Methods
This systematic and meta-analysis was conducted to determine the social intermediate factors of health associated with sexual quality of life in women of reproductive age.
The model used to write this systematic review study was world health organization’s model of social determinants of health [ 11 ].
Search was done in six databases of PubMed/Medline (NLM), Embase, Web of Science, Scopus, ProQuest, and CENTRAL from 2010 to 2022 with no language constraints systematically. For non-English papers, translation to English was done. The keywords of the two main components of “sexual quality of life” and “health social intermediate factors” were found through Mesh system in PubMed and Emtree in Embase database along with suitable synonyms. Through AND and OR operators, these words were merged with each other, and the search syntax was first prepared for PubMed. Next, this syntax was adapted for other databases. In addition, manual search of the included studies was done to find similar studies (Additional file 1 ).
The primary aim of this study was to determine the social intermediate factors associated with women’s sexual quality of life. Accordingly, observational studies (cohort, case-control, and cross-sectional) were included. Qualitative studies, clinical trials, theses, posters, letters to editor, systematic review and meta-analyses studies were excluded. The studied population consisted of women of reproductive age (18-45 years), non-pregnant or at least 1 year past their pregnancy, no chronic disease (hypertension, diabetes, cardiovascular disease, asthma, kidney diseases, …), and different types of cancer. The sexual quality of life, as the main variable of the study, has been evaluated using Symonds women’s sexual quality of life scale (SQOL-F). The health social determinants intermediate factors based on WHO model [ 11 ] were considered as exposure variables including lifestyle, depression, anxiety, stress, social support, physical activity, self-esteem, body image, violence, high-risk behaviors, access to healthcare services, sexual function, and quality of marital relation. Assessment of intermediate factors was done using the following questionnaires: Miller-Smith lifestyle questionnaire (LSQ), beck depression inventory (BDI), hospital anxiety and depression scale (HADS) for anxiety and depression variables, Cohen’s perceived stress (PSS-14), perceived social support questionnaire Zimet (MPSS), Rosenberg self-esteem scale, body image scale (BIS) or female genital self-image scale (FGSIS-I), domestic violence or sexual violence, female sexual function index (FSFI), marital intimacy needs questionnaire (MINQ) or dyadic adjustment scale (DAS), high-risk behaviors (cigarette smoking, alcohol and tobacco consumption), physical activity and access to healthcare services through demographic questionnaire was captured through yes/no question. The secondary aim in this study was to determine any possible relationship between duration of marriage and sexual quality of life.
The data of included studies were extracted by two independent persons through a researcher-made checklist according to the study aims. This information included author’s name, year of publication, place of study, mean score of sexual quality of life, effect size, sample size, mean age of subjects, type of study (cross-sectional, cohort, case-control), sampling method (random or nonrandomized), measured variables, utilized instruments, and quality assessment score of the primary studies.
R software (Version R-4.2.1) along with Metacore function belonging to meta package (Version 5.5-0) were used for meta-analysis. Correlation coefficients were converted to Z fisher scores and then merged. These values were calculated through the Metacore function. Considering the expected diversity in primary studies, Random model and inverse variance type were used. To indicate the results, forest plot was used with confidence interval 95%. I 2 index and chi 2 test were used for assessing the heterogeneity of studies. Accordingly, I 2 lower than 25% functioned as low heterogeneity, 25-50% as moderate, 50-75% as high, and more than 75% as very severe heterogeneity (considerable heterogeneity) [ 19 ]. Subgroup analysis method was used for finding possible sources of heterogeneity in cases of I 2 above 75%. Correlation coefficient with 95% confidence interval was used for determining the relationship of social intermediate factors and sexual quality of life with interpretive level, defined as 0.1-0.29 weak level, 0.30-0.49 moderate level, and 0.50 and above as strong level [ 20 ]. Begg & Egger tests were used for assessing publication bias of studies through metabias function belonging to meta package. In all analyses, significance level was considered p < 0.05. However, for Begg & Egger tests, due to the limited number of studies, significance level was considered p < 0.10. Sensitivity analysis was done to assess the effect of each study on the overall outcome using one-out remove approach, and it was calculated through metanif function from meta package.
Two persons (M.B, Z.M) independently evaluated the primary studies in terms of methodological quality using Newcastle-Ottawa instrument. It is a specific tool for measuring the quality of observational studies. Studies based on this instrument are examined in terms of quality of study design, data collection method, sample registration process, response rate, generalizability of results, and statistical analyses. For cohort, case-control, and cross-sectional studies, this instrument has a specific version. The scoring of the items of this instrument can be as no star (score 0), one star (score 1), and two stars (score 2). The maximum score would be 10 stars, where studies with six stars (score) and above were considered as those with a high methodological quality (Additional file 2 ) [ 21 ]. In assessing the quality of studies, screening and extraction of data were done by two independent persons. In cases of disagreements, two researchers discussed, resolved disagreements, and created a one-sheet report of findings at a meeting.
Results
In response to the search across databases of PubMed = 1259, Scopus = 1877, Embase = 1358, Web of Science = 1394, Cochrane = 299, and ProQuest = 205, overall 6392 papers were found and inputted into EndNote software. After removing duplicates, 4543 studies were investigated by two independent persons in two separate stages. The first stage involved examining the title and abstract of studies, based on which 4476 studies that did not meet the inclusion criteria and were excluded. Regarding the remaining 67 studies, their full text was re-examined in terms of inclusion and exclusion criteria. After the second stage, eventually 15 studies met the inclusion criteria to be included in this systematic review and meta-analysis, based on which data extraction was done (Fig. 1 ). Fig. 1 Flowchart of study
Flowchart of study
The included studies had sample sizes of at least 88 and at most 800 subjects. The total sum of all study samples was 3878. The overall mean age of the women based on included studies was 33.6 ± 3.4 years, and the overall mean score of the sexual quality of life was 71.11 ± 8.7. Regarding design of conducting primary studies, two had been done as case-control [ 22 , 23 ], one as cohort [ 24 ], and 12 as cross-sectional [ 25 – 36 ]. From among the cross-sectional ones, only six of them had random sampling method [ 25 , 29 – 32 , 34 ]. In the included studies, 7 have been conducted in Iran, 6 in Turkey, 1in Spain and 1 study in France. The full text of a study was in Persian [ 27 ], one in Turkish [ 29 ], and other in English. Methodological quality assessment of studies based on Newcastle-Ottawa scale was high in five studies (score above 6) [ 25 , 26 , 31 – 33 ] (Table 1 and Additional file 2 ). Table 1 Characteristics of included studies Author, Year/ Country of study Design study Sample size Mean of age Mean of SQOL a Controlled variables and types of tools used Type of analysis Main result (Variables related to the quality of sexual life) Quality assessment score (NOS b ) Sheikhan et al., 2019/ Iran [ 25 ] Cross-sectional (random) 800 – – Demographic: age, education, age at marriage, age at monarch, duration of marriage, age at first pregnancy, having private bedroom, smoking and addicted at spouse, drinking alcohol Stress (stress perceived Cohen), Sexual violence (self-designed), Sexual quality of life (SQOL-F) Bivariate analysis Sexual violence: r = −0.502, P = - Stress: r = − 0.228, P = - Alcohol used:- Duration of marriage:- 8 Eftekhar et al., 2019/ Iran [ 22 ] Case-control 150 (50 case, 100 control) 37.8 ± 9.4 79.5 ± 20.6 Demographic: age, education, duration of marriage, body mass index (BMI) Sexual function (Female Sexual Function Index (FSFI)), Sexual quality of life (SQOL-F), Female genital self-image (Female genital self-image scale (FGSIS-I)) Multivariate analysis Sexual function: r = 0.543 Female Genital Self-Image: r = 0.121 Duration of marriage: r = 0.187 5 Türkben Polat and Kaplan Serin, 2021/ Turkey [ 26 ] Cross-sectional (nonrandom) 90 32.9 ± 7.7 50.4 ± 10.2 Demographic: age, education, duration of marriage, parity, Body mass index (BMI), occupation, income, family planning, smoking, alcohol used, weight satisfaction, physical activity, efforts to lose weight, meditation Self-esteem (Rosenberg self-esteem scale), Sexual quality of life (SQOL-F) Bivariate analysis Self-esteem: r = 0.286, P < 0.01 Smoking:- Alcohol used:- Physical activity: r = 0.236 Duration of marriage: r = − 0.061 6 Samimi et al., 2016/ Iran [ 27 ] Cross-sectional (nonrandom) 121 32.4 + 7.5 80.1 ± 19.7 Demographic: age, number of members Family, education, education of spouse, age of spouse, duration of marriage Variables related to health: quantity and quality of sleep, Body mass index (BMI), physical activity Factors related to work: Work, type of work system, having a second job, overtime, hours work per week, type of work activity, occupational accidents Sexual quality of life (SQOL-F) Bivariate analysis Physical activity: r = 0.195 Duration of marriage: r = −0.381 4 Tugut et al., 2021/ Turkey [ 28 ] Cross-sectional (nonrandom) 100 38.7 ± 8.9 76.8 ± 15.3 Demographic: age, education, occupation, income, family type, number of children, place of residence, social support from spouse and support from other family members, economic status, average length of marriage Depression (Beck Depression Inventory (BDI)), General health (GH-28), Sexual quality of life (SQOL-F) Bivariate analysis Depression: r = −0.52, P = 0.00 General health: r = − 0.47, P = 0.00 Duration of marriage: - 4 Tav et al., 2018/ Turkey [ 29 ] Cross-sectional (random) 162 38.8 ± 5.4 – Demographic: age, place of residence, education, income, age at marriage, Work Dyadic adjustment (dyadic adjustment scale (DAS)), Violence, Sexual quality of life (SQOL-F) Bivariate analysis Dyadic adjustment: r = 0.576, p < 0.001 Violence:- 5 Taskin Yilmaz et al., 2019/ Turkey [ 30 ] Cross-sectional (random) 538 35.5 ± 8.7 83.3 ± 16.4 Demographic: body weight preference, body weight perception, healthy nutritional status, exercise, general health perception Body Image (BIS), Sexual quality of life (SQOL-F) Bivariate analysis Body image: r = 0.381, P = 0.00 Exercise: - 4 Shahraki et al., 2018/ Iran [ 31 ] Cross-sectional (random) 264 32.9 ± 7.2 84.8 ± 18.9 Demographic: age, partner age, duration of marriage, pervious abortion Depression (Beck Depression Inventory (BDI)), Sexual function (Female Sexual Function Index (FSFI)), Sexual quality of life (SQOL-F) Multivariate analysis Sexual function: r = 0.59, P < 0.001 Depression: r = − 0.49, P < 0.001 Duration of marriage: r = − 0.03 6 Haghi et al., 2018/ Iran [ 32 ] Cross-sectional (random) 475 – – Demographic: age, weight, height, age of husband, duration of marriage, living with husband’s family, the history of boyfriend, relationship before marriage, job, working in night shifts, education, income Perceived sexual characteristics (self-designed), Sexual behavior variables (self-designed), Sexual function (Female Sexual Function Index (FSFI)), Marital intimacy (Marital Intimacy Needs Questionnaire (MINQ)), Sexual quality of life (SQOL-F) Bivariate analysis Sexual function: r = 0.39, P < 0.001 Marital intimacy: r = 0.350, P < 0.001 7 Velayati et al., 2021/ Iran [ 33 ] Cross-sectional (nonrandom) 236 27.9 ± 5.7 56.8 ± 20.2 Demographic: age, education, occupation, income, house status, age of husband, Husband’s education, information source, having child Self-esteem (Rosenberg self-esteem scale), Depression and anxiety (Hospital Anxiety and Depression Scale (HADS)), Sexual quality of life (SQOL-F) Bivariate analysis Self-esteem: r = 0.54, P < 0.001 Anxiety: r = − 0.48,P < 0.001 Depression: r = − 0.47, P < 0.001 7 Panahi et al.,2021/ Iran [ 34 ] Cross-sectional (random) 420 33.1 ± 4.6 59.7 ± 19.2 Demographic: age, education, employment status, age of first child, age of spouse, spouse’s educational, duration of marriage, age at marriage, number of weekly sexual intercourses, use of contraceptives Sexual function (Female Sexual Function Index (FSFI)), Sexual quality of life (SQOL-F) Multivariate analysis Sexual function: r = 0.306 Duration of marriage: r = 0.101 5 Alcalde et al., 2021/ Spain [ 35 ] Cross-sectional (nonrandom) 173 37.8 ± 5.4 80.2 ± 4.3 Demographic: age, education, Body mass index (BMI), age of spouse, spouse’s educational, heavy menstrual bleeding, dysmenorrhea, dyspareunia Dyadic adjustment (dyadic adjustment scale (DAS)), Sexual quality of life (SQOL-F) Bivariate analysis Dyadic adjustment: r = 0.008 5 Yuksekol et al., 2021/ Turkey [ 36 ] Cross-sectional (nonrandom) 135 31.2 ± 5.9 65.6 ± 26.8 Demographic: Age, education, age at monarch, duration of marriage, income, work, living place, family type, duration of infertility, vaccination Female genital self-image (Female Genital Self-Image Scale (FGSIS)), Dyadic adjustment (dyadic adjustment scale (DAS)), Sexual quality of life (SQOL-F) Bivariate analysis Female genital self-image: r = 0.618, P = 0.00 Dyadic adjustment: r = 0.542, P = 0.00 Duration of marriage: r = 0.934. P = 0.007 5 Brunault et al., 2015/ France [ 24 ] Cohort 126 – – Demographic: age, marital status, previous maximal body mass index (BMI), current BMI, history of previous bariatric surgery Binge eating severity (using the Bulimic Investigatory Test, Edinburgh = BITE) Depression (Beck Depression Inventory (BDI)), Sexual quality of life (SQOL-F) Bivariate analysis Depression: r = − 0.60, P < 0.01 Binge eating severity: r = − 0.47, P < 0.01 4 Telli et al., 2020/ Turkey [ 23 ] Case-control 176 (88 case, 88 control) 35.7 ± 6.2 80.1 ± 21.4 Demographic: Age, education, income, Employment status, Child presence Dyadic adjustment (dyadic adjustment scale (DAS)), Sexual quality of life (SQOL-F) Bivariate analysis Result on Control group (health) Dyadic adjustment: r = 0.500, P < 0.01 4 a Sexual quality of life b Newcastle-Ottawa Scale r = Correlation coefficient with 95% confidence interval
Characteristics of included studies
Demographic: age, education, age at marriage, age at monarch, duration of marriage, age at first pregnancy, having private bedroom, smoking and addicted at spouse, drinking alcohol
Stress (stress perceived Cohen), Sexual violence (self-designed), Sexual quality of life (SQOL-F)
Sexual violence:
r = −0.502, P = -
Stress:
r = − 0.228, P = -
Alcohol used:-
Duration of marriage:-
Demographic: age, education, duration of marriage, body mass index (BMI)
Sexual function (Female Sexual Function Index (FSFI)), Sexual quality of life (SQOL-F), Female genital self-image (Female genital self-image scale (FGSIS-I))
Sexual function:
r = 0.543
Female Genital Self-Image:
r = 0.121
Duration of marriage:
r = 0.187
Demographic: age, education, duration of marriage, parity, Body mass index (BMI), occupation, income, family planning, smoking, alcohol used, weight satisfaction, physical activity, efforts to lose weight, meditation
Self-esteem (Rosenberg self-esteem scale), Sexual quality of life (SQOL-F)
Self-esteem:
r = 0.286, P < 0.01
Smoking:-
Alcohol used:-
Physical activity:
r = 0.236
Duration of marriage:
r = − 0.061
Demographic: age, number of members Family, education, education of spouse, age of spouse, duration of marriage
Variables related to health: quantity and quality of sleep, Body mass index (BMI), physical activity Factors related to work: Work, type of work system, having a second job, overtime, hours work per week, type of work activity, occupational accidents
Sexual quality of life (SQOL-F)
Physical activity:
r = 0.195
Duration of marriage:
r = −0.381
Demographic: age, education, occupation, income, family type, number of children, place of residence, social support from spouse and support from other family members, economic status, average length of marriage
Depression (Beck Depression Inventory (BDI)), General health (GH-28), Sexual quality of life (SQOL-F)
Depression: r = −0.52, P = 0.00
General health: r = − 0.47, P = 0.00
Duration of marriage: -
Demographic: age, place of residence, education, income, age at marriage, Work
Dyadic adjustment (dyadic adjustment scale (DAS)), Violence, Sexual quality of life (SQOL-F)
Dyadic adjustment:
r = 0.576, p < 0.001
Violence:-
Demographic: body weight preference, body weight perception, healthy nutritional status, exercise, general health perception
Body Image (BIS), Sexual quality of life (SQOL-F)
Body image:
r = 0.381, P = 0.00
Exercise:
-
Demographic: age, partner age, duration of marriage, pervious abortion
Depression (Beck Depression Inventory (BDI)), Sexual function (Female Sexual Function Index (FSFI)), Sexual quality of life (SQOL-F)
Sexual function: r = 0.59, P < 0.001 Depression:
r = − 0.49, P < 0.001
Duration of marriage:
r = − 0.03
Demographic: age, weight, height, age of husband, duration of marriage, living with husband’s family, the history of boyfriend, relationship before marriage, job, working in night shifts, education, income
Perceived sexual characteristics (self-designed), Sexual behavior variables (self-designed), Sexual function (Female Sexual Function Index (FSFI)), Marital intimacy (Marital Intimacy Needs Questionnaire (MINQ)), Sexual quality of life (SQOL-F)
Sexual function:
r = 0.39, P < 0.001
Marital intimacy:
r = 0.350, P < 0.001
Demographic: age, education, occupation, income, house status, age of husband, Husband’s education, information source, having child
Self-esteem (Rosenberg self-esteem scale), Depression and anxiety (Hospital Anxiety and Depression Scale (HADS)), Sexual quality of life (SQOL-F)
Self-esteem:
r = 0.54, P < 0.001
Anxiety:
r = − 0.48,P < 0.001
Depression:
r = − 0.47, P < 0.001
Demographic: age, education, employment status, age of first child, age of spouse, spouse’s educational, duration of marriage, age at marriage, number of weekly sexual intercourses, use of contraceptives
Sexual function (Female Sexual Function Index (FSFI)), Sexual quality of life (SQOL-F)
Sexual function:
r = 0.306
Duration of marriage:
r = 0.101
Demographic: age, education, Body mass index (BMI), age of spouse, spouse’s educational, heavy menstrual bleeding, dysmenorrhea, dyspareunia
Dyadic adjustment (dyadic adjustment scale (DAS)), Sexual quality of life (SQOL-F)
Dyadic adjustment:
r = 0.008
Demographic: Age, education, age at monarch, duration of marriage, income, work, living place, family type, duration of infertility, vaccination
Female genital self-image (Female Genital Self-Image Scale (FGSIS)), Dyadic adjustment (dyadic adjustment scale (DAS)), Sexual quality of life (SQOL-F)
Female genital self-image:
r = 0.618, P = 0.00
Dyadic adjustment:
r = 0.542, P = 0.00
Duration of marriage:
r = 0.934. P = 0.007
Demographic: age, marital status, previous maximal body mass index (BMI), current BMI, history of previous bariatric surgery Binge eating severity (using the Bulimic Investigatory Test, Edinburgh = BITE)
Depression (Beck Depression Inventory (BDI)), Sexual quality of life (SQOL-F)
Depression:
r = − 0.60, P < 0.01
Binge eating severity:
r = − 0.47, P < 0.01
Demographic: Age, education, income, Employment status, Child presence
Dyadic adjustment (dyadic adjustment scale (DAS)), Sexual quality of life (SQOL-F)
Result on Control group (health)
Dyadic adjustment:
r = 0.500, P < 0.01
a Sexual quality of life
b Newcastle-Ottawa Scale
r = Correlation coefficient with 95% confidence interval
The results of meta-analysis on variable of depression as one of the health social intermediate determinants with four studies [ 24 , 28 , 31 , 33 ] showed an almost strong and negative relationship with sexual quality of life ( r = − 0.51; CI95% = − 0.56 to − 0.45; chi 2 = 2.94; I 2 = 0%; P = 0.40). The confidence interval for this correlation ranged from moderate to strong with low heterogeneity (Fig. 2 ). Begg test with P = 0.734, Z = -0.34, and Egger with t = − 1.39, P = 0.298 indicated that the publication bias had no effect on the outcome obtained in this section. Sensitivity analysis on the relationship between variable of depression and sexual quality of life showed that elimination of any single study did not have a considerable effect on the outcome obtained from combining all studies (Table 2 ). Fig. 2 Forest Plot correlation coefficient with 95% confidence interval between depression and quality of sexual life Table 2 Summary of sensitivity analysis on the variables related to the sexual quality of life Omitted study Correlation Coefficient Confidence interval Heterogeneity index chi 2 test ( P -value) I 2 Quality of marital relation and quality of sexual life Yuksekol et al.;2021 [ 36 ] 0.37 0.11 to 0.58 0.006 92.1% Haghi et al.;2018 [ 32 ] 0.42 0.15 to 0.63 0.003 93.1% Tav et al.;2018 [ 29 ] 0.36 0.11 to 0.56 0.005 90.7% Telli et al.;2020 [ 23 ] 0.39 0.11 to 0.60 0.005 93.0% Alcalde et al.;2021 [ 35 ] 0.49 0.37 to 0.59 < 0.001 78.1% All studies (without removing any study) 0.41 0.20 to 0.58 0.000 91.0% Body image and quality of sexual life Eftekhar et al.;2019 [ 22 ] 0.50 0.23 to 0.69 0.0006 90.8% Taskin Yilmaz et al.;2019 [ 30 ] 0.40 −0.16 to 0.76 0.160 96.1% Yuksekol et al.;2021 [ 36 ] 0.26 −0.004 to 0.49 0.053 89.4% All studies (without removing any study) 0.39 0.08 to 0.63 0.015 92.2% Sexual function and quality of sexual life Eftekhar et al.;2019 [ 22 ] 0.43 0.25 to 0.56 < 0.0001 90.9% Shahraki et al.;2018 [ 31 ] 0.40 0.36 to 0.52 < 0.0001 79.4% Haghi et al.;2018 [ 32 ] 0.48 0.43 to 0.60 < 0.0001 91.7% Panahi et al.;2021 [ 34 ] 0.50 0.37 to 0.62 < 0.0001 85.5% All studies (without removing any study) 0.45 0.32 to 0.58 < 0.0001 85.5% Depression and quality of sexual life Tugut et al.;2021 [ 28 ] −0.50 −0.569 to − 0.44 < 0.0001 31.3% Velayati et al.;2021 [ 33 ] −0.52 − 0.59 to − 0.45 < 0.0001 3.8% Shahraki et al.;2018 [ 31 ] − 0.52 − 0.60 to − 0.43 < 0.0001 25.9% Brunault et al.;2015 [ 24 ] − 0.48 − 0.54 to − 0.42 < 0.0001 0.0% All studies (without removing any study) − 0.51 − 0.56 to − 0.46 0.40 0.0% Secondary aim (Duration of marriage and sexual quality of life) Eftekhar et al.;2019 [ 22 ] 0.25 − 0.43 to 0.57 < 0.01 99% Yuksekol et al.;2021 [ 36 ] 0.31 −0.22 to 0.69 < 0.01 86% Shahraki et al.;2018 [ 31 ] 0.29 −0.38 to 0.77 < 0.01 99% Turkben Polat and Kaplan et al.;2021 [ 26 ] 0.30 −0.37 to 0.77 < 0.01 99% Samimian et al.; 2016 0.36 −0.26 to 0.77 < 0.01 99% Panahi et al.;2021 [ 34 ] 0.27 −0.41 to 0.76 < 0.01 99% All studies (without removing any study) 0.24 −0.33 to 0.68 < 0.01 99%
Forest Plot correlation coefficient with 95% confidence interval between depression and quality of sexual life
Summary of sensitivity analysis on the variables related to the sexual quality of life
Meta-analysis of the sexual function variable out of health social intermediate factors with sexual quality of life with four studies [ 22 , 31 , 32 , 34 ] showed a moderate and positive relationship with confidence interval ranging from moderate to strong ( r = 0.46; CI95% = 0.32 to 0.58; chi 2 = 25.93; I 2 = 88%; P < 0.01) (Fig. 3 ). Considering very severe heterogeneity (I 2 = 88%) in this section, to identify the possible factors affecting this heterogeneity, subgroup analysis was done. From among the controlled factors, the sample size variable had a greater impact compared to others on reducing the heterogeneity index (average 65.5%) with p < 0.01 (Table 3 and Additional file 3 (fig. S1-S4)). Accordingly, in studies with smaller sample size, a stronger correlation and reduction of heterogeneity were observed compared to overall combination of studies. The results of Begg (Z = 0.34, P = 0.734) and Egger (t = 1.60, P = 0.249) tests did not show considerable publication bias against the obtained outcome. The results of sensitivity analysis in this section showed that removal of each single study did not have a considerable effect on the outcome obtained from combining all studies (Table 2 ). Fig. 3 Forest Plot correlation coefficient with 95% confidence interval between sexual function and quality of sexual life Table 3 Subgroup analysis for sexual function relationship and quality of sexual life Subgroup variables Number Correlation coefficient Confidence Interval chi 2 test (hetrogeneity p -value) I 2 Test for interaction ( P -value) Sample size > = 400 2 0.35 0.51 to 0.63 0.18 45% < 0.01 = 6 (High quality) 2 0.49 0.27 to 0.67 < 0.01 92% 0.67 < 6 (low quality) 2 0.43 0.17 to 0.63 < 0.01 90% Study design Cross-sectional study 3 0.43 0.25 to 0.59 < 0.01 91% 0.98 Case control study 1 0.54 0.42 to 0.68 – – Type of analysis Bivariate analysis 1 0.39 0.31 to 0.46 – – Multivariate analysis 3 0.49 0.30 to 0.64 < 0.01 92% 0.32 All study 4 0.46 0.32 to 0.58 < 0.01 88% –
Forest Plot correlation coefficient with 95% confidence interval between sexual function and quality of sexual life
Subgroup analysis for sexual function relationship and quality of sexual life
Meta-analysis on three studies [ 22 , 30 , 36 ] between the body image variable from among the health social intermediate factors and sexual quality of life showed a moderate positive relationship and confidence interval from very weak to strong and very severe heterogeneity ( r = 0.39; CI95% = 0.08 to 0.63; chi 2 = 25; I 2 = 92%; P < 0.01) (Fig. 4 ). Due to limited number of studies, it was not possible to identify possible source of heterogeneity in this section. The results of Begg (Z = 0.0, P = 1.0) and Egger (t = 0.10, P = 0.939) tests did not show considerable publication bias on the obtained result. The results of sensitivity analysis also showed that removal of each single study did not have considerable effect on the outcome obtained from combining all studies (Table 2 ). Fig. 4 Forest Plot correlation coefficient with 95% confidence interval between body image and quality of sexual life
Forest Plot correlation coefficient with 95% confidence interval between body image and quality of sexual life
Meta-analysis for the relationship between self-esteem variable from among health social intermediate factors with two studies [ 26 , 33 ] revealed a positive moderate relationship with confidence interval of weak to strong and very severe heterogeneity with sexual quality of life ( r = 0.43; CI95% = 0.16 to 0.64; chi 2 = 6.09; I 2 = 84%; P = 0.01) (Fig. 5 ). Due to limited number of studies, it was not possible to evaluate the publication bias or do sensitivity analysis. Fig. 5 Forest Plot correlation coefficient with 95% confidence interval between self-esteem and quality of sexual life
Forest Plot correlation coefficient with 95% confidence interval between self-esteem and quality of sexual life
Meta-analysis on the variable of physical activity from among the health social intermediate factors with two studies [ 26 , 27 ] revealed a very weak positive relationship with confidence interval ranging from very weak to moderate with sexual quality of life (r = 0.21; CI95% = 0.08 to 0.34; chi 2 = 0.09; I 2 = 0%; P = 0.76) (Fig. 6 ). Due to limited number of studies, it was not possible to evaluate the publication bias or do sensitivity analysis. Fig. 6 Forest Plot correlation coefficient with 95% confidence interval between physical activity and quality of sexual life
Forest Plot correlation coefficient with 95% confidence interval between physical activity and quality of sexual life
Meta-analysis of the variable of quality of marital relation from among the health social intermediate variables with five studies [ 23 , 29 , 32 , 35 , 36 ] showed a moderate positive relationship with confidence interval ranging from weak to strong with sexual quality of life (r = 0.41; CI95% = 0.20 to 0.58; chi 2 = 25; I 2 = 91%; P < 0.01) (Fig. 7 ). Considering the value of I 2 = 91% (very severe heterogeneity), subgroup analysis was done. The results revealed that none of the variables of sample size ( P = 0.62), type of instrument ( 000000000 0.58), quality assessment score ( P = 0.76), and type of study design ( P = 0.44) justified the creation of heterogeneity in the relationship between inter-couple relationships and sexual quality of life (Table 4 and Additional file 3 (fig. S5-S8)). The results of Begg (Z = 0.24, P = 0.806) and Egger (t = 0.51, P = 0.642) did not show considerable publication bias on the results obtained in this section. The results of sensitivity analysis showed that removal of every single study did not have a considerable impact on the outcome obtained from combining all studies (Table 2 ). Fig. 7 Forest Plot correlation coefficient with 95% confidence interval between quality of marital relation and quality of sexual life Table 4 Subgroup analysis for quality of marital relation and quality of sexual life Subgroup variables Number Correlation coefficient Confidence Interval chi 2 test (hetrogeneity p -value) I 2 ( p -value) test for interaction Type of scale Dyadic Adjustment Scale 4 0.42 0.15 to 0.64 = 6 1 0.35 0.27 to 0.43 – – 0.58 < 6 4 0.42 0.15 to 0.64 < 0.01 93% Study design Crossectional study 4 0.39 0.12 to 0.60 = 150 2 0.47 0.22 to 0.66 < 0.01 90% 0.62 < 150 3 0.37 0.01 to 0.64 < 0.01 94% All study 5 0.41 0.20 to 0.58 < 0.01 91% –
Forest Plot correlation coefficient with 95% confidence interval between quality of marital relation and quality of sexual life
Subgroup analysis for quality of marital relation and quality of sexual life
Considering other intermediate variables of health social determinants, high-risk behavior (consumption of cigarette, alcohol, drugs of abuse) in two studies [ 25 , 26 ], anxiety one study [ 33 ], stress one study [ 25 ], and variable of violence in two studies [ 25 , 29 ] had a relationship with sexual quality of life. In the variables of high-risk behaviors and violence, in spite of two studies, it was not possible to calculate correlation coefficient for meta-analysis. Again, no study was found on the relationship between social support, access to healthcare services, and lifestyle variables from among the intermediate factors and sexual quality of life based on the search or inclusion/exclusion criteria (Table 1 ).
Meta-analysis of the relationship between duration of marriage and sexual quality of life as the secondary study aim, based on six studies [ 22 , 26 , 27 , 31 , 34 , 36 ], showed that there was no significant relationship between duration of marriage and sexual quality of life ( r = 0.24; CI95% = − 0.33 to 0.68; chi 2 = 359.28; I 2 = 99%; P < 0.01) (Fig. 8 ). Considering the very severe heterogeneity (I 2 = 99%) in this section, to identify the possible factors contributing to heterogeneity, subgroup analysis was done. The results indicated that none of the variables of sample size ( P = 0.50), type of analysis ( P = 0.61), quality assessment score ( P = 0.34), and type of study design ( P = 0.85) justified creation of heterogeneity in the association between duration of marriage and sexual quality of life (Table 5 and Additional file 3 (fig. S9-S12)). The results of Begg (Z = 0.0, P = 1.0) and Egger (t = 0.38, P = 0.726) tests did not show considerable publication bias on the result obtained in this section. The result obtained from sensitivity analysis showed that removal of every single study did not considerable effect on the outcome resulting from combining all studies (Table 2 ). Fig. 8 Forest Plot correlation coefficient with 95% confidence interval between duration of marriage and quality of sexual life Table 5 Subgroup analysis for duration of marriage and quality of sexual life Subgroup variables Number Correlation coefficient Confidence Interval chi 2 test (hetrogeneity p -value) I 2 Test for interaction ( P -value) Sample size > = 250 2 0.04 −0.09 to 0.17 0.09 64% 0.50 < 250 4 0.34 −0.50 to 0.85 = 6 (High quality) 2 −0.04 −0.14 to 0.07 0.80 0% 0.34 < 6 (low quality) 4 0.37 −0.45 to 0.86 < 0.01 99% Design Cross-sectional study 5 0.25 −0.43 to 0.75 < 0.01 99% 0.85 Case control study 1 0.19 0.03 to 0.33 – – Type of analysis Bivariate analysis 3 0.39 −0.70 to 0.93 < 0.01 99% 0.61 Multivariate analysis 3 0.08 −0.04 to 0.19 0.07 62% All study 6 0.24 −0.33 to 0.68 < 0.01 99% –
Forest Plot correlation coefficient with 95% confidence interval between duration of marriage and quality of sexual life
Subgroup analysis for duration of marriage and quality of sexual life