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The 6-item Female Sexual Function Index (FSFI-6): factor structure, reliability, and demographic correlates among infertile women in Iran

Middle East Fertility Society Journal volume 24, Article number: 7 (2020) Cite this article

Abstract

Background

The 6-item Female Sexual Function Index (FSFI) is a short form of the original 19-item FSFI that measures sexual function in women. The aim of this study was to examine the factor structure and reliability of the FSFI-6 and to determine the demographic correlates of sexual dysfunction among infertile women in Iran.

Results

In total, 250 infertile women participated in this study. The mean total FSFI-6 score was 20.71 ± 5.09. Internal consistency of the FSFI-6 was high (Cronbach’s alpha = 0.856). All inter-item correlations and item-total correlations were in acceptable range. The results of confirmatory factor analysis provided support for a unidimensional model of the FSFI-6. Among demographic and infertility variables, higher women’s age, low education, unwanted marriage, short infertility duration, and low frequency of intercourse were associated with sexual dysfunction.

Conclusions

The FSFI-6 demonstrated sound reliability and validity in this study, supporting its continued use for measuring sexual disfunction among infertile women. Its brevity and comprehensiveness allow a quick assessment both in clinical and research settings.

Background

Infertility is defined as “the failure to establish a clinical pregnancy after 12 months of regular, unprotected sexual intercourse or due to an impairment of a person’s capacity to reproduce either as an individual or with his/her partner.” [1] and affects 9% of reproductive-age couples globally [2]. It is a worldwide health problem that is associated with adverse psychological and social consequences [3,4,5,6,7]. Researchers have shown that negative feelings, such as depression, stress, and anxiety, are often mental disorders after experiencing infertility [4, 8, 9]. As most couples consider childbirth as one of the most significant outcomes of sexual intercourse, infertile couples are more prone to experience psychological and emotional stress [10]. Infertility profoundly impacts the sexual enjoyment of a couple about scheduling programs for childbirth and fertility interventions [11, 12]. It has been shown that infertile couples have significantly more sexual issues than fertile couples [13]. The belief of sexual orientation is considerably affected by infertility-related pressure and depression and the region where infertility has the most adverse effect [14, 15].

Sexual behavior is a function of physiologic, anatomic, and psychosocial characteristics of a person [16]. Female sexual dysfunction has been introduced as disorders of sexual functioning, desire, and pain, which is followed by adverse consequences such as negative psychological outcomes [17]. Sexual function is a major element of women’s quality of life, which affects several dimensions of peri- and post-menopausal characteristics [18]. Previous studies have shown that on average, 64% of women suffer from desire difficulty, 35% of orgasm difficulty, 31% have complications with arousal conditions, and 26% with sexual pain [19]. Based on a systematic review of literature conducted in Iranian infertile women, the overall prevalence of female sexual dysfunction was 64.3% [20]. It has been argued that female sexual function is associated with age, body physics, hormonal condition, neurologic and vascular processes, and psychological health items [21].

A variety of instruments have been developed to measure female sexual function. Among these instruments, the 19-item Female Sexual Function Index (FSFI-19) is one of the main instruments for assessing female sexual function [18]. The FSFI-19 is a self-reported instrument, consisting of 6 separate domains of female sexual function, namely desire, arousal, lubrication, orgasm, satisfaction, and pain. This scale has been validated in many languages and widely used in clinical and research settings [22]. Despite being frequently used, psychometrically sound, and clinically interpretable, the FSFI-19 may be too long for use in studies with multiple outcome measures, especially when measuring sexual dysfunction is not a primary aim of a study. Because of this reason, recently, Isidori et al. developed a shorter version of the scale (i.e., FSFI-6) using receiver operating curves [18, 23]. The FSFI-6 is a brief and easy to use measure containing 6 of the original 19 items. This scale is useful for settings with a limited time frame (e.g., survey research).

The FSFI-6 has been validated in Italy, the USA, Brazil, Korea, Portugal, and Ecuador, mainly in the general population [18, 23,24,25,26,27]; however, they have not been validated in infertile women. Hence, this study aims to evaluate the validity and reliability of the FSFI-6 among a sample of women with infertility. A secondary aim was to determine the demographic correlates of sexual dysfunction among infertile women in Iran.

Methods

Participants and study design

The sample of this cross-sectional study consisted of infertile women referring to infertility treatment center of Royan Institute, Tehran, Iran. The data were collected between January and April 2017. The sample size was determined using the rule of thumb recommended by Guilford [28] and Cattell [29] for factor analysis studies. They offered researchers to obtain samples of 200 (or 250) subjects whenever possible. To be eligible for this study, subjects had to fulfill the following criteria: (1) women with infertility problem, (2) age between 18 and 45 years, and (3) ability to read and write in Persian. Participants were asked to complete the questionnaire privately and return it. A total of 250 infertile women agreed to take part and fill out the questionnaire completely.

Questionnaires

Demographic variables

Participants provided demographic/infertility information including age, education, husband’s age, husband’s education, occupation, type of marriage, body mass index (BMI), cause of infertility, infertility duration, frequency of intercourse per month, frequency of masturbation per month, and having private room, life in home with other family members or people.

The 6-item Female Sexual Function Index (FSFI-6)

The FSFI-6 is a 6-item, brief, and self-administered instrument derived from the original 19-item FSFI that measures female sexual function [23]. It comprises six domains: desire, arousal, lubrication, orgasm, satisfaction, and pain. Desire and satisfaction items are rated on a 5-point Likert scale, ranging from 1 to 5, and the other items are rated on a 6-point Likert scale, ranging from 0 to 5. Total scores range from 2 to 30, with lower scores indicating worse sexual functioning.

Statistical analysis

The factor structure of the FSFI-6 was examined with confirmatory factor analysis (CFA) using maximum likelihood estimation. Overall model fit was examined using multiple fit criteria, as suggested in the literature. Specifically, six goodness-of-fit indices were used, including chi-square/degree of freedom (χ2/df), comparative fit index (CFI), normalized fit index (NFI), incremental fit index (IFI), root mean square error of approximation (RMSEA), and standardized root mean square residual (SRMR). Values of χ2/df < 3, CFI, NFI, and IFI > 0.95, and RMSEA and SRMR < 0.08 are indicative of a good fit with the data [30,31,32,33]. To evaluate the internal consistency of the FSFI-6, Cronbach’s alpha, inter-item correlation, and corrected-item total correlation were calculated. Cronbach’s alpha value of 0.7 or greater indicates that the internal consistency is satisfactory [34]. Inter-item correlations examine the extent to which scores on one item are related to scores on all other items in a scale. The corrected item-total correlation is the correlation between each item and the total scale score based on the other items. Smaller values (i.e., less than 0.3) indicate that the given item is not well correlated with the others [35]. To examine the relationship of female sexual function (i.e., FSFI-6 scores) with demographic/infertility characteristics, stepwise backward regression analysis was done. Goodness of fit of the regression model was evaluated using the coefficient of determination (R2), which is the proportion of variation in the dependent variable explained by the regression model. Data analyses were carried out using SPSS for Windows, version 16.0 (SPSS Inc., Chicago, IL, USA) and LISREL 8.80 (Scientific Software International, Inc., Lincolnwood, IL, USA).

Results

Participant characteristics

Table 1 outlines the demographic characteristics of infertile women. The mean age of the participants was 29.74 ± 5.29 years. The majority of participants were unemployed (78.8%), had a private room at home (88.8%), and did not live with others (87.2%). The mean BMI was 25.68 ± 3.74 kg/m2.

Table 1 Demographic/fertility characteristics of the infertile women (n = 250)
Full size table

Descriptive statistics and internal consistency of the FSFI-6

The descriptive statistics and internal consistency of the FSFI-6 are displayed in Table 2. The mean FSFI-6 total score was 20.71 ± 5.09. The FSFI-6 showed high internal consistency with Cronbach’s alpha coefficient of 0.856. As seen in Table 2, Cronbach’s alpha did not considerably increase as a consequence of an item deletion. The corrected item-total correlations and the inter-item correlations ranged 0.423–0.799 and 0.216–0.738, respectively.

Table 2 Item wording and descriptive statistics and internal consistency of the FSFI-6
Full size table

Factor structure of the FSFI-6

To examine the factor structure of the FSFI-6, the CFA was carried out. The result of CFA confirmed the unidimensional factor structure of the FSFI-6 (χ2/df = 2.96; CFI = 0.98; NFI = 0.97; IFI = 0.98; RMSEA = 0.089 and SRMR = 0.035). As can be seen in Fig. 1, all factor loadings were significant and greater than 0.50, except for item 1.

Fig. 1
figure1

The unidimensional factor model of FSFI-6 in a sample of infertile women

Full size image

Demographic correlates of the FSFI-6 scores

Stepwise backward regression analysis was used to investigate the relationships between FSFI-6 scores and demographic/infertility characteristics. According to the results (see Table 3), higher women’s age (b = − 0.206, P = 0.004), low education (b = 0.718, P = 0.012), unwanted marriage (b = − 4.765, P = 0.008), short infertility duration (b = 0.200, P = 0.037), and low frequency of intercourse (b = 0.250, P < 0.001) were associated with sexual dysfunction. The model R2 when demographics and infertility variables were in the model was equal to 0.12, suggesting that these variables explained 12.0% of the variance in FSFI-6 scores. Other variables were not related to FSFI-6 scores.

Table 3 Relationship of FSFI-6 scores with demographic and infertility variables in infertile women using stepwise backward regression analysis
Full size table

Discussion

To our knowledge, this is the first study to evaluate the reliability and validity of the FSFI-6 in a sample of infertile women. The FSFI-6 is a quick and easy to administer instrument and considered a parsimonious alternative to the long form of the FSFI. This scale incorporates one item of each of the six domains of the original FSFI, thus allowing rapid screening of these domains.

The FSFI-6 demonstrated satisfactory internal consistency (α = 0.856), and the alpha value did not increase substantially when each item was removed. All inter-item correlations and corrected item-total correlations were also within an acceptable range, confirming good internal consistency. This result is consistent with what was reported in the original study (α = 0.789) [23], Korean version (α = 0.888) [24], middle-aged Brazilian and Portuguese women (α = 0.840 and α = 0.890, respectively) [25, 26], and Ecuadorian sample (α = 0.91) [36].

The findings of CFA provided support for a unidimensional model of FSFI-6. This finding was also reported in two studies conducted in middle-aged Brazilian and Portuguese women [25, 26].

Among demographic and fertility factors, higher women’s age, low education, unwanted marriage, short infertility duration, and low frequency of intercourse were associated with sexual dysfunction. In a study conducted among mid-aged Ecuadorian women [36], total FSFI-6 scores positively correlated with coital frequency and female and partner educational level and inversely with female age, waist circumference, hot flush intensity, and partner age. In another study performed among mid-aged sexually active Spanish women, total FSFI-6 scores displayed a positive correlation with female and partner education and negative correlation with female age [36]. Contrary to our findings, Iris et al. [15] showed that a long infertility duration was associated with the likelihood of sexual dysfunction in women.

In the present study, several limitations should be pointed out. First, the sample was drawn from a single center and included only infertile women in Iran. Therefore, the generalizability of the present findings may be limited. Second, because of the cross-sectional nature of this study, causal inference between FSFI-6 scores and demographic characteristics of women cannot be drawn. Third, the test-retest reliability of the FSFI-6 was not assessed in this study. Fourth, although the cutoff point is available for the original, Korean, and Ecuadorian versions, further research is required to determine the cutoff point for the Iranian population.

Conclusions

In sum, the FSFI-6 is a reliable and valid instrument that can be used to assess female sexual function in infertile women. Its brevity and comprehensiveness allow a quick assessment both in clinical and research settings.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Abbreviations

CFA:

Confirmatory factor analysis

CFI:

Comparative fit index

FSFI-6:

6-Item Female Sexual Function Index

IFI:

Incremental fit index

NFI:

Normalized fit index

RMSEA:

Root mean square error of approximation

SRMR:

Standardized root mean square residual

References

  1. 1.

    Zegers-Hochschild F, Adamson G, Dyer S, Racowsky C, de Mouzon J, Sokol R, Rienzi L, Sunde A, Schmidt L, Cooke I et al (2017) The International Glossary on Infertility and Fertility Care, 2017. Fertil Steril 108(3):393–406

    PubMed  Article  Google Scholar 

  2. 2.

    Boivin J, Bunting L, Collins JA, Nygren KG (2007) International estimates of infertility prevalence and treatment-seeking: potential need and demand for infertility medical care. Hum Reprod 22(6):1506–1512

    PubMed  Article  Google Scholar 

  3. 3.

    Omani-Samani R, Ghaheri A, Navid B, Sepidarkish M, Maroufizadeh S (2018) Prevalence of generalized anxiety disorder and its related factors among infertile patients in Iran: a cross-sectional study. Health Qual Life Outcomes 16(1):129

    PubMed  PubMed Central  Article  Google Scholar 

  4. 4.

    Maroufizadeh S, Ghaheri A, Almasi-Hashiani A, Mohammadi M, Navid B, Ezabadi Z, Samani RO (2018) The prevalence of anxiety and depression among people with infertility referring to Royan Institute in Tehran, Iran: a cross-sectional questionnaire study. Middle East Fertil Soc J 23(2):103–106

    Article  Google Scholar 

  5. 5.

    Omani-Samani R, Maroufizadeh S, Almasi-Hashiani A, Amini P (2018) Prevalence of depression and its determinant factors among infertile patients in Iran based on the PHQ-9. Middle East Fertil Soc J 23(4):460–463

    Article  Google Scholar 

  6. 6.

    Omani-Samani R, Maroufizadeh S, Ghaheri A, Amini P, Navid B (2017) Reliability and validity of the Kansas Marital Satisfaction Scale (KMSS) in infertile people. Middle East Fertil Soc J 23(2):154–157

    Article  Google Scholar 

  7. 7.

    Maroufizadeh S, Omani-Samani R, Bagheri-Lankarani N, Almasi-Hashiani A, Amini P (2018) Factors associated with poor well-being of infertile people: a cross-sectional study. Middle East Fertil Soc J 23(4):468–470

    Article  Google Scholar 

  8. 8.

    Kim M, Nam H, Youn M (2016) Infertility stress, depression, and resilience in women with infertility treatments. J Korean Public Health Nurs 30(1):93–104

    Article  Google Scholar 

  9. 9.

    Maroufizadeh S, Karimi E, Vesali S, Omani Samani R (2015) Anxiety and depression after failure of assisted reproductive treatment among patients experiencing infertility. Int J Gynaecol Obstet 130(3):253–256

    PubMed  Article  Google Scholar 

  10. 10.

    Sargolzaee MR, Moharreri F, Arshadi HR, Javadi K, Karimi S, Fayyazi-bordbar MR (2001) Psychosexual and depression disorders in infertile female referring to Mashhad Infertility Treatment Center. J Reprod Infertil:2(4)

  11. 11.

    Higgins JA, Wang Y (2015) Which young adults are most likely to use withdrawal? The importance of pregnancy attitudes and sexual pleasure. Contraception 91(4):320–327

    PubMed  Article  Google Scholar 

  12. 12.

    Piva I, Lo Monte G, Graziano A, Marci R (2014) A literature review on the relationship between infertility and sexual dysfunction: does fun end with baby making? Eur J Contracept Reprod Health Care 19(4):231–237

    CAS  PubMed  Article  Google Scholar 

  13. 13.

    Tayebi N, Ardakani SMY (2007) The prevalence of sexual dysfunctions in infertile women. Middle East Fertil Soc J 12(3):184–187

    Google Scholar 

  14. 14.

    Millheiser LS, Helmer AE, Quintero RB, Westphal LM, Milki AA, Lathi RB (2010) Is infertility a risk factor for female sexual dysfunction? A case-control study. Fertil Steril 94(6):2022–2025

    PubMed  Article  Google Scholar 

  15. 15.

    Iris A, Kirmizi DA, Taner CE (2013) Effects of infertility and infertility duration on female sexual functions. Arch Gynecol Obstet 287(4):809–812

    PubMed  Article  Google Scholar 

  16. 16.

    Çayan S, Akbay E, Bozlu M, Canpolat B, Acar D, Ulusoy E (2004) The prevalence of female sexual dysfunction and potential risk factors that may impair sexual function in Turkish women. Urol Int 72(1):52–57

    PubMed  Article  Google Scholar 

  17. 17.

    Munarriz R, Kim NN, Goldstein I, Traish AM (2002) Biology of female sexual function. Urol Clin North Am 29(3):685–693

    PubMed  Article  Google Scholar 

  18. 18.

    Carpenter JS, Jones SM, Studts CR, Heiman JR, Reed SD, Newton KM, Guthrie KA, Larson JC, Cohen LS, Freeman EW (2016) Female Sexual Function Index short version: a MsFLASH item response analysis. Arch Sex Behav 45(8):1897–1905

    PubMed  PubMed Central  Article  Google Scholar 

  19. 19.

    Hayes RD, Bennett CM, Fairley CK, Dennerstein L (2011) Epidemiology: what can prevalence studies tell us about female sexual difficulty and dysfunction? J Sex Med 3(4):589–595

    Article  Google Scholar 

  20. 20.

    Omani-Samani R, Amini P, Navid B, Sepidarkish M, Maroufizadeh S, Almasi-Hashemi A (2019) Prevalence of sexual dysfunction among infertile women in Iran: a systematic review and meta-analysis. Int J Fertil Steril 12(4):278–283

    PubMed  Google Scholar 

  21. 21.

    Stuckey BG (2008) Female sexual function and dysfunction in the reproductive years: the influence of endogenous and exogenous sex hormones. J Sex Med 5(10):2282–2290

    CAS  PubMed  Article  Google Scholar 

  22. 22.

    Neijenhuijs KI, Hooghiemstra N, Holtmaat K, Aaronson NK, Groenvold M, Holzner B, Terwee CB, Cuijpers P, Verdonck-de Leeuw IM (2019) The Female Sexual Function Index (FSFI)—a systematic review of measurement properties. J Sex Med 16(5):640–660

    PubMed  Article  Google Scholar 

  23. 23.

    Isidori A, Pozza C, Esposito K, Ciotola M, Giugliano D, Morano S, Lenzi A, Jannini E (2010) Development and validation of a 6-item version of the Female Sexual Function Index (FSFI) as a diagnostic tool for female sexual dysfunction. J Sex Med 7(3):1139–1146

    PubMed  Article  Google Scholar 

  24. 24.

    Lee Y, Lim MC, Joo J, Park K, Lee S, Seo S, Lee DO, Park S-Y (2014) Development and validation of the Korean version of the Female Sexual Function Index-6 (FSFI-6 K). Yonsei Med J 55(5):1442–1446

    PubMed  PubMed Central  Article  Google Scholar 

  25. 25.

    Dall'Agno ML, Ferreira CF, Ferreira FV, Pérez-López FR, Wender MCO (2019) Validation of the Six-item Female Sexual Function Index in middle-aged Brazilian women. Rev Bras Ginecol Obstet 41(7):432–439

    PubMed  Article  Google Scholar 

  26. 26.

    Pimenta F, Albergaria R, Gomes M, Maroco J, Leal I, Chedraui P, Pérez-López FR (2017) Preliminary validating analysis of the Portuguese language 6-item Female Sexual Function Index (FSFI-6). Maturitas 100:143–144

    Google Scholar 

  27. 27.

    Armeni A, Salazar-Pousada D, Andrade-Ponce SS, Tupacyupanqui-Mera JC, Pérez-López FR, Chedraui P (2017) Reliability and validity of FSFI-6 in mid-aged Ecuadorian women. Maturitas 103:93

    Article  Google Scholar 

  28. 28.

    Guilford JP (1954) Psychometric methods. McGraw Hill, New York

    Google Scholar 

  29. 29.

    Cattell R (1978) Use of factor analysis in behavioral and life sciences. Plenum Press, New York

    Google Scholar 

  30. 30.

    Bentler PM (1990) Comparative fit indexes in structural models. Psychol Bull 107(2):238–246

    CAS  PubMed  Article  Google Scholar 

  31. 31.

    Byrne BM (1994) Structural equation modeling with EQS and EQS/Windows: basic concepts, applications, and programming. Sage Publications, Thousand Oaks

    Google Scholar 

  32. 32.

    McDonald RP, Ho M-HR (2002) Principles and practice in reporting structural equation analyses. Psychol Methods 7(1):64–82

    PubMed  Article  Google Scholar 

  33. 33.

    Kline RB (2015) Principles and practice of structural equation modeling. Guilford Publications, New York

    Google Scholar 

  34. 34.

    Nunally JC, Bernstein IH (1994) Psychometric theory, 3rd edn. McGraw-Hill, New York

    Google Scholar 

  35. 35.

    Kline P (2013) Handbook of psychological testing. Routledge, London

    Google Scholar 

  36. 36.

    Chedraui P, Pérez-López FR, Sánchez H, Aguirre W, Martínez N, Miranda O, Plaza MS, Schwager G, Narváez J, Quintero JC (2012) Assessment of sexual function of mid-aged Ecuadorian women with the 6-item Female Sexual Function Index. Maturitas 71(4):407–412

    PubMed  Article  Google Scholar 

Download references

Acknowledgements

We thank the infertile women who participated in this research and the Royan Institute, Tehran, Iran, for cooperation in data acquisition.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Author information

Affiliations

  1. School of Nursing and Midwifery, Guilan University of Medical Sciences, Rasht, Iran

    Saman Maroufizadeh

  2. Department of Midwifery and Reproductive Health, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran

    Hedyeh Riazi & Hajar Lotfollahi

  3. Department of Medical Ethics and Law, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran

    Reza Omani-Samani

  4. Department of Biostatistics and Epidemiology, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

    Payam Amini

Authors
  1. Saman Maroufizadeh
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  2. Hedyeh Riazi
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  3. Hajar Lotfollahi
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  4. Reza Omani-Samani
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Contributions

SM contributed to the conception and design, analysis and interpretation of the data, and drafting of the article. PA contributed to the conception and design, interpretation of the data, and drafting of the article. HR, ROS, and HL contributed to the conception and design, collection and assembly of data, and drafting of the article. All authors approved the final version of the article for submission.

Corresponding author

Correspondence to Payam Amini.

Ethics declarations

Ethics approval and consent to participate

The Ethics Committee of Royan Institute, Tehran, Iran, approved this study (registration number: IR.ACECR.ROYAN.REC.1395.140). Agreement to participate and written informed consent were obtained from all infertile women before data collection.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

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Maroufizadeh, S., Riazi, H., Lotfollahi, H. et al. The 6-item Female Sexual Function Index (FSFI-6): factor structure, reliability, and demographic correlates among infertile women in Iran. Middle East Fertil Soc J 24, 7 (2020). https://doi.org/10.1186/s43043-019-0008-8

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Keywords

  • Female Sexual Function Index
  • Sexual Dysfunction
  • Reliability
  • Validity
  • Infertility