Introduction

Female sexual dysfunction (FSD) is a common multifactorial phenomenon in different populations. FSD encompasses four main phases of orgasmic disorders, sexual arousal disorders, sexual desire disorders and sexual pain disorders (1). In the United States, prevalence rate of FSD has been reported to be 43%, while it has been estimated at 5.8% in the United Kingdom (2, 3). As such, it has been proclaimed that approximately 15% of the general population in the United Kingdom suffers from lifelong sexual dysfunction (3). In a study conducted in Iran in 2006, 31.5% of the general population were reported to have FSD (4).

Negligence or misdiagnosis of FSD could lead to critical conditions for individuals and their family members. Poor sexual health in some regions, especially those with specific cultural inclinations, may result in emotional rejection or divorce (5). According to statistics, as much as 40% of Iranian couples have extramarital affairs due to sexual dysfunction (6).

Laboratory findings on FSD are available in the literature; however, subjective data obtained from women with FSD has been shown to bear higher validity in the accurate diagnosis of FSD compared to laboratory measurements (7). The accepted gold standard for FSD diagnosis is the assessment of patients through interviews conducted by trained sexual therapists in accordance with the criteria of diagnostic and statistical manual of mental disorders (DSM-IV) (8).

One of the alternative methods for FSD assessment is based on questionnaires. Various questionnaires are available for evaluation of FSD. For instance, female sexual function index (FSFI) is one of the most credible questionnaires in this regard, which has been shown to have acceptable internal consistency (Cronbach’s alpha: 0.89-0.98 for total score and scores in each domain). In addition, FSFI has adequate discrimination properties in all its domains. This questionnaire has been validated for the Iranian population, and normative data for this population is available as well (9, 10).

Few studies have evaluated the rate of FSD in healthy, adult women in Iran and they were mostly conducted in Tehran city (4, 11). Given the substantial effect of FSD on familial and personal relations, as well as the scarcity of regional data on this disorder in the North-eastern part of Iran, this study aimed to determine the prevalence of FSD and its risk factors in Sabzevar city, Iran.

Materials and Methods

This cross-sectional study was conducted on 264 women referring to 11 health centers in Sabzevar, Iran during October 2012-January 2013. Health centers were selected based on their geographical location from the north, center and south regions of the city. Married women with sexually active partners who agreed to participate were enrolled in the study, and written informed consent was obtained from all the subjects who met the inclusion criteria. Exclusion criteria of this study were as follows: 1) pregnancy; 2) history of sexual dysfunction; 3) breastfeeding and 4) drug addiction or alcoholism. Subjects completed FSFI and demographic questionnaires.

FSFI questionnaire consists of 19 items to evaluate female sexual function within a period of four weeks. In this questionnaire, six main domains of sexual function are evaluated, including sexual desire, lubrication, sexual arousal, sexual satisfaction, orgasm and sexual pain (7, 12). Questions are scored based on a Likert scale, and total score of FSFI is obtained by summing up the scores achieved in each domain.

In the present study, cut-off points for FSD were as follows: sexual desire: 3.3, sexual arousal: 3.4, lubrication: 3.7, sexual pain: 3.8, orgasm: 3.4 and sexual satisfaction: 3.8 (9). FSFI has been widely used in clinical and non-clinical settings, and the Persian version of this questionnaire has been validated for the Iranian population (13). Reliability of FSFI was assessed for the entire questionnaire, as well as the items in each domain, using Cronbach’s alpha. Cronbach’s alpha was calculated to be ≤0.70, which was indicative of adequate reliability coefficient. Moreover, sensitivity analysis for the Iranian version of FSFI determined score 28 as the cut-off point (sensitivity: 83%, specificity: 82%). In other words, total score of 9).

Demographic questionnaires were used to collect the following data: age, number of children, duration of relationship with partner, age of partner, menstrual pattern, method of contraception, education level of subject and partner, employment status of partner, presence of diseases, consanguinity with partner, use of medications, family income status and history of sexual abuse.

If participants were not able to read or write, they would be assisted by the researcher to understand and complete the questionnaires via interviews. Women diagnosed with sexual dysfunction at the end of the study were advised to consult a gynecologist.

This study was approved by the Ethics Committee of Sabzevar University of Medical Sciences, Iran.

In this study, data analysis was performed using SPSS V.20 (IBM Inc., Chicago, Il, USA). Study variables including age, income status, employment status and education status were presented as frequency and percentage. Normally distributed data were presented as mean and standard deviation (SD), while median and interquartile range (IQR) were used for data without normal distribution.

Chi-square test was used to evaluate the association between study variables and prevalence of FSD. In addition, general linear model (GLM) was applied to assess the effect of study variables on the total score of FSFI. Also, binary logistic regression was used to evaluate the relationship between total FSFI score and other study parameters.

Initially, univariate analysis was performed to verify the association between study variables and presence of FSFI, and variables with significant correlations were used in multiple regression analysis. Moreover, odds ratio with 95% confidence interval was used to describe the relationship between study parameters. It is noteworthy that subjects with history of sexual abuse were excluded from GLM and regression analysis in order to reduce bias. Confidence limit of this study was set at 0.95, and P-value of less than 0.05 was considered as statistically significant.
Results

In total, 264 women with mean age of 32.2±10.27 years were enrolled in this study (age range: 15-62 years). Natural birth control was the most common method of contraception among these women (31.1%), and 32.2% of the subjects had no children. The majority of participants had regular menstrual cycle (64%), and 7.6% were in menopause. In addition, 6.8% and 2.3% of the studied subjects were undergoing hormone therapy and psycho-therapy, respectively. As for diseases, diabetes mellitus was reported in 2.3% of the subjects, while 3.4% had ovarian cysts, 2.7% had hypertension, and 0.8% of the women were infertile.

Consanguinity was reported in 78 couples (29.5%). With respect to age, only one woman was the same age as her partner, and 96 couples had age difference of less than two years. In terms of education level, more than one third of the participants (34.1%) were below diploma, and 97 women (36.7%) reported the education level of their partners to be below diploma. It is noteworthy that 3% of the study population had history of sexual abuse.

Among the studied subjects, prevalence of sexual dysfunction was estimated at 62.1% (n=164). Sexual dysfunction was observed to be most frequent in domains of sexual desire (49.2%), sexual arousal (43.2%), orgasm (38.6%), lubrication (36%), sexual pain (35.2%) and sexual satisfaction (26.1%), respectively (Figure 1).

Compared to women with normal sexual function, subjects with FSD were significantly older (P<0.001) and had lower education level (P<0.001). Moreover, rate of consanguinity was higher among women with FSD (P=0.005), and partners of these women were reported to have lower education level (P<0.001). Also, use of medications was more prevalent among women with FSD compared to subjects with normal sexual function (P=0.01) (Table 1).

According to other results of this study, number of children was significantly higher in women with FSD (median=2.0, IQR=2.0) compared to those with normal sexual function (median=1.0, IQR=2.0) (P<0.001). Additionally, women with FSD had longer marriages (median=3.0 years, IQR=3.0) compared to normal women (median=2.0 years, IQR=1.0) (P<0.001). Distribution of sexual dysfunction in different domains of FSFI is shown in Table 2.

According to the results of GLM analysis, factors such as employment status of spouse (P=0.03), use of medications (P=0.01) and
 education level of women (P=0.01) had significant effects on FSFI scores. As such, employment status of the spouse and low education level of women significantly reduced total FSFI scores.

Finally, univariate analysis revealed a significant correlation between FSD and variables such as age, personal and spousal education level, number of children, duration of marriage, consanguinity and use of medications. In addition, multiple regression analysis was indicative of a significant correlation between the education level of women and prevalence of FSD (P=0.01) (Table 3).

Discussion

Sexual function was first described in 1960 as a linear model consisting of four phases of excitement, plateau, orgasm and resolution. Later in 2002, non-linear model of sexual response was defined, especially for female gender, encompassing social and psychological aspects (1). 

Sexual health is a complicated term covering a wide range of health aspects. According to the report published by the World Health Organization (WHO) in 2006, sexual health defines not only as the absence of sexually transmitted diseases, but is also related to mental, physical and emotional well-being of an individual. Any malfunction in the aforementioned aspects could lead to sexual dysfunction. Therefore, a respectful approach free of discrimination is needed as to maintain sexual health in a community (14).

According to the results of the present study, FSD has a relatively high prevalence among Iranian women (62.1%). In a large-scale study, highest rate of sexual function problems in all categories was reported in regions of South-east Asia. As such, low sex drive and inability to reach orgasm were the most prevalent domains of sexual dysfunction in these areas (15). In another population-based study in Iran, FSD status was evaluated in three levels of mild (total FSFI score: 18-23), moderate (total FSFI score: 11-17) and severe (total FSFI score: ≤10). According to the findings, 24.9% of the population had moderate or severe sexual dysfunction. Furthermore, 31.5% of the studied women were reported to have disorders in at least one of the domains of FSD (4).

In one study conducted in Turkey, rate of FSD was reported to be 43.4% (total FSFI score: <26) (16). Considering total FSFI score of 9).

In the present study, sexual desire was the most frequent domain of FSD (49.2%). This finding is inconsistent with the results obtained by a similar study in Iran, which reported orgasmic disorders as the most prevalent domain (37%), and sexual desire as the second most common problem among women with FSD (35%). This difference could be due to variations in cut-off points determined for FSD domains. In the current study, we used different cut-off points for each domain, while previous studies determined the cut-off point at 3.9 for all domains, which is higher than the value considered in the present study (4).

In the current study, rate of FSD was observed to increase with age (Figure 2). Common belief suggests that sexual disorders tend to be more prevalent in middle-aged women, as well as those ageing ≥27 years (4, 16-18). Increased prevalence of FSD is mainly associated with age due to decreased sex drive, reduced sexual intercourse and vaginal dryness caused by menopause (i.e., low estrogen secretion) (19).