. Simple self-report scales, such as the International Index of Erectile Function, have been shown to be highly sensitive and reliable indicators of treatment efficacy in men,1,2 and efforts have been made to achieve a similar degree of precision and reliability with self-administered questionnaires for female sexual function.

Brief Index of Sexual Functioning for Women

Description

This is a 22-item, multidimensional, self-report measure for women that assesses sexual function in seven dimensions: sexual thoughts/desires, arousal, frequency of activity, receptivity/ initiation, pleasure/orgasm, relationship satisfaction, and sexual problems.12 In addition to these domain scores, this measure yields an overall composite score. It takes about 15-20 min to complete and is intended for use among both clinical and nonclinical samples of heterosexual and homosexual women.

Psychometric evaluation

The Brief Index of Sexual Functioning for Women was validated in a normative sample of 225 healthy women aged 22-55 years, 187 of whom had sexual partners, and in a clinical sample of 104 surgically menopausal women of the same age with impaired sexual function.13 This measure was able to discriminate between normal women with and without sexual partners and between the normative and clinical sample groups on six out of seven dimensions and overall composite scores. In particular, the surgically menopausal women scored the lowest on the domains pertaining to sexual desire, arousal, and frequency of activity. The internal consistency of this measure ranged from 0.39 for the arousal domain to 0.72 for the dimensions of sexual desire and orgasm. Test-retest reliability of the original three- factor scores ranged from 0.68 to 0.78 at baseline and a 1-month interval. A high concurrent validity was found through comparison with relevant scales of the Derogatis Interview for Sexual Function.16 Recently, this measure was found to be sensitive to effects of testosterone therapy in a sample of women with bilateral oophoectomy.17

Comments

The Brief Index of Sexual Functioning for Women was one of the first self-administered questionnaires of female sexual function and satisfaction to provide a detailed assessment of broad areas of function. One of the weaknesses of this measure is a relatively low internal consistency for three of the seven domains. Some of these inconsistencies may result from the fact that the design of this measure was based largely on the male version, the Brief Sexual Function Questionnaire. Thus, some of the items in this measure may not be as specific to female sexual function as more recently developed instruments.

Sexual Function Questionnaire (SFQ)

Description

The Sexual Function Questionnaire is a brief, multidimensional, patient-centered measure of women’s sexual functioning that was developed for use in clinical trials.15 Items were generated through semistructured interviews with 82 women aged 19-65 years old from seven countries (UK, USA, Australia, the Netherlands, Denmark, France, and Italy) and included women with and without female sexual dysfunction. Phrases used by these women to describe experiences of female sexual dysfunction were incorporated into the measure. Through factor analysis, seven domains of women’s sexual functioning were identified: desire, physical arousal-sensation, physical arousal-lubrication, enjoyment, orgasm, pain, and partner relationship. The Sexual Function Questionnaire can be used in three forms: a 34-item version that consists of the seven domains mentioned plus additional items and the arousal-cognitive domain, a 26-item version that consists of seven domains, and a short-item version (Abbreviated Sexual Function Questionnaire) that includes four of the seven domains (desire, arousal-sensation, arousal-lubrication, and orgasm). This measure takes 10-15 min to complete and is intended for women in a sexual relationship or who have participated in sexual activity within the previous month.

Psychometric evaluation

This measure was initially validated in a sample of 982 women aged 19-65 years. The sample included women both with and without a clinical diagnosis of female sexual dysfunction.15

Internal consistency of the domains was reasonably high, with Cronbach’s alphas ranging from 0.65 to 0.91. Test-retest reliability was conducted over a 4-week period, and coefficients ranged from 0.42 to 0.78 for individual items. Discriminant validity for this measure was high; women with sexual dysfunction scored significantly lower than women without dysfunction on all seven domains at baseline. In addition, all seven domains of the Sexual Function Questionnaire were able to discriminate between women who reported improvement in their sexual functioning at the end of the study (responders) and those who reported no improvement (nonresponders). Construct validity was found to be acceptable through correlations between the Sexual Function Questionnaire domains and relevant domains of the Derogatis Interview for Sexual Functioning,16 the Fugl-Meyer Life Satisfaction Checklist,18 and the Hospital Anxiety and Depression Scale.19

Female Sexual Function Index (FSFI)

Description

The Female Sexual Function Index is a 19-item, multidimensional, self-report instrument used to assess key domains of female sexual function.14 This measure was initially designed to assess female sexual arousal disorder. Responses are based on sexual activity within the past 4 weeks. Six domains were identified through a factor analysis: desire, subjective arousal, lubrication, orgasm, satisfaction, and pain. A full-scale score that represents overall sexual function may be calculated from the domain scores. This measure takes about 15 min to complete and is intended for use in clinical trial and community populations and among both heterosexual and homosexual women.

Psychometric evaluation

This measure was initially validated in a sample of 128 heterosexual women with female sexual arousal disorder and 131 age- matched heterosexual healthy women aged 21-69 years.14 Internal consistency was high, as all domains had Cronbach’s alphas above 0.82. Test-retest reliability was high over a 2-4- week period, ranging from 0.79 to 0.86 for the domains, and 0.88 for the full-scale score. Significantly lower scores were reported by women with female sexual arousal disorder in all domains and overall, demonstrating discriminant validity. The largest differences between the groups were in the domains of lubrication and arousal. A second study showed the Female Sexual Function Index subscales and full-scale score to discriminate reliably between women without sexual dysfunction and women with female orgasmic disorder.20 Recently, discriminant validity was further established in samples of women with hypoactive sexual desire disorder, sexual pain disorders, and multiple sexual dysfunctions.21

Divergent validity was established through comparison with the Locke-Wallace Marital Adjustment Test.22 In the first study, correlations between the relevant domains on these scales were of modest size, ranging from 0.19 for the desire subscale, to 0.57 for the satisfaction with partner subscale, in the full sample of both female sexual arousal disorder patients and controls. The full-scale score yielded a correlation of 0.41 with the Locke-Wallace Marital Adjustment Test.14 These expected levels of association between the theoretically related constructs of sexual function and marital adjustment support the construct validity of the Female Sexual Function Index. The second validation supported these findings regarding the divergent validity of the Female Sexual Function Index with the same comparison scale.

Comments

The Female Sexual Function Index is easy to administer and score, and is currently being used in a number of clinical trials. This measure has been extensively studied and has generally been shown to perform extremely well in psychometric analyses. However, this scale has not yet been evaluated for its specificity to treatment-related change.

Menopausal Sexual Interest Questionnaire (MSIQ)

Description

This measure is a very brief (10-item), unidimensional instrument that measures sexual function in postmenopausal women.23 Although the Menopausal Sexual Interest Questionnaire includes some items addressing other aspects of sexual response, this measure primarily focuses on sexual desire, given the prevalence of hypoactive sexual desire disorder in postmenopausal women. Initial item selection was performed by a panel of experts in the field of sexual dysfunction, and pilot testing was then conducted with women attending menopause management groups at 18 sites across the USA. Three domains were identified through factor analysis: desire, responsiveness, and satisfaction; however, the constructs assessed by these domains seem to overlap considerably. A full-scale score is also available. This measure takes approximately 5 min to complete and is intended for use by postmenopausal women.

Psychometric evaluation

This measure was validated in a sample of 111 postmenopausal women without hypoactive sexual desire disorder and an age- matched sample of 221 women with a clinical diagnosis of hypoactive sexual desire disorder who were participating in a treatment trial.23 Internal consistency of the three domains was very high. Cronbach’s alphas for the items within each domain were 0.87 and higher. One-month test-retest reliability was acceptable, with Pearson coefficients ranging from 0.52 to 0.76 for individual items and 0.79 for the overall scale. Each Menopausal Sexual Interest Questionnaire domain and the full score were able to discriminate between women with and without hypoactive sexual desire disorder. Convergent validity was established through comparison with the thought/desire domain of the Brief Index of Sexual Functioning for Women (BISF-W)12 and found to be high, yielding a correlation coefficient of 0.82 for the desire domain of the Menopausal Sexual Interest Questionnaire, and 0.81 for the full-scale score. Divergent validity was established by comparing the full-scale score of the Menopausal Sexual Interest Questionnaire with the anxiety and depression domains of the Kellner Symptom Questionnaire (KSQ)24 and the sexual domain of the Menopause Specific Quality of Life Questionnaire (MENQOL).25 The correlations were -0.002, -0.14, and -0.42, respectively. These findings support the construct validity of the Menopausal Sexual Interest Questionnaire. The Menopausal Sexual Interest Questionnaire also demonstrated sensitivity to therapeutic effects in a clinical trial, showing increases in scores pre- to post-treatment among self-identified responders, but not in nonresponders.23

Profile of Female Sexual Function (PFSF)

Description

The Profile of Female Sexual Function is a somewhat lengthy (37-item), patient-centered, multidimensional measure that targets the assessment of low sexual desire and associated symptoms in postmenopausal women suffering from hypoactive sexual desire disorder.26 This measure was developed and tested for language coherence through interviews with surgically and naturally menopausal women from the USA, Germany, the UK, Italy, France, the Netherlands, Canada, and Australia. This scale consists of six domains: sexual pleasure, sexual desire, responsiveness, arousal, orgasm, sexual self-image, and sexual concerns. This measure is intended for use in clinical trial populations.

Psychometric evaluation

This scale was validated in a sample of 325 oophorectomized women with hypoactive sexual desire disorder and an age- matched sample of 255 premenopausal control women in the USA, Canada, Europe, and Australia.26 Cronbach’s alpha coefficients, assessing internal consistency within each of the domains, ranged from 0.79 to 0.96 in the low-libido group and 0.50 to 0.96 in the control group. Intraclass correlation coefficients reflecting 2-week test-retest reliability ranged from 0.52 to 0.90 in the low-libido group and from 0.66 to 0.92 in the control group. A second validation study including naturally menopausal women27 found similar results to support the internal consistency (Cronbach’s alpha = 0.74-0.95), and 4- week test-retest reliability (intraclass correlation coefficients = 0.57-0.91) of the six domains. Domain intercorrelations ranged from 0.18 to 0.66, with a median of 0.50, indicating relatively little redundancy. The Profile of Female Sexual Function and its individual domains discriminated between oophorectomized women with low libido and age-matched controls across geographic regions.26 Discriminant validity was further supported in samples of both surgically and naturally menopausal women with hypoactive sexual desire disorder.27 The sensitivity, specificity, and positive predictive value of this measure were calculated according to each domain, and ranged from 0.67 to 0.94, 0.86 to 0.95, and 0.86 to 0.94, respectively. Convergent validity was established through statistically significant correlations with relevant domains of the Derogatis Sexual Functioning Inventory (DSFI-SR).

Comments

The Profile of Female Sexual Function has demonstrated excellent psychometric properties and is notable for its international patient-based development and validation. However, the Profile of Female Sexual Function is not yet readily available for general use in clinical trials.

Female Sexual Distress Scale (FSDS)

Description

This is a 12-item, unidimensional scale measuring sexual distress in women.28 The Female Sexual Distress Scale was developed to reflect recent classifications of female sexual dysfunction that take into account sexually related personal distress as an important factor in the diagnosis of female sexual dysfunction.4 Prior to this measure, no methods of evaluating sexually related personal distress were available. This measure takes about 5 min to complete and is intended for use with women presenting for an evaluation concerning sexual dysfunction.

Psychometric evaluation

The reliability of the Female Sexual Distress Scale was established over the course of three separate clinical trials, consisting of a control group and several groups of women with various sexual dysfunctions.28 Through a principal components analysis, items that did not load substantially on a principal component of the original 20 items were eliminated, leaving a 12-item version. Internal consistency of the items in this measure was very high, with Cronbach’s alphas ranging from 0.86 to 0.97. Test-retest reliability coefficients ranged from 0.80 to 0.92. Discriminant validity was established through comparisons between both naturally and surgically menopausal women and healthy age-matched controls. In this trial, the Female Sexual Distress Scale demonstrated both sensitivity and specificity of 0.93, and a positive predictive value of approximately 0.90. These measures were highest when using a cutoff score of ^ 15 on this scale. Findings indicated that this measure was also highly sensitive to treatment-induced change from baseline to termination of treatment. Construct validity was established through comparisons between the Female Sexual Distress Scale and other measures of psychologic distress, which yielded correlations of moderate magnitude in the expected direction.

Comments

The Female Sexual Distress Scale offers potential for specifically targeting women’s sexually related personal distress, a relatively new concept and a key component in the diagnosis of female sexual dysfunction. The Female Sexual Distress Scale is recommended as an instrument to complement, rather than replace, other multidimensional measures in the evaluation of female sexual dysfunction.

Golombok Rust Inventory of Sexual Satisfaction

Description

The Golombok Rust Inventory of Sexual Satisfaction is a 56- item (28 items for women and 28 items for men), self-report measure designed to assess the presence and severity of sexual problems among sexually active individuals and heterosexual couples.29 Originally developed for use with sex therapy clients, it is intended to be used to assess each partner’s individual sexual functioning as well as that of the overall relationship. When assessing individuals, the men’s and women’s items may be presented as two separate forms. This measure consists of 12 four-item domain scores: five for women, five for men, and two scores in common for both. Men’s domains consist of the following: premature ejaculation, impotence, avoidance, nonsensuality, and dissatisfaction. The equivalent domains for women are anorgasmia, vaginismus, avoidance, nonsensuality, and dissatisfaction. The two domains in common to both men and women are frequency of sexual contact and noncommunication. An overall composite score is calculated to summarize the quality of sexual and relationship functioning in the couple. This measure takes approximately 15 min to administer and is targeted for use with heterosexual sex therapy clients.

Psychometric evaluation

The Golombok Rust Inventory of Sexual Satisfaction was originally developed with a standardized sample of 44 heterosexual couples (88 individuals) seeking marital or sex therapy.29,30 The split half reliability was 0.94 and 0.87 for the main female and male scales, respectively. Internal consistencies for the domain subscales ranged from 0.61 to 0.83, with an average of 0.74. Test-retest reliability coefficients, assessed using pre- and post-treatment scores, were 0.76 and 0.65 for the male and female overall scores, respectively, and ranged from 0.47 to 0.84 for the domain subscales. However, because of improvements due to therapy, these reliability coefficients are likely to be underestimates.

The overall female and male scores were able to discriminate subjects with a clinical diagnosis of a sexual problem from a control group consisting of general medical patients. In addition, specific dysfunctional groups differed from the control subjects on the relevant subscales. Therapists’ ratings of problem severity correlated with both the female and male scale scores (correlations of 0.56 and 0.53, respectively). Therapists’ ratings of improvement after five sex therapy sessions also correlated with change scores in the female and male scale score (correlations of 0.54 and 0.43, respectively).30

More recently, the Golombok Rust Inventory of Sexual Satisfaction has been translated into Dutch and tested for its psychometric properties in a Dutch population.31,32 In the first study, this measure was tested in 305 heterosexual couples with a sexual problem and 68 student couples.31 This study provided further support for the 12-factor structure of the Golombok Rust Inventory of Sexual Satisfaction, and lent additional support for the reliability and validity of the measure. Internal consistencies, as assessed by Cronbach’s alpha, ranged from 0.55 to 0.85 for the domain subscales, and 0.87 for the overall scale. A high degree of intercorrelation was found among the subscales, suggesting that the measure might assess overlapping constructs. Test-retest reliability coefficients in the nonclinical couples ranged from 0.63 to 0.94 over a 2-week period. The Golombok Rust Inventory of Sexual Satisfaction was found to predict the presence of sexual dysfunction in individual men in a urologic clinic.32

Discussion and conclusion

Although physiologic measures such as vaginal photoplethysmography have contributed to our understanding of basic mechanisms in female sexual response, these are of limited benefit in diagnostic assessment or clinical studies of female sexual dysfunction. To provide a multidimensional assessment of sexual function, a number of self-administered questionnaires have been developed in recent years. Several of these measures have demonstrated adequate psychometric properties, including test-retest reliability, internal consistency, and discriminant validity. Self-administered questionnaires are widely used at present to assess sexual function in women.

Daily diary and sexual event log measures have also been developed for use in clinical trials of female sexual dysfunction. These are typically used in conjunction with self-administered questionnaires measures, and have been recommended for use as endpoints in clinical trials by the US Food and Drug Administration. However, daily diary measures have not been adequately validated and lack the potential for multidimensional assessment.

Although self-administered questionnaires offer a valid and user-friendly means of assessing sexual function, several limitations should be noted. First, these measures provide information only on current level of sexual function and cannot substitute for a detailed sexual, psychologic, or medical history. Furthermore, the current questionnaires do not provide information on specific background or etiology, or the role of comorbid medical or psychiatric conditions. Additionally, some patients may experience discomfort or embarrassment while completing questionnaires or symptom scales, or may have difficulty with comprehension. Steps should always be taken to ensure privacy and confidentiality and to assist the patient with comprehension when indicated. Finally, questionnaires or symptom scales should not be used as an alternative to or substitute for direct inquiry or face-to-face clinical interaction with the clinician.

References

1. Rosen R, Riley A, Wagner G et al. The International Index of

Erectile Function (IIEF): a multi-dimensional scale for assessment

of male erectile dysfunction (MED). Urology 1997; 49: 822-30.

2. Rosen R, Cappelleri J, Gendrano N. The International Index of Erectile Function (IIEF): a state-of-the-science review. Int J Impot Res 2002; 4: 1-17.

3. Rosen R. Measurement of male and female sexual dysfunction. Curr Psychiatry Rep 2001; 3: 182-7.

4. Basson R, Berman J, Burnett Aetal. Report of the international consensus development conference on female sexual dysfunction: definitions and classifications. J Urol 2000; 163: 888-93.

5. Basson R, Leiblum S, Brotto Letal. Defintions of women’s sexual function reconsidered: advocating expansion and revision. J Psychosom Obstet Gynaecol 2004; 24: 221-9.

6. Masters WH, Johnson VE. Human Sexual Inadequacy. Boston: Little, Brown, 1970.

7. Kaplan HS. The New Sex Therapy. New York: Brunner Mazel, 1974.

8. Rosen RC. Assessment of female sexual dysfunction: review of validated methods. FertilSteril 2002; 77: S89-93.

9. Basson R. The female sexual response: a different model. J Sex Marital Ther 2000; 26: 51-65.

10. Rosen RC, Beck JG. Patterns of Sexual Arousal: Psychophysiological Processes and Clinical Applications. New York: Guilford Press, 1988.

11. Laan E, Everaerd W, van der Velde Jetal. Determinants of subjective experience of sexual arousal in women: feedback from genital arousal and erotic stimulus content. Psychophysiology 1995; 32: 444-51.

12. Taylor JF, Rosen RC, Leiblum SR. Self-report assessment of female sexual function: psychometric evaluation of the Brief Index of Sexual Function for Women. ArchS&BehOV 1994; 23: 627-43.

13. Mazer NA, Leiblum SR, Rosen RC. The Brief Index of Sexual Functioning for Women (BISF-W): a new scoring algorithm and comparison of normative and surgically menopausal populations. Menopause 2000; 7: 350-63.

14. Rosen R, Brown C, Heiman Jetal. The Female Sexual Function Index (FSFI): a multidimensional self-report instrument for the assessment of female sexual function. J Sex Marital Ther 2000; 26: 191-208.

15. Quirk FH, Heiman JR, Rosen RC et al. Development of a sexual function questionnaire for clinical trials of female sexual dysfunction. jw^men-HeateLGerndBasedMei 2002; 11: 277-89.

16. Derogatis LR. The Derogatis Interview for Sexual Functioning (DISF/DISF-SR): an introductory report. J Sex Marital Ther 1997; 23: 291-304.

17. Shifren JL, Braunstein GD, Simon JA et al. Transdermal testosterone treatment in women with impaired sexual function after oophorectomy. NEngUMedt 2000; 343: 682-8.

18. Fugl-Meyer AR, Lodnert G, Branholm IB et al. On life satisfaction in male erectile dysfunction. IntJJmpotRes 1997; 9: 141-8.

19. Zigmond, AS, Snaith RP. The Hospital Anxiety and Depression Scale. AcaPyckarSan 1983; 67: 361-70.

20. Meston CM. Validation of the Female Sexual Function Index (FSFI) in women with female orgasmic disorder and in women with hypo- active sexual desire disorder.

21. Wiegel M, Meston C, Rosen RC. The Female Sexual Function Index (FSFI): cross-validation and development of clinical cutoff scores. J Sex Marital Ther 2005; 31: 1-20.

22. Locke H, Wallace K. Short marital adjustment and prediction tests: their reliability and validity. Marriage Fam Living 1959; 2: 251-5.

23. Rosen RC, Lobo RA, Block BA et al. Menopausal Sexual Interest Questionnaire (MSIQ): a unidimensional scale for the assessment of sexual interest in postmenopausal women. J Sex Marital Ther 2004; 30: 235-50.

24. Kellner R, Sheffield BF. A self-rating scale of distress. Psychol Med 1973; 3: 88-100.

25. Hilditch JR, Lewis J, Peter Aetal. A menopause-specific quality of life questionnaire: development and psychometric properties. Maturitas 1996; 24: 161-75.

26. McHorney CA, Rust J, Golombok Setal. Profile of Female Sexual Function: a patient-based, international, psychometric instrument for the assessment of hypoactive sexual desire in oophorectomized women. Menopause 2004; 11: 474-83.

27. Derogatis L, Rust J, Golombok Setal. Validation of the Profile of Female Sexual Function (PFSF) in surgically and naturally menopausal women. J Sex Marital Ther 2004; 30: 25-36.

28. Derogatis LR, Rosen R, Leiblum Setal. The Female Sexual Distress Scale (FSDS): initial validation of a standardized scale for assessment of sexually related personal distress in women. J Sex Marital Ther 2002; 28: 317-30.

29. Rust J, Golombok S. The Golombok Rust Inventory of Sexual Satisfaction. 1985; 24: 63-4.

30. Rust J, Golombok S. The GRISS: a psychometric instrument for the assessment of sexual dysfunction. Arch Sex Behav 1986; 15: 157-65.

31. Ter Kuile MM, van Lankveld JJDM, Kalkhoven P et al. The Golombok Rust Inventory of Sexual Satisfaction (GRISS): psychometric properties within a Dutch population. J Sex Marital Ther 1999; 25: 59-71.

32. Van Lankveld JJDM, van Koeveringe GA. Predictive validity of the Golombok Rust Inventory of Sexual Satisfaction (GRISS) for the presence of sexual dysfunctions within a Dutch urological population. Int J Impot Res 2003; 15: 110-16.