Qual Life Res DOI 10.1007/s11136-014-0652-5
BRIEF COMMUNICATION
Psychometric properties of the French Female Sexual Function Index (FSFI) Sophie Wylomanski • Re´jane Bouquin • Henri-Jean Philippe • Yves Poulin • Matthieu Hanf Brigitte Dre´no • Roman Rouzier • Gae¨lle Que´reux
•
Accepted: 17 February 2014 Ó Springer International Publishing Switzerland 2014
Abstract Introduction Few validated questionnaires are available in French to assess sexual function. The aim of this study was thus to validate a French version of the Female Sexual Function Index (FSFI) in a sample of French women. Methods In this prospective monocentric and cross-sectional study, an already existing French version of the FSFI, was back-translated and compared to the original version. It was then randomly distributed to 800 women attending Gynecology consultation at Nantes University Hospital in April 2012. Various statistical analyzes were used to test the psychometric properties of the French FSFI. Results 512 questionnaires were completed. Mean FSFI summary score was 25.2. Intraclass correlation coefficients S. Wylomanski (&) R. Bouquin H.-J. Philippe Department of Gynecology and Obstetrics, Nantes University Hospital, 38 boulevard Jean Monnet, 44093 Nantes Cedex 1, France e-mail: [email protected] Y. Poulin FRCPC, Universite´ Laval, Laval, Quebec, QC, Canada M. Hanf Biostatistics, CESP Centre for research in Epidemiology and Population Health, U1018 Inserm, Villejuif, Paris, France B. Dre´no G. Que´reux Skin Cancer Unit INSERM 892, Nantes University Hospital, Nantes, France
were superior to 0.75 and Cronbach’s coefficients superior to 0.8 similarly to the original version. Variance analysis revealed significant differences in summary score between premenopausal and postmenopausal women and according to the marital status. Convergent validity was excellent (100 %) and discriminant validity was satisfactory (89.5 %). The factorial structure corresponded to the original version with six retrieved dimensions. Conclusions Our study demonstrated similar or adequate psychometric properties of the French version of the FSFI compared to the original English version. Keywords Female sexual function Female Sexual Function Index Questionnaire validation French translation
Introduction The prevalence of female sexual dysfunction (FSD) is often underestimated in the female population (20–50 % of women) [1]. A few questionnaires assessing FSD meet the required scientific quality criteria [2]. The ‘‘Female Sexual Function Index’’ (FSFI) is one of them [3]. Nevertheless, no validated French version of the FSFI is currently available limiting its use in French women [4]. The aim of this study was thus to validate a French version of the FSFI to help to better evaluate FSD in French women.
R. Rouzier Department of Surgery, Institut Curie, Paris, France
Methods
R. Rouzier EA 7285 ‘‘Risk and Safety in Clinical Medicine for Women and Perinatal Health’’, University of Versailles St-Quentin, Montigny-le-Bretonneux, France
The original English version of FSFI, created by Raymond Rosen, helps assessing FSD in sexually active women [5]. Six dimensions of the female sexual function (desire,
123
Qual Life Res
arousal, lubrication, orgasm, satisfaction and pain) are evaluated over the last 4 weeks. The FSFI includes 19 items optimally illustrating the 6 dimensions. The summary score ranges between 2 and 36, with low scores indicating more severe FSD. The choice of a pertinent threshold to define a score anomaly seems to have been found for values ranging between 23 and 26.5 [6–8]. A non-validated French version of the original FSFI, usually used in French clinical studies [9–11] and available online, was used as a first-step approach [12]. This nonvalidated version was back-translated by a bilingual English-speaker expert in the field. A particular attention was paid for verifying that the meaning of the original version designed by Rosen et al. was similar in the French version (Appendix 1). To assess the psychometric properties, the French version of the FSFI was tested in a randomly selected sample of female patients consulting in April 2012 at the obstetrics and gynecology department of Nantes General Hospital whatever the reason for consulting. Women who were minor, hospitalized, not able to read or write French, having had a psychiatric or neurological disease and having consulted in emergency were excluded. Socio-demographic data were collected from participants together with medical data. Women who provided a signed informed consent were asked to fill in the French version of the FSFI. A subsample of 100 women chosen randomly was asked to complete a second time the FSFI questionnaire 15 days after their first completion. This study was approved by an ethic committee on human researches. Descriptive analyses were used to study the participant characteristics. The reproducibility (test–retest) of the scores for each scale was carried out by calculating intraclass correlation coefficients (ICC). The internal consistency was assessed by calculating the Cronbach’s coefficient for each scale. Coefficients greater than 0.7 were usually considered as acceptable [13]. Correlations adjusted for overlapping between each item and scales were used to test the convergent and discriminant validity of the FSFI. Convergent validity was revealed if more than 90 % of the item–associated scale correlations were greater than 0.4, while the requirements for discriminant validity were satisfied if more than 80 % of the items were the most correlated with their own scale [13]. Discriminative ability was first tested by calculating floor and ceiling effects for each item. A floor (ceiling) effect was considered as large if more than 50 % of women had the best (the worst) possible value for a given item. Variance analyses were then performed to compare groups of patients with different socio-demographic and medical characteristics known to influence the female sexual function (Appendix 2). Factor analysis was used to examine the construct validity of the French FSFI version. An exploratory factor analysis
123
(EFA) was first conducted using a maximum-likelihood factor analysis with 6 factors and a promax rotation method [13]. Construct validity was then tested by confirmatory factor analysis (CFA) [13]. CFA was performed by specifying the dimensional model expected for the FSFI, which is to say 6 scales composed of their respective items. Correlations between each item and its associated scale were determined using maximum-likelihood estimation. The following adjustment indexes were also calculated: the v2/df (Q) (2 \ Q \ 5 is considered acceptable), the root mean square error of approximation (RMSEA) (a value between 0.05 and 0.1 is considered a good adjustment), the comparative fit index (CFI) (a value greater than 0.9 is considered a good adjustment), and the standardized root mean square residual (SRMR) (values less than 0.1 are considered satisfactory) [14]. To improve this model, modification indices based on Lagrange multiplier were used (Appendix 3). The level of significance was defined at 0.05. The statistical analyses were performed using R.14.1 software [15].
Results A total of 800 FSFI questionnaires were distributed, and 512 (64 %) accepted to return them. No particular issues were identified during the back translation, and no changes were made to the initial French version. Women mean age was 35 years. In the sample, the mean summary score was 28.4 (Table 1). The ICC of each scale were all greater than 0.75. Cronbach’s alpha coefficient ranged between 0.84 and 0.97 for the six item subscales and was 0.97 for the summary scale (Table 2). Correlations between each item and its associated subscore were all greater than 0.4, resulting in a convergent validity of 100 %. Only two items had a higher correlation with a subscore different from their associated subscore (items 14 and 15), resulting in a discriminant validity of 89.5 %. All floor effects were less than 15 % and only 2 items had a ceiling effect greater than 50 % (items 9 and item 10). Furthermore, significant differences in summary score between premenopausal and postmenopausal women (D score = 4, p = 0.01), and according to the marital status (D score = 8, p \ 0.001), were found. The 19 items were distributed over all 6 factors (Table 3). The 6 factors obtained explained 71.4 % of the variance. The items related to desire, arousal, lubrication and pain were, respectively, more correlated with factor 5, 6, 1 and 3. Two of the three items related to satisfaction were more correlated with factor 4. The third one (item 14) was more correlated with factor 2 while it also correlated with factor 4 (r = 0.2). Concerning the CFA, the results did not reflect the expected match between the model and the data. Indeed, the Q value was greater than 5 and all other
Qual Life Res Table 1 Socio-demographic, medical and FSFI characteristics of the sample (N = 504) Variable
Table 1 continued Variable
(N = 504)
(N = 504) Pain
Socio-demographic variables
Mean
Age (years) Mean
35
SD
10
Marital status (%) Single/widowed
10.9
In couple Married
45.3 43.8
Type of work (%) Student
6.2
Regular job
75.4
No job/retired
18.4
Nulligravida
13.9
Primigravida
26.6
Multigravida
59.5
Parity (%) Nulliparous
31.5
Primiparous
25.7
Multiparous
42.8
Menopausal status (%) Premenopausal women Postmenopausal women
91.1 8.9
Pregnancy status (%) No
52
Yes
39.1
Not known
8.9
FSFI scores Desire Mean
3.8
SD
1.1
25.2
SD
8.9
Table 2 Cronbach’s alpha and intraclass correlation coefficients of the FSFI scales in the French sample and in the sample of the original version Domain
Cronbach’s alpha
ICC
Original version
French version
Original version
French version
Desire
0.92
0.88
0.83
0.97
Arousal
0.95
0.96
0.85
0.99
Lubrication
0.96
0.97
0.86
0.97
Orgasm
0.94
0.94
0.8
0.96
Mean
4.1
SD
1.7
Lubrication SD Orgasm
Satisfaction
0.89
0.84
0.83
0.89
Pain
0.94
0.97
0.79
0.99
All Items
0.97
0.97
0.88
0.99
indices, except the CFI, exceeded their respective threshold value of acceptability. The CFA model was thus adjusted based on modification indices that suggested adding a covariance between error terms for 4 item pairs: 7–10, 15–16, 3–4 and 8–9. Each pair of items included a similar content. With Q = 2.8, CFI = 0.98, RMSEA = 0.06 and SRMR = 0.03, this modified model satisfactorily fitted the data.
Discussion
Arousal
Mean
2.1
Mean
Medical variables Gravidity (%)
4.2
SD Summary score
4.5 2
Mean
4.1
SD
2
Satisfaction Mean
4.6
SD
1.5
The present study showed that this French version of the original English version of the FSFI maintained the high psychometric properties of the original version. The internal consistency shown by Cronbach’s alpha was higher than the value of 0.7 used as reliability threshold [13]. Moreover, although increasing alpha can result automatically from the higher number of items, Cronbach’s alpha was 0.97 for the summary scale and was comparable to that of the original English version indicating that both versions had a similar reliability
123
Qual Life Res Table 3 Factor loadings obtained with exploratory factor analysis (EFA) using a maximum-likelihood factor analysis with 6 factors and a promax rotation method (N = 504) Item
Subscale
Factor 1
Factor 2
Factor 3
Factor 4
Factor 5
Factor 6
Item 1
Desire
–
–
–
–
0.73
–
Item 2
Desire
–
–
–
–
1.03
–
Item 3
Arousal
–
–
–
–
–
0.68
Item 4
Arousal
–
–
–
–
–
0.65
Item 5
Arousal
0.32
–
–
–
–
0.4
Item 6
Arousal
–
0.32
–
–
–
0.45
Item 7 Item 8
Lubrication Lubrication
0.73 0.88
– –
– –
– –
– –
– –
Item 9
Lubrication
0.86
–
–
–
–
–
Item 10
Lubrication
0.97
–
–
–
–
–
Item 11
Orgasm
–
0.95
–
–
–
–
Item 12
Orgasm
–
0.96
–
–
–
–
Item 13
Orgasm
–
0.77
–
–
–
–
Item 14
Satisfaction
–
0.34
–
–
–
–
Item 15
Satisfaction
–
–
–
0.92
–
–
Item 16
Satisfaction
–
–
–
1.00
–
–
Item 17
Pain
–
–
0.9
–
–
–
Item 18
Pain
–
–
0.87
–
–
–
Item 19
Pain
–
–
0.95
–
–
–
Only factor loadings greater than 0.30 are represented
[5]. The French version scores had a satisfactory reproducibility with ICC between 0.89 and 0.99. These ICC were also similar to those of the original English version. Strong coherences in the grouping of the 19 items into six dimensions of the female sexual function were also found, confirming the construct validity of this French version. In our study, the different factor analyzes supported the theoretical model. The EFA conducted in the validated original version only supported a 5-factor solution, in which the items related to desire and arousal were regrouped in a single dimension [5]. Based on clinical observations, Rosen et al. decided however to split this latter into two distinct dimensions (arousal and desire). The distinction of arousal from desire was facilitated in the French version with the use of a promax rotation allowing for non-orthogonal factors (unlike the varimax rotation used in the original FSFI version). The comparison analysis between groups indicated that the French FSFI version is a valid tool for measuring FSD since the questionnaire helps discriminating between socio-demographically and clinically different patients [16–18] (Appendix 3). This study thus confirmed that the age and menopausal status negatively influenced the FSFI scores. However, these results have some limitations. First, the study population was not perfectly representative of the real French adult woman population. Indeed, a previous
123
report [19] indicated that women over 65 years represent about 26 % of the French adult women population, whereas they only represented 1 % of our study sample. Furthermore, the percentage of pregnant women was much higher in the study sample (39.1 %) than in the French women population (4 %). It is however argued that this bias was not too detrimental for the study because (1) the original English FSFI version included pregnant women [5], (2) sexuality is commonly accepted as highly heterogeneous according to specificities of surveyed women and the pregnancy stage and (3) no significant differences in FSFI scores between pregnant and non-pregnant patients were observed in the study. Second, a non-consensual method for the process of linguistic validation was used here [20]. Due to the existence of a non-validated French version already largely used by French clinicians [9–11], it was preferred to validate this one instead of making a traditional forward– backward translation. Furthermore, due to previous studies having shown the satisfactory acceptability of this French version [9–11], this last was also not tested. These findings show that the French version of the FSFI developed is a reliable and valid tool for measuring FSD in the French population. It can be used for research, teaching as well as clinical practice purposes. Conflict of interest
None declared.
Qual Life Res
Appendix 1
123
Qual Life Res
123
Qual Life Res
123
Qual Life Res
Appendix 2
Appendix 3
See Table 4.
See Table 5.
Table 4 Analysis of variance of the FSFI summary score by age, menopausal status, pregnancy status, use of a contraceptive method, desire of pregnancy and marital status (N = 504)
Table 5 CFA Goodness-of-fit indices for the French FSFI version (N = 504)
Variable
Mean summary score
Age \30 years
24.9
30–39 years
25.7
40–49 years C50 years
25.9 22.6 25.5
Postmenopausal women
21.5 25.8
6.360
0.943
0.103 [0.097–0.110]
0.098
2.797
0.982
0.060 [0.053–0.067]
0.027
0.42 0.48 0.09*
RMSEA root mean square error of approximation (good quality criteria: value between 0.05 and 0.1) CFI comparative fit index (good quality criteria: value greater than 0.9)
0.01**
SRMR standardized root mean square residual (good quality criteria: values less than 0.1)
Pregnant
25.2
Model included specified covariance between error terms for 4 item pairs: 7–10, 15–16, 3–4 and 8–9
0.45
Marital status
References
Single/widowed
17.2
In couple
27.4
\0.001**
Married
24.9
\0.001**
123
SRMR
a
Not pregnant
** P value greater than 0.05
RMSEA
6 factors with covaried errora
Pregnancy status
* P value less than 0.10
CFI
6 factors
Menopausal status Premenopausal women
v2/df
P value
1. Laumann, E. O., Paik, A., & Rosen, R. C. (1999). Sexual dysfunction in the United States: Prevalence and predictors. JAMA, 281(6), 537–544. 2. Althof, S. E., Rosen, R. C., DeRogatis, L., Corty, E., Quirk, F., & Symonds, T. (2005). Outcome measurement in female sexual
Qual Life Res
3.
4.
5.
6.
7.
8.
9.
10.
dysfunction clinical trials: Review and recommendations. Journal of Sex and Marital Therapy, 31(2), 153–166. Ficek, L., Miotła, P., & Rechberger, T. (2005). Women’s sexual life quality assessment with use of questionnaires in clinical trials–review of accessible tools, their characteristics and comparison of their properties. Ginekologia Polska, 76(12), 1000–1007. Caremel, R., Berthier, A., Sentilhes, L., Collard, P., & Grise, P. (2008). Analysis of a French female sexuality reference population. Progre`s en urologie, 18(8), 527–535. doi:10.1016/j.purol. 2008.03.035. Rosen, R., Brown, C., Heiman, J., Leiblum, S., Meston, C., Shabsigh, R., et al. (2000). The Female Sexual Function Index (FSFI): A multidimensional self-report instrument for the assessment of female sexual function. Journal of Sex and Marital Therapy, 26(2), 191–208. doi:10.1080/009262300278597. Chedraui, P., Pe´rez-Lo´pez, F. R., Mezones-Holguin, E., San Miguel, G., & Avila, C. (2011). Assessing predictors of sexual function in mid-aged sexually active women. Maturitas, 68(4), 387–390. doi:10.1016/j.maturitas.2010.12.004. Aslan, E., Beji, N. K., Gungor, I., Kadioglu, A., & Dikencik, B. K. (2008). Prevalence and risk factors for low sexual function in women: A study of 1,009 women in an outpatient clinic of a university hospital in Istanbul. The Journal of Sexual Medicine, 5(9), 2044–2052. doi:10.1111/j.1743-6109.2008.00873.x. Esposito, K., Ciotola, M., Giugliano, F., Bisogni, C., Schisano, B., Autorino, R., et al. (2007). Association of body weight with sexual function in women. International Journal of Impotence Research, 19(4), 353–357. doi:10.1038/sj.ijir.3901548. Trudel, G., Dargis, L., Cadieux, J., Villeneuve, L., Pre´ville, M., & Boyer, R. (2012). Validation de l’Index de la fonction sexuelle fe´minine (IFSF) et pre´sentation de normes chez les femmes aıˆne´es. Sexologies, 21(3), 161–167. doi:10.1016/j.sexol.2012.01.003. Lavoue´, V., Lemarrec, A., Bertheuil, N., Henno, S., Mesbah, H., Watier, E., et al. (2013). Quality of life and female sexual function after skinning vulvectomy with split-thickness skin graft in women with vulvar intraepithelial neoplasia or vulvar Paget
11.
12. 13.
14.
15.
16.
17.
18. 19.
20.
disease. European Journal of Surgical Oncology,. doi:10.1016/j. ejso.2013.09.014. Morcel, K., Lavoue´, V., Jaffre, F., Paniel, B.-J., & Rouzier, R. (2013). Sexual and functional results after creation of a neovagina in women with Mayer-Rokitansky-Ku¨ster-Hauser syndrome: A comparison of nonsurgical and surgical procedures. European Journal of Obstetrics, Gynecology, and Reproductive Biology, 169(2), 317–320. doi:10.1016/j.ejogrb.2013.03.005. FSFI auto questionnaire. (2012, aouˆt 5). urofrance.org. Consulte´ 8 janvier 2013, a` l’adresse about: blank. Fayers, P., & Machin, D. (2007). Quality of life: The assessment, analysis, and interpretation of patient-reported outcomes (2nd ed.). Hoboken: Wiley-Blackwell. Hu, L., & Bentler, P. M. (1999). Cutoff criteria for fit indexes in covariance structure analysis: Conventional criteria versus new alternatives. Structural Equation Modeling: A Multidisciplinary Journal, 6(1), 1–55. doi:10.1080/10705519909540118. R Development Core Team. (2011). R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing. Berman, J. R., & Bassuk, J. (2002). Physiology and pathophysiology of female sexual function and dysfunction. World Journal of Urology, 20(2), 111–118. doi:10.1007/s00345-002-0281-4. Berman, J. R., Berman, L. A., Werbin, T. J., & Goldstein, I. (1999). Female sexual dysfunction: Anatomy, physiology, evaluation and treatment options. Current Opinion in Urology, 9(6), 563–568. Sarrel, P. M. (1990). Sexuality and menopause. Obstetrics and gynecology, 75(4 Suppl), 26S–30S; discussion 31S–35S. INSEE. (2013). Internet website of the National Institute of Statistics and Economic Studies (INSEE). Consulte´ 1 aouˆt 2013, a` l’adresse. Guillemin, F., Bombardier, C., & Beaton, D. (1993). Cross-cultural adaptation of health-related quality of life measures: Literature review and proposed guidelines. Journal of Clinical Epidemiology, 46(12), 1417–1432.
123
BRIEF COMMUNICATION
Psychometric properties of the French Female Sexual Function Index (FSFI) Sophie Wylomanski • Re´jane Bouquin • Henri-Jean Philippe • Yves Poulin • Matthieu Hanf Brigitte Dre´no • Roman Rouzier • Gae¨lle Que´reux
•
Accepted: 17 February 2014 Ó Springer International Publishing Switzerland 2014
Abstract Introduction Few validated questionnaires are available in French to assess sexual function. The aim of this study was thus to validate a French version of the Female Sexual Function Index (FSFI) in a sample of French women. Methods In this prospective monocentric and cross-sectional study, an already existing French version of the FSFI, was back-translated and compared to the original version. It was then randomly distributed to 800 women attending Gynecology consultation at Nantes University Hospital in April 2012. Various statistical analyzes were used to test the psychometric properties of the French FSFI. Results 512 questionnaires were completed. Mean FSFI summary score was 25.2. Intraclass correlation coefficients S. Wylomanski (&) R. Bouquin H.-J. Philippe Department of Gynecology and Obstetrics, Nantes University Hospital, 38 boulevard Jean Monnet, 44093 Nantes Cedex 1, France e-mail: [email protected] Y. Poulin FRCPC, Universite´ Laval, Laval, Quebec, QC, Canada M. Hanf Biostatistics, CESP Centre for research in Epidemiology and Population Health, U1018 Inserm, Villejuif, Paris, France B. Dre´no G. Que´reux Skin Cancer Unit INSERM 892, Nantes University Hospital, Nantes, France
were superior to 0.75 and Cronbach’s coefficients superior to 0.8 similarly to the original version. Variance analysis revealed significant differences in summary score between premenopausal and postmenopausal women and according to the marital status. Convergent validity was excellent (100 %) and discriminant validity was satisfactory (89.5 %). The factorial structure corresponded to the original version with six retrieved dimensions. Conclusions Our study demonstrated similar or adequate psychometric properties of the French version of the FSFI compared to the original English version. Keywords Female sexual function Female Sexual Function Index Questionnaire validation French translation
Introduction The prevalence of female sexual dysfunction (FSD) is often underestimated in the female population (20–50 % of women) [1]. A few questionnaires assessing FSD meet the required scientific quality criteria [2]. The ‘‘Female Sexual Function Index’’ (FSFI) is one of them [3]. Nevertheless, no validated French version of the FSFI is currently available limiting its use in French women [4]. The aim of this study was thus to validate a French version of the FSFI to help to better evaluate FSD in French women.
R. Rouzier Department of Surgery, Institut Curie, Paris, France
Methods
R. Rouzier EA 7285 ‘‘Risk and Safety in Clinical Medicine for Women and Perinatal Health’’, University of Versailles St-Quentin, Montigny-le-Bretonneux, France
The original English version of FSFI, created by Raymond Rosen, helps assessing FSD in sexually active women [5]. Six dimensions of the female sexual function (desire,
123
Qual Life Res
arousal, lubrication, orgasm, satisfaction and pain) are evaluated over the last 4 weeks. The FSFI includes 19 items optimally illustrating the 6 dimensions. The summary score ranges between 2 and 36, with low scores indicating more severe FSD. The choice of a pertinent threshold to define a score anomaly seems to have been found for values ranging between 23 and 26.5 [6–8]. A non-validated French version of the original FSFI, usually used in French clinical studies [9–11] and available online, was used as a first-step approach [12]. This nonvalidated version was back-translated by a bilingual English-speaker expert in the field. A particular attention was paid for verifying that the meaning of the original version designed by Rosen et al. was similar in the French version (Appendix 1). To assess the psychometric properties, the French version of the FSFI was tested in a randomly selected sample of female patients consulting in April 2012 at the obstetrics and gynecology department of Nantes General Hospital whatever the reason for consulting. Women who were minor, hospitalized, not able to read or write French, having had a psychiatric or neurological disease and having consulted in emergency were excluded. Socio-demographic data were collected from participants together with medical data. Women who provided a signed informed consent were asked to fill in the French version of the FSFI. A subsample of 100 women chosen randomly was asked to complete a second time the FSFI questionnaire 15 days after their first completion. This study was approved by an ethic committee on human researches. Descriptive analyses were used to study the participant characteristics. The reproducibility (test–retest) of the scores for each scale was carried out by calculating intraclass correlation coefficients (ICC). The internal consistency was assessed by calculating the Cronbach’s coefficient for each scale. Coefficients greater than 0.7 were usually considered as acceptable [13]. Correlations adjusted for overlapping between each item and scales were used to test the convergent and discriminant validity of the FSFI. Convergent validity was revealed if more than 90 % of the item–associated scale correlations were greater than 0.4, while the requirements for discriminant validity were satisfied if more than 80 % of the items were the most correlated with their own scale [13]. Discriminative ability was first tested by calculating floor and ceiling effects for each item. A floor (ceiling) effect was considered as large if more than 50 % of women had the best (the worst) possible value for a given item. Variance analyses were then performed to compare groups of patients with different socio-demographic and medical characteristics known to influence the female sexual function (Appendix 2). Factor analysis was used to examine the construct validity of the French FSFI version. An exploratory factor analysis
123
(EFA) was first conducted using a maximum-likelihood factor analysis with 6 factors and a promax rotation method [13]. Construct validity was then tested by confirmatory factor analysis (CFA) [13]. CFA was performed by specifying the dimensional model expected for the FSFI, which is to say 6 scales composed of their respective items. Correlations between each item and its associated scale were determined using maximum-likelihood estimation. The following adjustment indexes were also calculated: the v2/df (Q) (2 \ Q \ 5 is considered acceptable), the root mean square error of approximation (RMSEA) (a value between 0.05 and 0.1 is considered a good adjustment), the comparative fit index (CFI) (a value greater than 0.9 is considered a good adjustment), and the standardized root mean square residual (SRMR) (values less than 0.1 are considered satisfactory) [14]. To improve this model, modification indices based on Lagrange multiplier were used (Appendix 3). The level of significance was defined at 0.05. The statistical analyses were performed using R.14.1 software [15].
Results A total of 800 FSFI questionnaires were distributed, and 512 (64 %) accepted to return them. No particular issues were identified during the back translation, and no changes were made to the initial French version. Women mean age was 35 years. In the sample, the mean summary score was 28.4 (Table 1). The ICC of each scale were all greater than 0.75. Cronbach’s alpha coefficient ranged between 0.84 and 0.97 for the six item subscales and was 0.97 for the summary scale (Table 2). Correlations between each item and its associated subscore were all greater than 0.4, resulting in a convergent validity of 100 %. Only two items had a higher correlation with a subscore different from their associated subscore (items 14 and 15), resulting in a discriminant validity of 89.5 %. All floor effects were less than 15 % and only 2 items had a ceiling effect greater than 50 % (items 9 and item 10). Furthermore, significant differences in summary score between premenopausal and postmenopausal women (D score = 4, p = 0.01), and according to the marital status (D score = 8, p \ 0.001), were found. The 19 items were distributed over all 6 factors (Table 3). The 6 factors obtained explained 71.4 % of the variance. The items related to desire, arousal, lubrication and pain were, respectively, more correlated with factor 5, 6, 1 and 3. Two of the three items related to satisfaction were more correlated with factor 4. The third one (item 14) was more correlated with factor 2 while it also correlated with factor 4 (r = 0.2). Concerning the CFA, the results did not reflect the expected match between the model and the data. Indeed, the Q value was greater than 5 and all other
Qual Life Res Table 1 Socio-demographic, medical and FSFI characteristics of the sample (N = 504) Variable
Table 1 continued Variable
(N = 504)
(N = 504) Pain
Socio-demographic variables
Mean
Age (years) Mean
35
SD
10
Marital status (%) Single/widowed
10.9
In couple Married
45.3 43.8
Type of work (%) Student
6.2
Regular job
75.4
No job/retired
18.4
Nulligravida
13.9
Primigravida
26.6
Multigravida
59.5
Parity (%) Nulliparous
31.5
Primiparous
25.7
Multiparous
42.8
Menopausal status (%) Premenopausal women Postmenopausal women
91.1 8.9
Pregnancy status (%) No
52
Yes
39.1
Not known
8.9
FSFI scores Desire Mean
3.8
SD
1.1
25.2
SD
8.9
Table 2 Cronbach’s alpha and intraclass correlation coefficients of the FSFI scales in the French sample and in the sample of the original version Domain
Cronbach’s alpha
ICC
Original version
French version
Original version
French version
Desire
0.92
0.88
0.83
0.97
Arousal
0.95
0.96
0.85
0.99
Lubrication
0.96
0.97
0.86
0.97
Orgasm
0.94
0.94
0.8
0.96
Mean
4.1
SD
1.7
Lubrication SD Orgasm
Satisfaction
0.89
0.84
0.83
0.89
Pain
0.94
0.97
0.79
0.99
All Items
0.97
0.97
0.88
0.99
indices, except the CFI, exceeded their respective threshold value of acceptability. The CFA model was thus adjusted based on modification indices that suggested adding a covariance between error terms for 4 item pairs: 7–10, 15–16, 3–4 and 8–9. Each pair of items included a similar content. With Q = 2.8, CFI = 0.98, RMSEA = 0.06 and SRMR = 0.03, this modified model satisfactorily fitted the data.
Discussion
Arousal
Mean
2.1
Mean
Medical variables Gravidity (%)
4.2
SD Summary score
4.5 2
Mean
4.1
SD
2
Satisfaction Mean
4.6
SD
1.5
The present study showed that this French version of the original English version of the FSFI maintained the high psychometric properties of the original version. The internal consistency shown by Cronbach’s alpha was higher than the value of 0.7 used as reliability threshold [13]. Moreover, although increasing alpha can result automatically from the higher number of items, Cronbach’s alpha was 0.97 for the summary scale and was comparable to that of the original English version indicating that both versions had a similar reliability
123
Qual Life Res Table 3 Factor loadings obtained with exploratory factor analysis (EFA) using a maximum-likelihood factor analysis with 6 factors and a promax rotation method (N = 504) Item
Subscale
Factor 1
Factor 2
Factor 3
Factor 4
Factor 5
Factor 6
Item 1
Desire
–
–
–
–
0.73
–
Item 2
Desire
–
–
–
–
1.03
–
Item 3
Arousal
–
–
–
–
–
0.68
Item 4
Arousal
–
–
–
–
–
0.65
Item 5
Arousal
0.32
–
–
–
–
0.4
Item 6
Arousal
–
0.32
–
–
–
0.45
Item 7 Item 8
Lubrication Lubrication
0.73 0.88
– –
– –
– –
– –
– –
Item 9
Lubrication
0.86
–
–
–
–
–
Item 10
Lubrication
0.97
–
–
–
–
–
Item 11
Orgasm
–
0.95
–
–
–
–
Item 12
Orgasm
–
0.96
–
–
–
–
Item 13
Orgasm
–
0.77
–
–
–
–
Item 14
Satisfaction
–
0.34
–
–
–
–
Item 15
Satisfaction
–
–
–
0.92
–
–
Item 16
Satisfaction
–
–
–
1.00
–
–
Item 17
Pain
–
–
0.9
–
–
–
Item 18
Pain
–
–
0.87
–
–
–
Item 19
Pain
–
–
0.95
–
–
–
Only factor loadings greater than 0.30 are represented
[5]. The French version scores had a satisfactory reproducibility with ICC between 0.89 and 0.99. These ICC were also similar to those of the original English version. Strong coherences in the grouping of the 19 items into six dimensions of the female sexual function were also found, confirming the construct validity of this French version. In our study, the different factor analyzes supported the theoretical model. The EFA conducted in the validated original version only supported a 5-factor solution, in which the items related to desire and arousal were regrouped in a single dimension [5]. Based on clinical observations, Rosen et al. decided however to split this latter into two distinct dimensions (arousal and desire). The distinction of arousal from desire was facilitated in the French version with the use of a promax rotation allowing for non-orthogonal factors (unlike the varimax rotation used in the original FSFI version). The comparison analysis between groups indicated that the French FSFI version is a valid tool for measuring FSD since the questionnaire helps discriminating between socio-demographically and clinically different patients [16–18] (Appendix 3). This study thus confirmed that the age and menopausal status negatively influenced the FSFI scores. However, these results have some limitations. First, the study population was not perfectly representative of the real French adult woman population. Indeed, a previous
123
report [19] indicated that women over 65 years represent about 26 % of the French adult women population, whereas they only represented 1 % of our study sample. Furthermore, the percentage of pregnant women was much higher in the study sample (39.1 %) than in the French women population (4 %). It is however argued that this bias was not too detrimental for the study because (1) the original English FSFI version included pregnant women [5], (2) sexuality is commonly accepted as highly heterogeneous according to specificities of surveyed women and the pregnancy stage and (3) no significant differences in FSFI scores between pregnant and non-pregnant patients were observed in the study. Second, a non-consensual method for the process of linguistic validation was used here [20]. Due to the existence of a non-validated French version already largely used by French clinicians [9–11], it was preferred to validate this one instead of making a traditional forward– backward translation. Furthermore, due to previous studies having shown the satisfactory acceptability of this French version [9–11], this last was also not tested. These findings show that the French version of the FSFI developed is a reliable and valid tool for measuring FSD in the French population. It can be used for research, teaching as well as clinical practice purposes. Conflict of interest
None declared.
Qual Life Res
Appendix 1
123
Qual Life Res
123
Qual Life Res
123
Qual Life Res
Appendix 2
Appendix 3
See Table 4.
See Table 5.
Table 4 Analysis of variance of the FSFI summary score by age, menopausal status, pregnancy status, use of a contraceptive method, desire of pregnancy and marital status (N = 504)
Table 5 CFA Goodness-of-fit indices for the French FSFI version (N = 504)
Variable
Mean summary score
Age \30 years
24.9
30–39 years
25.7
40–49 years C50 years
25.9 22.6 25.5
Postmenopausal women
21.5 25.8
6.360
0.943
0.103 [0.097–0.110]
0.098
2.797
0.982
0.060 [0.053–0.067]
0.027
0.42 0.48 0.09*
RMSEA root mean square error of approximation (good quality criteria: value between 0.05 and 0.1) CFI comparative fit index (good quality criteria: value greater than 0.9)
0.01**
SRMR standardized root mean square residual (good quality criteria: values less than 0.1)
Pregnant
25.2
Model included specified covariance between error terms for 4 item pairs: 7–10, 15–16, 3–4 and 8–9
0.45
Marital status
References
Single/widowed
17.2
In couple
27.4
\0.001**
Married
24.9
\0.001**
123
SRMR
a
Not pregnant
** P value greater than 0.05
RMSEA
6 factors with covaried errora
Pregnancy status
* P value less than 0.10
CFI
6 factors
Menopausal status Premenopausal women
v2/df
P value
1. Laumann, E. O., Paik, A., & Rosen, R. C. (1999). Sexual dysfunction in the United States: Prevalence and predictors. JAMA, 281(6), 537–544. 2. Althof, S. E., Rosen, R. C., DeRogatis, L., Corty, E., Quirk, F., & Symonds, T. (2005). Outcome measurement in female sexual
Qual Life Res
3.
4.
5.
6.
7.
8.
9.
10.
dysfunction clinical trials: Review and recommendations. Journal of Sex and Marital Therapy, 31(2), 153–166. Ficek, L., Miotła, P., & Rechberger, T. (2005). Women’s sexual life quality assessment with use of questionnaires in clinical trials–review of accessible tools, their characteristics and comparison of their properties. Ginekologia Polska, 76(12), 1000–1007. Caremel, R., Berthier, A., Sentilhes, L., Collard, P., & Grise, P. (2008). Analysis of a French female sexuality reference population. Progre`s en urologie, 18(8), 527–535. doi:10.1016/j.purol. 2008.03.035. Rosen, R., Brown, C., Heiman, J., Leiblum, S., Meston, C., Shabsigh, R., et al. (2000). The Female Sexual Function Index (FSFI): A multidimensional self-report instrument for the assessment of female sexual function. Journal of Sex and Marital Therapy, 26(2), 191–208. doi:10.1080/009262300278597. Chedraui, P., Pe´rez-Lo´pez, F. R., Mezones-Holguin, E., San Miguel, G., & Avila, C. (2011). Assessing predictors of sexual function in mid-aged sexually active women. Maturitas, 68(4), 387–390. doi:10.1016/j.maturitas.2010.12.004. Aslan, E., Beji, N. K., Gungor, I., Kadioglu, A., & Dikencik, B. K. (2008). Prevalence and risk factors for low sexual function in women: A study of 1,009 women in an outpatient clinic of a university hospital in Istanbul. The Journal of Sexual Medicine, 5(9), 2044–2052. doi:10.1111/j.1743-6109.2008.00873.x. Esposito, K., Ciotola, M., Giugliano, F., Bisogni, C., Schisano, B., Autorino, R., et al. (2007). Association of body weight with sexual function in women. International Journal of Impotence Research, 19(4), 353–357. doi:10.1038/sj.ijir.3901548. Trudel, G., Dargis, L., Cadieux, J., Villeneuve, L., Pre´ville, M., & Boyer, R. (2012). Validation de l’Index de la fonction sexuelle fe´minine (IFSF) et pre´sentation de normes chez les femmes aıˆne´es. Sexologies, 21(3), 161–167. doi:10.1016/j.sexol.2012.01.003. Lavoue´, V., Lemarrec, A., Bertheuil, N., Henno, S., Mesbah, H., Watier, E., et al. (2013). Quality of life and female sexual function after skinning vulvectomy with split-thickness skin graft in women with vulvar intraepithelial neoplasia or vulvar Paget
11.
12. 13.
14.
15.
16.
17.
18. 19.
20.
disease. European Journal of Surgical Oncology,. doi:10.1016/j. ejso.2013.09.014. Morcel, K., Lavoue´, V., Jaffre, F., Paniel, B.-J., & Rouzier, R. (2013). Sexual and functional results after creation of a neovagina in women with Mayer-Rokitansky-Ku¨ster-Hauser syndrome: A comparison of nonsurgical and surgical procedures. European Journal of Obstetrics, Gynecology, and Reproductive Biology, 169(2), 317–320. doi:10.1016/j.ejogrb.2013.03.005. FSFI auto questionnaire. (2012, aouˆt 5). urofrance.org. Consulte´ 8 janvier 2013, a` l’adresse about: blank. Fayers, P., & Machin, D. (2007). Quality of life: The assessment, analysis, and interpretation of patient-reported outcomes (2nd ed.). Hoboken: Wiley-Blackwell. Hu, L., & Bentler, P. M. (1999). Cutoff criteria for fit indexes in covariance structure analysis: Conventional criteria versus new alternatives. Structural Equation Modeling: A Multidisciplinary Journal, 6(1), 1–55. doi:10.1080/10705519909540118. R Development Core Team. (2011). R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing. Berman, J. R., & Bassuk, J. (2002). Physiology and pathophysiology of female sexual function and dysfunction. World Journal of Urology, 20(2), 111–118. doi:10.1007/s00345-002-0281-4. Berman, J. R., Berman, L. A., Werbin, T. J., & Goldstein, I. (1999). Female sexual dysfunction: Anatomy, physiology, evaluation and treatment options. Current Opinion in Urology, 9(6), 563–568. Sarrel, P. M. (1990). Sexuality and menopause. Obstetrics and gynecology, 75(4 Suppl), 26S–30S; discussion 31S–35S. INSEE. (2013). Internet website of the National Institute of Statistics and Economic Studies (INSEE). Consulte´ 1 aouˆt 2013, a` l’adresse. Guillemin, F., Bombardier, C., & Beaton, D. (1993). Cross-cultural adaptation of health-related quality of life measures: Literature review and proposed guidelines. Journal of Clinical Epidemiology, 46(12), 1417–1432.
123
