Introduction

The World Health Organization defines sexual health as the state of physical, emotional, mental, and social well-being in relation to sexuality, not merely the absence of disease, dysfunction, or infirmity (1). Sexual response is one element of a woman's sexual health and sexual dysfunction refers to a problem that occurs during any phase of the sexual response cycle (2, 3). Female sexual dysfunction (FSD) is defined as a recurrent or persistent absence of sexual desire and sexual arousal, sense of pain during intercourse, and inability to or persistent difficulty in achieving orgasm (4).

Social and cultural barriers, taboos, and misconceptions make the estimation of sexual dysfunction prevalence in women quite difficult (5). However, based on the results of current studies, sexual problems are highly prevalent in women (6). The results of a global study revealed that 39% of women were affected by at least one sexual dysfunction (7). In a population-based study conducted in Iran, the prevalence of FSD was reported as 31% (8).

Sexual dysfunction is also known as one of the causes of emotional tensions and marital conflicts, which can have devastating effects on the quality of life, self-confidence, mood, and relationships among couples (9). The diagnosis and treatment of sexual dysfunction can play an important role in the enhancement of sexual satisfaction, improvement of quality of life, and also prevention of marital conflicts and their associated consequences (10).

The prevention and treatment of FSD requires the exact estimation of its prevalence in a society. Given the large number of reproductive-age women in the population pyramid of Iran and the importance of sexual function as one of the most important public health issues, the present systematic review was conducted to investigate the prevalence of sexual dysfunction among the reproductive-age women in Iran.

Materials and Methods

The present study was a systematic review and a meta-analysis examining the prevalence of sexual dysfunction among the reproductive-age women in Iran. Databases were searched with no time restriction; in this regard, the articles published up to April 9, 2017 were investigated.

Search Strategy

To find the relevant studies, the databases of SID, IranMedex, Magiran, Irandoc, Scopus, and PubMed, as well as the search engine of Google Scholar were used. The searching process was performed using the following keywords: "Female sexual dysfunction", "Female sexual function", "Sexuality", "Prevalence", "Reproductive age", and "Iran", along with all their possible combinations. To ensure that no article is missed, the reference lists of all included articles were also manually reviewed to identify additional articles.

Inclusion and Exclusion Criteria

The main criterion for the inclusion of the articles in this systematic review was the selection of cross-sectional studies published in Persian or English investigating the prevalence of sexual dysfunction among the Iranian women of reproductive age. Consequently, the studies conducted on pregnant women, infertile individuals, women with known psychiatric disorders, individuals with chronic diseases, and those with gynecologic malignancies were excluded.

In addition, the articles combining the prevalence of sexual dysfunction in women of reproductive age and menopause age were excluded from this systematic review due to the inability to separate the results related to the reproductive age. The other exclusion criteria included the use of researcher-made questionnaires and sample size of less than 100 individuals, as well as lack of access to the full texts of the articles.

Article Selection and Data Extraction

The selection process was performed in three steps. In this regard, first, the titles of all collected articles were reviewed, and duplicates were removed. Second, the abstracts of all articles that were somehow relevant to the subject of interest were collected. Finally, the studies that investigated the prevalence of sexual dysfunction among the Iranian reproductive-age women were included in the study.

Two reviewers independently performed this process, and disagreements between the researchers were resolved through discussion. The data were extracted from the studies meeting the inclusion criteria included the first author’s name, year of research implementation, year of publication, age range and mean age of study participants, sample size, instruments used for assessing sexual function, and prevalence of sexual dysfunction.

Quality Assessment of Articles

The quality of the articles included in this systematic review and meta-analysis was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist (11). This checklist is comprised of 22 assessment items with a score range of 0-44. Accordingly, the articles with the score ranges of 0-22, 23-33, and 34-44 were divided into three groups of low-quality, moderate-quality, and high-quality, respectively.

Statistical Analysis

The data were analyzed using the RevMan5.3 software. The meta-analysis in this study was performed via the Random Effects model. The calculation of the standard error was accomplished using the formula of SEp=sqrt [p(1-p)/n].

Results

The initial search query led to the retrieval of a total of 1,024 articles. After the exclusion of duplicates and irrelevant articles, 17 related articles were remained for full text evaluation. Out of these articles, one, one, two, and four articles were removed due to small sample size, lack of access to the full text, use of researcher-made questionnaires, and impossibility of the separation of the results associated with reproductive-age women, respectively (Figure 1).

Out of the nine articles included in this systematic review, three and two cases had been conducted in the city of Tehran (12, 13, 14) and Sari (15, 16), respectively. The other studies had been carried out in the cities of

Figure 1. PRISMA flow diagram of study selection process

Ilam (17), Tabriz (18), and Dezful (19), as well as in Qazvin, Kermanshah, Golestan, and Hormozgan provinces (20). The articles had been also published between 1999 and 2015, and the total sample size was 4,032 individuals with averagely 448 samples per study. The smallest and largest sample sizes were related to the articles performed by Ramezani et al. (120 individuals) and Hosseini Tabaghdehi et al. (899 individuals), respectively (13, 15).

In the investigations conducted by Shokrollahi et al. (14) and Khaki-Rostami et al. (16), the Brief Sexual Function Index for Women and Arizona Sexual Experiences Scale had been used to assess sexual function in women. The researchers of the other studies had utilized the Female Sexual Function Index (FSFI) (12, 13, 15, 17, 18, 19, 20). Based on the reviewed studies, the overall prevalence of sexual dysfunction among the reproductive-age women in Iran ranged within 22.3% (in the city of Sari) to 66% (in the city of Tabriz) (16, 18).

The prevalence of sexual dysfunction in the domain of sexual desire ranged from 3.6% in the article by Khaki-Rostami et al. to 45.3% in the study by Jaafarpour et al. (16, 17). The lowest (10.9%) and highest (44%) prevalence rates of sexual dysfunction in the domain of sexual arousal were respectively found in the research performed by Amirkhani et al. and Mohammad-Alizadeh-Charandabi et al., respectively, in the city of Tabriz (12, 18).

The lowest (14.3%) and highest (56.1%) prevalence rates of the dimension of sexual pain disorder were observed in the studies by Amirkhani et al. and Ramezani Tehrani et al., respectively (12, 20). Furthermore, the prevalence of sexual lubrication disorder varied from 7.7% in the article conducted by Khaki-Rostami et al. to 41.2% in the investigation carried out by Jaafarpour et al. (16, 17).

The highest prevalence rate of orgasmic disorder (42.7%) was in the study by Hosseini Tabaghdehi et al. conducted in the city of Sari, and the lowest prevalence rate of this disorder (16.7%) was reported in the study by Ramezani et al. in the city of Tehran (15, 13). The prevalence of sexual dissatisfaction in the articles reviewed was between 2.4% in the study by Hosseini Tabaghdehi et al. and 49% in the study carried out by Shokrollahi et al. (15, 14) (Table 1).

Table 1. Characteristics of the included studies

BSFI-W: Brief Sexual Function Index-Women, FSFI: Female sexual function index, FSD: female sexual dysfunction, ASEX: Arizona Sexual Experience Scale

In this study, a meta-analysis was performed on seven articles using the FSFI. The retrieved studies reported no data regarding the prevalence of sexual dysfunction in some dimensions. In this regard, the overall prevalence of sexual dysfunction and the prevalence of orgasmic disorder were reported in six articles. Five studies examined the prevalence of sexual desire disorder, sexual arousal disorder, and sexual pain disorder. Additionally, the prevalence of sexual lubrication disorder was dealt with in four manuscripts.

The overall prevalence of sexual dysfunction in reproductive-age women was estimated as 52% (95% CI: 39-66%) (Figure 2). The prevalence rates of sexual dysfunction in the dimensions of sexual desire, sexual arousal, sexual lubrication, sexual pain, and orgasmic disorder were obtained as 39% (95% CI: 35-42%), 34% (95% CI: 21-46%),32% (95% CI: 21-43%), 38% (95% CI: 24-51%), and 30% (95% CI: 32-38%), respectively (Figure 3).

Figure 2. Forest plot of the prevalence of sexual dysfunction among reproductive-age women in Iran

Figure 3. Forest plot of the prevalence of sexual dysfunction domains among reproductive-age women in Iran

Table 2. Assessment of the quality of reviewed studies according to STROBE criteria

1, title, and abstract; 2, background/rationale; 3, objectives; 4, study design; 5, setting; 6, participants; 7, variables; 8, data sources/ measurement; 9, bias; 10, study size; 11, quantitative variables; 12, statistical methods; 13, participants (groups); 14, descriptive data; 15, outcome data; 16, main results; 17, other analyses, discussion; 18, key results; 19, limitations; 20, interpretation; 21, generalizability, other information; 22, funding

2(□), good description; 1(◇), partial description; 0(ϴ), no description