Meta-analysis Of Sex Differences Research Articles

Sex Differences in the Global Prevalence of Nonsuicidal Self-Injury in Adolescents

Nonsuicidal self-injury (NSSI) is a strong predictor of suicide attempts. The prevalence of NSSI has been increasing among female adolescents in North America and Europe, but less is known about trends in other geographical regions. To examine sex differences in the prevalence of NSSI among adolescents within and between geographical regions. MEDLINE and PsycINFO were searched using the keywords adolescents, self-injury, sex factors, and synonyms for articles published in English between January 1, 2000, and May 10, 2022. Studies were included if they presented original data (any study design), included adolescents aged 10 to 19 years, reported results stratified by sex, and explicitly defined self-injury as behaviors occurring without suicidal intent. This meta-analysis was registered with PROSPERO and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Articles were assessed for quality by 2 independent coders (F.M. and J.A.). A random-effects model was used to calculate prevalence. Data were analyzed from July 2022 to April 2023. The prevalence of NSSI in male and female adolescents within and between regions was the main outcome. Odds ratios (OR) with 95% CIs were calculated for community samples. Eight hundred and two studies were screened, and 38 were included (266 491 participants). Across 17 countries, the pooled prevalence of NSSI was 17.7% (female:male OR, 1.60; 95% CI, 1.29-1.98). NSSI was twice as prevalent among female adolescents compared with male adolescents in North America (OR, 2.49; 95% CI, 2.16-2.86) and Europe (OR, 2.08; 95% CI, 1.69-2.58), but not in Asia (OR, 1.00; 95% CI, 0.71-1.41). In this meta-analysis of sex differences in global prevalence of NSSI, the female predominance of NSSI observed among adolescents in North America and Europe aligned with rising rates of suicide in these populations. The comparable prevalence of NSSI among male and female adolescents in Asia also aligned with the lower male-to-female suicide ratio compared with other countries. More research is needed to characterize regional (and potentially cultural) sex differences among adolescents with NSSI to prevent and treat the behavior and to understand the possible interplay with corresponding regional trends in suicide.

A systematic review and meta-analysis of sex differences in clinical outcomes of hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is recognized as the most prevalent form of genetic cardiomyopathy, and recent investigations have shed light on the existence of sex disparities in terms of clinical presentation, disease progression, and outcomes. This study aimed to systematically review the literature and perform a meta-analysis to comprehensively compare the clinical outcomes between female and male patients with HCM. A thorough search was conducted in databases including PubMed, Embase, Cochrane Library, and Web of Science, encompassing literature from inception until June 2023. The primary endpoints examined were: (1) all-cause mortality; (2) an arrhythmic endpoint comprising sudden cardiac death (SCD), sustained ventricular tachycardia, ventricular fibrillation, or aborted SCD; and (3) a composite endpoint incorporating either (1) or (2), in addition to hospitalization for heart failure or cardiac transplantation. Pooled estimates were derived using a random-effects meta-analysis model. The analysis encompassed a total of 29 observational studies, involving 44,677 patients diagnosed with HCM, of which 16,807 were female. Baseline characteristics revealed that the female group exhibited an advanced age [55.66 ± 0.04 years vs. 50.38 ± 0.03 years, pooled mean difference (MD) = 0.31, 95% CI: 0.22-0.40, p = 0.000, I2 = 88.89%], a higher proportion of New York Heart Association class III/IV patients [pooled odds ratio (OR) = 1.94, 95% CI: 1.55-2.43, p = 0.000, I2 = 85.92%], and a greater prevalence of left ventricular outflow tract gradient greater than or equal to 30 mmHg (pooled OR = 1.48, 95% CI: 1.27-1.73, p = 0.000, I2 = 68.88%) compared to the male group. The female group were more likely to have a positive genetic test (pooled OR = 1.27, 95% CI: 1.08-1.48, p = 0.000, I2 = 42.74%) and to carry the myosin heavy chain beta 7 mutation (pooled OR = 1.26, 95% CI: 1.04-1.54, p = 0.020, I2 = 0.00%) compared to the male group. Female sex exhibited a significant association with increased risks of all-cause mortality (pooled OR = 1.62, 95% CI: 1.38-1.89, p = 0.000, I2 = 72.78%) and the composite endpoint (pooled OR = 1.47, 95% CI: 1.20-1.79, p = 0.000, I2 = 84.96%), while no substantial difference was observed in the arrhythmic endpoint (pooled OR = 1.08, 95% CI: 0.87-1.34, p = 0.490, I2 = 55.48%). The present findings suggest that female patients with HCM tend to experience poorer clinical outcomes. It is imperative to critically reevaluate disease definitions and enhance awareness to mitigate delays in the diagnosis and treatment of HCM in women, thereby fostering equitable healthcare practices. https://www.crd.york.ac.uk/, PROSPERO (CRD42023431881).

Research Review: A systematic review and meta-analysis of sex differences in narrow constructs of restricted and repetitive behaviours and interests in autistic children, adolescents, and adults.

Evidence that autism often manifests differently between males and females is growing, particularly in terms of social interaction and communication, but it is unclear if there are sex differences in restricted and repetitive behaviours and interests (RRBIs) when rigorously focusing on the narrow construct level (i.e., stereotyped behaviour, restricted interests, insistence on sameness, and/or sensory experiences). We conducted a systematic review and four random effects meta-analyses investigating sex differences in narrow construct measures of RRBIs in autistic children, adolescents, and adults (Prospero registration ID: CRD42021254221). Study quality was appraised using the Newcastle-Ottawa Quality Assessment Scale. Forty-six studies were narratively synthesised and 25 of these were included in four random effects meta-analyses. Results found that autistic males had significantly higher levels of stereotyped behaviours (SMD = 0.21, 95% confidence interval (CI) [0.09, 0.33], p < .001) and restricted interests (SMD = 0.18, 95% CI [0.07, 0.29], p < .001) compared to autistic females. In contrast, there were no significant sex differences for sensory experiences (SMD = -0.09, 95% CI [-0.27, 0.09], p = .32) and insistence on sameness (SMD = 0.01, 95% CI [-0.03, 0.05], p = .68). The findings from the narrative synthesis were generally consistent with those from the meta-analyses and also found qualitative sex differences in the way RRBIs manifest. Our findings show significant differences in narrowly defined RRBIs in males and females. Practitioners need to be aware of such differences, which could be contributing to the under-recognition of autism in females and may not be captured by current diagnostic instruments.

Early-life food stress hits females harder than males in insects: A meta-analysis of sex differences in environmental sensitivity.

Fitness consequences of early-life environmental conditions are often sex-specific, but corresponding evidence for invertebrates remains inconclusive. Here, we use meta-analysis to evaluate sex-specific sensitivity to larval nutritional conditions in insects. Using literature-derived data for 85 species with broad phylogenetic and ecological coverage, we show that females are generally more sensitive to food stress than males. Stressful nutritional conditions during larval development typically lead to female-biased mortality and thus increasingly male-biased sex ratios of emerging adults. We further demonstrate that the general trend of higher sensitivity to food stress in females can primarily be attributed to their typically larger body size in insects and hence higher energy needs during development. By contrast, there is no consistent evidence of sex-biased sensitivity in sexually size-monomorphic species. Drawing conclusions regarding sex-biased sensitivity in species with male-biased size dimorphism remains to wait for the accumulation of relevant data. Our results suggest that environmental conditions leading to elevated juvenile mortality may potentially affect the performance of insect populations further by reducing the proportion of females among individuals reaching reproductive age. Accounting for sex-biased mortality is therefore essential to understanding the dynamics and demography of insect populations, not least importantly in the context of ongoing insect declines.

Do girls perform better than boys in school? A meta-analysis of sex differences in academic help seeking behaviours

Do girls perform better than boys in school? A meta-analysis of sex differences in academic help seeking behaviours

A meta-analysis of sex differences in animal personality: no evidence for the greater male variability hypothesis.

The notion that men are more variable than women has become embedded into scientific thinking. For mental traits like personality, greater male variability has been partly attributed to biology, underpinned by claims that there is generally greater variation among males than females in non-human animals due to stronger sexual selection on males. However, evidence for greater male variability is limited to morphological traits, and there is little information regarding sex differences in personality-like behaviours for non-human animals. Here, we meta-analysed sex differences in means and variances for over 2100 effects (204 studies) from 220 species (covering five broad taxonomic groups) across five personality traits: boldness, aggression, activity, sociality and exploration. We also tested if sexual size dimorphism, a proxy for sex-specific sexual selection, explains variation in the magnitude of sex differences in personality. We found no significant differences in personality between the sexes. In addition, sexual size dimorphism did not explain variation in the magnitude of the observed sex differences in the mean or variance in personality for any taxonomic group. In sum, we find no evidence for widespread sex differences in variability in non-human animal personality.

Does sex really matter?

Does sex really matter?

Boys are more likely to be undernourished than girls: a systematic review and meta-analysis of sex differences in undernutrition

BackgroundExcess male morbidity and mortality is well recognised in neonatal medicine and infant health. In contrast, within global nutrition, it is commonly assumed that girls are more at risk of...

Meta-Analysis of Sex Differences in ADHD Symptoms and Associated Cognitive Deficits

Objective: A meta-analysis was carried out to determine whether there are sex differences among children and adolescents with ADHD on the primary symptoms of ADHD and on executive and attentional functioning. Method: Studies published from 1997 to 2017 comparing boys and girls with a valid ADHD diagnosis were retained. Results: The meta-analysis found boys with ADHD to be more hyperactive than girls with ADHD and boys to have more difficulties in terms of motor response inhibition and cognitive flexibility. Results also confirm that youths with ADHD have more executive deficits than non-ADHD peers have, but there is no sex difference in this regard. Conclusion: Results show that there are sex differences in the behavioral expression of the difficulties related to ADHD. This highlights the importance of pursuing research to refine the profile of girls with ADHD and to develop diagnostic criteria adapted to each sex.

Systematic Review and Meta-Analysis of Sex Differences in Social Contact Patterns and Implications for Tuberculosis Transmission and Control.

Social contact patterns might contribute to excess burden of tuberculosis in men. We conducted a study of social contact surveys to evaluate contact patterns relevant to tuberculosis transmission. Available data describe 21 surveys in 17 countries and show profound differences in sex-based and age-based patterns of contact. Adults reported more adult contacts than children. Children preferentially mixed with women in all surveys (median sex assortativity 58%, interquartile range [IQR] 57%–59% for boys, 61% [IQR 60%–63%] for girls). Men and women reported sex-assortative mixing in 80% and 95% of surveys (median sex assortativity 56% [IQR 54%–58%] for men, 59% [IQR 57%–63%] for women). Sex-specific patterns of contact with adults were similar at home and outside the home for children; adults reported greater sex assortativity outside the home in most surveys. Sex assortativity in adult contacts likely contributes to sex disparities in adult tuberculosis burden by amplifying incidence among men.

A Systematic Review and Meta-analysis of Sex Differences in Morbidity and Mortality of Acute Lower Respiratory Tract Infections Among African Children.

Although biological sex influences Acute Lower Respiratory Tract Infections (ALRIs) morbidity and mortality patterns in children living in sub-Saharan Africa, the exact mechanism about the effect is unknown. We assessed the quality and strength of evidence on the association of sex with incidence, etiology, and outcomes of ALRI in African children. We systematically searched electronic databases for publications from 1971-2016 in PubMed, African Journals Online, and Google scholar for ALRI literature in the African children. We used (pneumonia OR bronchiolitis OR "community-acquired pneumonia" OR CAP OR "hospital-acquired pneumonia" OR "nosocomial pneumonia" OR "ventilator-acquired pneumonia" OR "lung abscess" OR "pleural effusion" OR "empyema thoracis") AND (sex OR gender) AND (Africa OR Sub-Saharan) as search terms. We included the published peer-reviewed journal articles reporting on incidence, etiology, and case fatality. We summarized the findings using narrative and meta-analysis methods. We included 14 studies with sex-related data; the median (IQR) number of reported pneumonia cases was 148 (87-770) and 114 (56-599) for male and female patients, respectively. Only two studies reported a sex-specific incidence. The odds of sex were in favor of male sex, and the chances of identification of Respiratory Syncytia Virus (RSV) were significantly lower in males than in females (OR=0.60; 95% CI: 0.42, 0.86). Estimates from 9 studies showed that the death rate for males was significantly higher than for females (OR=1.26; 95% CI=1.20-1.33). Sex-disaggregated data on incidence, etiology, and case fatality of pneumonia are scarcely reported in studies published in Africa. However, males appear to die more often than females, and females more likely to have RSV infection.

Metacognitive beliefs in individuals at risk for psychosis: asystematic review and meta-analysis of sex differences.

SummaryBackgroundSex differences were found in several domains in individuals at ultra-high risk for psychosis, but no previous work has systematically reviewed and analysed possible sex differences in metacognition in this population. However, alterations in metacognitive beliefs have been shown in the at-risk mental state for psychosis population. Our aim was to qualitatively review and quantitatively analyse the existing literature for data on sex differences in metacognitive beliefs—mainly depicted by the Metacognitions Questionnaire (MCQ) and its short form (MCQ-30)—in individuals with at-risk mental states.MethodsWe performed a systematic review of the literature on metacognition in help-seeking adolescents and young adults at ultra-high risk for psychosis. We included peer-reviewed articles that included a high-risk for psychosis group assessed with operationalised criteria and instruments. For the quantitative meta-analysis, only studies comparing MCQ data in high-risk individuals were included. A fixed-effect meta-model was used and forest plots drawn for each subscale and overall score. The studies were weighted according to the inverse variance method in order to calculate pooled confidence intervals and p values.ResultsNo article on metacognitive beliefs in individuals at increased risk for psychosis explicitly reported possible sex differences. Our meta-analysis of 234 (57% male) individuals’ scores in the MCQ yielded no significant sex difference.ConclusionsCurrently, no sex differences in metacognition can be described in the at-risk population; however, data are insufficient and heterogeneous with regard to thoroughly answering the question whether sex differences in clinical high-risk populations are mirrored in the metacognitive domain.

Effect of metformin on the mortality of colorectal cancer patients with T2DM: meta-analysis of sex differences.

To evaluate the effect of metformin as a treatment for the mortality of colorectal cancer (CRC) patients with type 2 diabetes mellitus (T2DM). We searched Medline, PubMed, EMBASE, Clinical Trials.gov (http://www.clinicaltrials.gov), and the Cochrane Collaboration Library from inception to November 2019. To analyze the relationship between metformin and the overall mortality, specific mortality, and sex differences in CRC patients with T2DM, hazard ratios (HRs) with 95% confidence intervals (CIs) were used. Egger's test and Begg's test were used to assess publication bias. We included 8 cohort studies in our meta-analysis. CRC patients with T2DM treated with metformin had a lower overall mortality than CRC patients with T2DM who did not receive metformin (HR = 0.80, 95% CI 0.67-0.95). There was no significant difference in CRC-specific mortality between CRC patients with T2DM who used metformin and those who did not (HR = 0.84, 95% CI 0.65-1.08). However, females had a lower CRC-specific mortality among CRC patients with T2DM than males (HR = 0.63, 95% CI 0.41-0.97). Metformin reduced the overall mortality of CRC patients with T2DM. Moreover, female CRC patients with T2DM using metformin had lower CRC-specific mortality than male CRC patients with T2DM.

What did you do yesterday? A meta-analysis of sex differences in episodic memory.

To remember what one did yesterday is an example of an everyday episodic memory task, in which a female advantage has sometimes been reported. Here, we quantify the impact of sex on episodic memory performance and investigate whether the magnitude of the sex difference is modified by study-, task-, and sample-specific moderators. Analyses were based on 617 studies conducted between 1973 and 2013 with 1,233,921 participants. A 5-level random-effects meta-analysis showed an overall female advantage in episodic memory (g = 0.19, 95% CI [0.17, 0.21]). The material to be remembered affected the magnitude of this advantage, with a female advantage for more verbal tasks, such as words, sentences, and prose (g = 0.28, 95% CI [0.25, 0.30]), nameable images (g = 0.16, 95% CI [0.11, 0.22]), and locations (g = 0.16, 95% CI [0.11, 0.21]), and a male advantage in more spatial tasks, such as abstract images (g = -0.20, 95% CI [-0.35, -0.05]) and routes (g = -0.24, 95% CI [-0.35, -0.12]). Furthermore, there was a female advantage for materials that cannot easily be placed along the verbal-spatial continuum, such as faces (g = 0.26, 95% CI [0.20, 0.33]), and odor, taste, and color (g = 0.37, 95% CI [0.18, 0.55]). These differences have remained stable since 1973. For verbal episodic memory tasks, differences were larger in Europe, North America, Oceania, and South America than in Asia, and smaller in childhood and old age than for other ages. Taken together, results suggest that men may use their spatial advantage in spatially demanding episodic memory tasks, whereas women do well in episodic memory tasks that are verbalizable and tasks that are neither verbal nor spatial, such as remembering faces and odors/tastes/colors. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

A meta-analysis of sex differences in human navigation skills.

There are inconsistent reports regarding behavioral sex differences in the human navigation literature. This meta-analysis quantifies the overall magnitude of sex differences in large-scale navigation skills in a variety of paradigms and populations, and examines potential moderators, using 694 effect sizes from 266 studies and a multilevel analytic approach. Overall, male participants outperform female participants, with a small to medium effect size (d = 0.34 to 0.38). The type of task, the type of dependent variable and the testing environment significantly contribute to variability in effect sizes, although there are only a few situations in which differences are either nonexistent or very large. Pointing and recall tasks (and the deviation scores associated with them) show larger sex differences than distance estimation tasks or learning to criterion. Studies with children younger than 13 years showed much smaller effect sizes (d = .15) than older age groups. We discuss the implications of these findings for understanding sex differences in human spatial navigation and identify avenues for future navigation research.

Supplemental Material for What Did You Do Yesterday? A Meta-Analysis of Sex Differences in Episodic Memory

Supplemental Material for What Did You Do Yesterday? A Meta-Analysis of Sex Differences in Episodic Memory

Sex differences in romantic attachment among Chinese: A meta-analysis

Although several studies support evolutionary perspectives on sex differences in romantic attachment, these sex differences in East Asia remain controversial. To estimate the effect size of sex differences in romantic attachment among Chinese adults, a meta-analysis of sex differences was conducted in the present study. This meta-analysis was based on 111 samples using the Chinese version of the Experiences in Close Relationships Scale and its revised version. The findings suggest that the effect size of sex differences in romantic attachment among Chinese adults is relatively small. Overall, females demonstrated higher anxiety and avoidance than males, with substantial between-study heterogeneity. Sex differences were largest in community samples, with higher avoidance and lower anxiety in males. There were smaller sex differences in college student samples, with higher anxiety and avoidance in females. The degree of sex differences also varied across geographical regions, with high-stress and high-fertility reproductive environments showing smaller sex differences in general and larger sex differences in extreme conditions. Sex differences in anxiety increased linearly with age, whereas those in avoidance remained unchanged. The results support evolutionary perspectives of sex differences in romantic attachment, which assume that the average sex differences in romantic attachment styles should be relatively small in most populations, and many possible factors might moderate such differences. The heterogeneity and limitations of the current findings and directions for future research on sex differences in romantic attachment are discussed.

Sex difference in awareness of threat: A meta-analysis of sex differences in attentional orienting in the dot probe task

It has been argued that females are more important to infant survival than males and that his may lead to their increased fear. One way of increasing female survival chances would be to increase their sensitivity to threat. The dot-probe task has been used to investigate attentional bias. In this meta-analysis we combine the results of dot-probe experiments and explicitly examine sex differences in attentional orienting bias. Overall there is little evidence to support the existence of sex differences and these results are considered in terms of evolutionary impact.

Meta-analysis of sex differences in gene expression in schizophrenia.

Schizophrenia is a severe psychiatric disorder which influences around 1 % of the worldwide population. Differences between male and female patients with schizophrenia have been noted. There is an earlier age of onset in males compared with females with this diagnosis, and in addition, there are differences in symptom profiles between the sexes. The underlying molecular mechanism of sex difference remains unclear. Here we present a comprehensive analysis to reveal the sex differences in gene expression in schizophrenia with stringent statistics criteria. We compiled a data set consisting of 89 male controls, 90 male schizophrenia patients, 35 female controls and 32 female schizophrenia patients from six independent studies of the prefrontal cortex (PFC) in postmortem brain. When we tested for a sex by diagnosis interaction on gene expression, 23 genes were up-regulated and 23 genes were down-regulated in the male group (q-value < 0.05), several genes are related to energy metabolism, while 4 genes are located on sex chromosome. No genes were statistically significant in the female group when multiple testing correction were conducted (q-value <0.05), most likely due to the small sample size. Our protocol and results from the male group provide a starting point for identifying the underlying different mechanism between male and female schizophrenia patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s12918-015-0250-3) contains supplementary material, which is available to authorized users.

Are there differences in disease progression and mortality among male and female HIV patients on antiretroviral therapy? A meta-analysis of observational cohorts

ABSTRACTStudies examining the sex differences in morbidity and mortality among HIV/AIDS patients have yielded inconsistent results. We conducted a meta-analysis of sex differences in disease progression and mortality among HIV/AIDS patients. Medical literature databases from inception to August 2014 were searched for published observational studies assessing sex differences in immunologic and virologic response, disease progression and mortality among HIV-infected patients. Random effects meta-analyses of 115 eligible studies were conducted to obtain pooled estimates of outcomes and heterogeneity was explored in sub-group analyses. Pooled estimates showed an increased risk of progression to AIDS (relative risk [RR]=1.11,95% CI=1.02–1.21) and all-cause mortality (RR=1.23, 95% CI=1.17–1.29) among males compared to females. All-cause mortality differed by sex only in low and middle income countries. The risk of AIDS-related mortality (RR=1.03, 95% CI=0.82–1.30), immunologic failure (RR=1.19,95% CI: 0.97–1.47), virologic suppression (RR=0.98, 95% CI=0.84–1.14), virologic failure (RR=1.26, 95% CI=0.99–1.61) and the change in CD4 cell count (Weighted mean difference [WMD] = −5.15, 95% CI= −13.57 to 3.28) did not differ by sex. These findings were modified by disease severity, adherence and use of highly active antiretroviral therapy. We conclude that HIV-related disease progression and survival outcomes are poorer in males.