Design and Data Collection
This study was a cross-sectional study of endometriosis women who attended the Infertility Clinic of Arash Hospital in Tehran in the period from May 2016 to February 2017.
In this period, the total number of currently infertile women (400 women) who underwent diagnostic laparoscopy was selected. Based on laparoscopic findings, we exclude women with abnormalities other than endometriosis. The subjects included 220 infertile women with a laparoscopic and/or histological diagnosis of endometriosis. Endometriosis stage was scored based on the revised classification of the American Fertility Society (20).
Inclusion criteria included age range of 15-45 years, absence of the history of chronic diseases or condition resulting in sexual dysfunction (such as cardiovascular disease, diabetes, hysterectomy, premature ovarian failure etc.), not using any drugs affecting sexual response cycle, married and living with husband, and having sexual intercourse in the past 4 weeks.
Ethics
This study was approved by the ethics committee of Tarbiat Modares University of Medical Sciences (IR.TMU.REC.1395.358). After explaining the study's purposes, written consent and verbal assent was collected from all participants and women were informed that their participation was voluntary, confidential, and anonymous.
Measures
Socio-demographic and anthropometric characteristics including women’ and spouses’ age, age at marriage, BMI, educational level, income, occupational status were collected for all participants. Participants were asked to report their exercise hours/week.
Sexual Function: SF during a four-week period was assessed by the Persian version of the Female Sexual Function Index (FSFI), which has been previously validated by Mohammadi et al. (21). The FSFI is a 19-item questionnaire that includes six main aspects of SFs including sexual desire (two items), arousal (four items), lubrication (four items), orgasm (three items), satisfaction (three items) and pain (three items). The score for all items ranges between 0–5 except for items 1, 2, 15, and 16 (ranging 1–5). The sum score of each domain was multiplied in its certain factor. This factor was 0.6 for desire, 0.3 for arousal and lubrication, and 0.4 for orgasm, satisfaction, and pain. The total score was calculated by adding the six domain scores, which higher scores indicating better SF.
Depression and Anxiety: For detecting and classifying the severity of anxiety and depression, Hospital Anxiety and Depression Scale (HADS) was used. The instrument contains 14 questions and consists of two subscales including anxiety (HADS-A) and depression (HADS-D). Each question was rated on a 4-point Likert-type scale (0=never, 1=seldom, 2=sometimes & 3= always). Total scores less than 8 indicate normal range; scores 8-10 reflect mild alterations and scores more than 11 indicate clinically significant levels of anxiety/depression. The validity and reliability of this questionnaire were confirmed by Montazeri et al. (22).
Pelvic pain and dyspareunia: The intensity of pelvic pain and dyspareunia was measured based on the Visual Analog Scale (VAS). This scale consists of a straight line that ranges from zero (no pain) to ten (the most severe pain possible). Subjects were asked to score their pain severity on a scale from 0 to 10.
Sleep Quality: Multiple aspects of sleep quality during the previous month was assessed using the valid and reliable Persian version of the Pittsburgh Sleep Quality Index (PSQI) (23). This questionnaire contains 19 items in seven domains (sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction) on a scale from 0 to 3; so the total score of PSQI is from 0 to 21. A total score higher than 5 identifies poor sleep quality and scores lower than 5 show absence of sleep disorder.
All participants answered all questionnaires. 11 questionnaires have not been analyzed due to incomplete data. The risk factors of sexual dysfunction were assessed by path analysis.
Statistical analysis:
Data analysis was performed using the SPSS Software (version 21) and LISREL software (version 8.8). Bivariate correlations and descriptive analysis were used to analyze the degree of correlation between the SF of endometriosis women with sleep quality, anxiety, depression, endometriosis stage, the intensity of pelvic pain and dyspareunia.
A path model was used to evaluate the predictive effects of independent variables on SF in women with endometriosis. Path analysis is a kind of multiple regression statistical analysis that is utilized to asses causal models by testing a specific pattern of relationship between some variables. Direct, indirect, and total effects of causal relations between variables were found by path analysis.
We used the lisrel statistical program to fit the path model, which we hypothesized. For evaluation of the model fitness, RMSEA (Root mean square error of approximation), AGFI (adjusted goodness of fit index), CFI (Confirmatory Factor Analytic), and Chi-square/df were used. RMSEA values less than 0.07, Chi-square/df lower than 3, AGFI more than 0.9, and CFI more than 0.95 are indicative of a good fitting model. T-value greater than +2 or less than – 2 were considered statistically significant.