Gender bias in research: how does it affect evidence based medicine?

Sex differences in acute early life stress-enhanced fear learning in adult rats

Patients diagnosed with posttraumatic stress disorder (PTSD) present with a spectrum of debilitating anxiety symptoms resulting from exposure to trauma. Women are twice as likely to be diagnosed with anxiety and PTSD compared to men; however, the reason for this vulnerability remains unknown. We conducted four experiments where we first demonstrated a female vulnerability to stress-enhanced fear learning (SEFL) with a moderate, acute early life stress (aELS) exposure (4 footshocks in a single session), compared to a more intense aELS exposure (15 footshocks in a single session) where males and females demonstrated comparable SEFL. Next, we demonstrated that this female vulnerability does not result from differences in footshock reactivity or contextual fear conditioning during the aELS exposure. Finally, using gonadectomy or sham surgeries in adult male and female rats, we showed that circulating levels of gonadal steroid hormones at the time of adult fear conditioning do not explain the female vulnerability to SEFL. Additional research is needed to determine whether this vulnerability can be explained by organizational effects of gonadal steroid hormones or differences in sex chromosome gene expression. Doing so is critical for a better understanding of increased female vulnerability to certain psychiatric diseases.

Circadian disruption during fetal development promotes pathological cardiac remodeling in male mice

Disruption of circadian rhythms during fetal development may predispose mice to developing heart disease later in life. Here, we report that male, but not female, mice that had experienced chronic circadian disturbance (CCD) in utero were more susceptible to pathological cardiac remodeling compared with mice that had developed under normal intrauterine conditions. CCD-treated males showed ventricular chamber dilatation, enhanced myocardial fibrosis, decreased contractility, higher rates of induced tachyarrhythmia, and elevated expression of biomarkers for heart failure and myocardial remodeling. In utero CCD exposure also triggered sex-dependent changes in cardiac gene expression, including upregulation of the secretoglobin gene, Scgb1a1, in males. Importantly, cardiac overexpression of Scgb1a1 was sufficient to induce myocardial hypertrophy in otherwise naive male mice. Our findings reveal that in utero CCD exposure predisposes male mice to pathological remodeling of the heart later in life, likely as a consequence of SCGB1A1 upregulation.

Women in science: myth, harsh reality, or advantage

To initiate discussion on women in science, we begin with Gerald Edelman's definition: "Science is imagination in the service of the verifiable truth," which underscores "verifiability," truth reached by evidence, as the pathway science charts to Truth. "Verifiability" is named after the Roman Goddess Veritas, the daughter of Cronos and the mother of Virtus, suggesting that mythology viewed science as embodied by a female, embedded in its historical time, and aimed to breed values. We contemplate three perspectives on the topic and discuss their potential risks. The Veracity (Veritas) Perspective holds that science is impartial to the gender, race, political camp, or religious affiliation of its practitioner and from this perspective "women in sciences" is an oxymoron; science is, essentially, genderless. We argue that this perspective is misleading. Becoming a scientist requires education, resources, encouragement, training, role models, time, and funding, and the lack of such provisions banned women from the gates of Truth. The Harsh Reality perspective brings data presenting a grim picture. From 1902 to 2022 only 3.6% of Nobel Prizes in sciences were awarded to women and percentages of women in top academic positions are a third or lower across the US and Europe despite earning about 50% of PhDs in sciences. We contemplate internal and external reasons for this reality. Finally, the Potential Advantage position asks whether women may have unique sensitivities in the road to cumulative knowledge. We base our discussion on 20th century philosophical models that call to move from the metaphysical and abstract to the daily and contextual in the acquisition of knowledge and on research describing the distinct neural pathways to motherhood and fatherhood. We conclude by highlighting our unique historical time and the emergence of novel topics in neuroscience through the work of female and male scientists; interaction synchrony, inter-brain communication, and social and affiliative neuroscience.

Reconsidering the Conceptualization of Resilience: The Experiences of Refugee and Immigrant Youth in Montreal

Over the last two decades, immigrant and refugee integration service agencies in Canada have been incorporating a focus on resiliency in their work and hold "fostering resilience" as a primary goal of services. These agencies focus on helping their clients enhance resilience in response to their integration challenges. Refugee and immigrant youth (RIY) face intersectional vulnerabilities during their resettlement process. These challenges make the concept of resilience vital to their success. However, resettlement service providers associate RIY's resilience with their assimilation into the Western culture such as integrating into the dominant culture. This definition is insensitive to cultural and social factors that contextualize RIY's definition of resilience. Drawing from in-depth interviews of Refugees and Immigrant youths in Montreal, and using Resilience as a conceptual framework, the research study investigated the barriers to the integration of RIY and their conceptualization of resilience. The study found social isolation, cultural differences between the host and home communities, racism, hostility, aggression, and language to be barriers to RIY's integration. The youth conceptualized resilience as a form of adaptability to any situation; as the ability to integrate into a new society while remaining deeply rooted in one's culture and past experiences; and overcoming marginalization. The paper contributes to a nuanced critical understanding in the field of refugee and migration studies and further throws light on a growing triangular interrelationship between social and economic integration of refugees, cultural factors of host communities, and resilience.

Gender data gap in military research: a review of the participation of men and women in military musculoskeletal injury studies

Servicewomen are at increased risk of musculoskeletal injuries compared with their male counterparts, but women are under-represented in sports medicine research. The aim of this review was to assess the representation of women in military musculoskeletal injury studies. PubMed was searched for human original research studies using the terms Military OR Army OR Navy OR 'Air Force' AND 'musculoskeletal injury' Each study was categorised as epidemiology (basic training), epidemiology (trained personnel), risk factors, interventions and other. The number of male and female participants was retrieved from each study. A total of 262 studies were included: 98 (37%) studies only included men, 17 (6%) studies only included women and 147 (56%) studies included both men and women. A total of 8 051 778 participants were included in these studies (men: 6 711 082, 83%; women: 1 340 696, 17%). The study theme with the greatest proportion of women was musculoskeletal injury epidemiology studies in a basic training population (20% of participants) with the lowest proportion of women in intervention trials (6% of participants). These data suggest women are not under-represented in military musculoskeletal injury studies when considering the gender representation of most militaries. Our data are, however, biased by large epidemiological trials and women were under-represented in intervention trials. The under-representation of women in intervention trials could be due to difficulties in controlling for the effects of female sex steroids on musculoskeletal outcomes, or a focus on interventions in the most arduous military roles where injury risk is highest and women have been previously excluded.

Sexual Dimorphism in the Expression of Cytochrome P450 Enzymes in Rat Heart, Liver, Kidney, Lung, Brain, and Small Intestine

Cytochrome P450 (P450) enzymes are monooxygenases that are expressed hepatically and extrahepatically and play an essential role in xenobiotic metabolism. Substantial scientific evidence indicates sex-specific differences between males and females in disease patterns and drug responses, which could be attributed, even partly, to differences in the expression and/or activity levels of P450 enzymes in different organs. In this study, we compared the mRNA and protein expression of P450 enzymes in different organs of male and female Sprague-Dawley rats by real-time polymerase chain reaction and western blot techniques. We found significant sex- and organ-specific differences in several enzymes. Hepatic Cyp2c11, Cyp2c13, and Cyp4a2 showed male-specific expression, whereas Cyp2c12 showed female-specific expression. Cyp2e1 and Cyp4f enzymes demonstrated higher expression in the female heart and kidneys compared with males; however, they showed no significant sexual dimorphism in the liver. Male rats showed higher hepatic and renal Cyp1b1 levels. All assessed enzymes were found in the liver, but some were not expressed in other organs. At the protein expression level, CYP1A2, CYP3A, and CYP4A1 demonstrated higher expression levels in the females in several organs, including the liver. Elucidating sex-specific differences in P450 enzyme levels could help better understand differences in disease pathogeneses and drug responses between males and females and thus improve treatment strategies. SIGNIFICANCE STATEMENT: This study characterized the differences in the mRNA and protein expression levels of different cytochrome P450 (P450) enzymes between male and female rats in the heart, liver, lung, kidney, brain, and small intestine. It demonstrated unique sex-specific differences in the different organs. This study is considered a big step towards elucidating sex-specific differences in P450 enzyme levels, which is largely important for achieving a better understanding of the differences between males and females in the disease's processes and treatment outcomes.

"I Just Want to Feel Safe Going to a Doctor": Experiences of Female Patients with Chronic Conditions in Australia

Background

The androcentric history of medicine and medical research has led to an ongoing sex and gender gap in health research and education. Sex and gender gaps in research and education may translate into real-life health inequities for women. This study aimed to explore the experiences of female patients with chronic health conditions in the Australian health system, considering existing sex and gender gaps in medicine.

Methods

This qualitative study used semistructured in-depth interviews with a sample of adult women with chronic conditions in Australia. Thematic analysis was undertaken, guided by Braun and Clarke. Software NVivoX64 assisted in the management of the data. Coding was performed before grouping into subthemes and central themes. To allow for potential researcher biases, the principal researcher engaged in the practice of reflexivity, including the writing of detailed notes during analysis.

Results

Twenty adult Australian women with chronic conditions were interviewed. Diagnoses were varied and included Ehlers-Danlos syndrome, chronic fatigue syndrome, functional neurological disorder, and inflammatory bowel disease. Four central themes emerged: diagnostic difficulties; spectrum of health care experiences; understanding medical complexity; and coping with symptoms.

Conclusions

Women with chronic conditions in Australia report pain, fatigue, and suffering that significantly impacts upon their daily lives. There was a shared experience of feeling that the pain and suffering of women was dismissed or not taken seriously. Many women expressed trauma because of their experiences in health care and often this led to a fear of accessing health services. The participants highlighted a need for more knowledge, understanding, and empathy from health care practitioners.

Sex differences in allometry for phenotypic traits in mice indicate that females are not scaled males

Sex differences in the lifetime risk and expression of disease are well-known. Preclinical research targeted at improving treatment, increasing health span, and reducing the financial burden of health care, has mostly been conducted on male animals and cells. The extent to which sex differences in phenotypic traits are explained by sex differences in body weight remains unclear. We quantify sex differences in the allometric relationship between trait value and body weight for 363 phenotypic traits in male and female mice, recorded in >2 million measurements from the International Mouse Phenotyping Consortium. We find sex differences in allometric parameters (slope, intercept, residual SD) are common (73% traits). Body weight differences do not explain all sex differences in trait values but scaling by weight may be useful for some traits. Our results show sex differences in phenotypic traits are trait-specific, promoting case-specific approaches to drug dosage scaled by body weight in mice.

Randomised controlled trials in medical AI: ethical considerations

In recent years, there has been a surge of high-profile publications on applications of artificial intelligence (AI) systems for medical diagnosis and prognosis. While AI provides various opportunities for medical practice, there is an emerging consensus that the existing studies show considerable deficits and are unable to establish the clinical benefit of AI systems. Hence, the view that the clinical benefit of AI systems needs to be studied in clinical trials-particularly randomised controlled trials (RCTs)-is gaining ground. However, an issue that has been overlooked so far in the debate is that, compared with drug RCTs, AI RCTs require methodological adjustments, which entail ethical challenges. This paper sets out to develop a systematic account of the ethics of AI RCTs by focusing on the moral principles of clinical equipoise, informed consent and fairness. This way, the objective is to animate further debate on the (research) ethics of medical AI.

Evidence-Based Medicine: Feminist Criticisms and Implications for Women's Health

Evidence-based medicine (EBM) dates back to 19th-century Paris and started out as a new paradigm for practicing medicine, with the aim of replacing anecdote with high-quality evidence from positivist-style research. Despite the clear logic underpinning EBM, there have been numerous criticisms, including maintenance of an archaic view of evidence as "facts," failure to acknowledge that all research is underpinned by the beliefs of the researcher, and the simple fact that medical research has historically been androcentric and results generalized to female patients. In this essay, we discuss the criticisms of EBM, with a focus on feminist critiques based on three central feminist epistemologies: feminist empiricism, standpoint theory, and social constructivism. We argue that EBM potentially perpetuates gaps in women's health and advocate for incorporating feminist epistemologies into future medical research to garner further understanding of social influences on women's health. In addition, we argue that EBM may degrade the clinical acumen and that critical thinking should become a key component of medical school curricula.

Authorship diversity in Gastroenterology-related Cochrane systematic reviews: Inequities in global representation

The need for promoting diversity and equitable authorship representation in academics faces increasing recognition, with some articles pointing out the lack of diversity in specific fields. Currently, there are no such articles scrutinizing the author diversity in the field of Gastroenterology. Cochrane systematic reviews are perceived worldwide to be amongst the highest quality of evidence available, thereby its conclusions often impact policy and practice globally. However, little is known about the current state of authorship diversity in Gastroenterology-related Cochrane reviews.

Statin treatment effectiveness and the SLCO1B1*5 reduced function genotype: long-term outcomes in women and men

Objective

To estimate the effect of rs4149056 (SLCO1B1*5) genotype (decreases statin transport) on cholesterol control and treatment duration in male and female primary care patients prescribed common statin medications.

Methods and Analysis

This study comprised 69 185 European‐ancestry UK Biobank cohort participants prescribed simvastatin or atorvastatin (aged 40‐79 years at first prescription, treatment duration 1 month to 29 years, mean 5.7 years). Principal outcomes were clinically high total cholesterol (>5 mmol/L) at baseline, plus treatment discontinuation.

Results

A total of 48.4% of 591 females homozygous for SLCO1B1*5 decreased function genotype had raised cholesterol vs 41.7% of those with functioning SLCO1B1 (odds ratio 1.31, 95% confidence interval [CI] 1.1‐1.55, P = .001). Fewer males had high cholesterol and the genotype effect was attenuated. In primary care prescribing, females homozygous for SLCO1B1*5 were more likely to stop receiving these statins (29.5%) than women with normal SLCO1B1 (25.7%) (hazard ratio [HR] 1.19, 95% CI 1.03‐1.37, P = .01), amounting to five discontinuations per 100 statin‐years in the SLCO1B1*5 group vs four in the normal SLCO1B1 function group. This remained significant after the first year of treatment (HR for discontinuing >1 year after first prescription 1.3, 95% CI 1.08‐1.56, P = .006). In men SLCO1B1*5 was only associated with treatment discontinuation in the first year.

Conclusions

In this large community sample of patients on commonly prescribed statins, the SLCO1B1*5 decreased function variant had much larger effects on cholesterol control and treatment duration in women than in men. Efforts to improve the effectiveness of statin therapy in women may need to include SLCO1B1*5 genotype‐guided statin selection.

Mechanisms and implications of sex differences in cardiac aging

Aging promotes structural and functional remodeling of the heart, even in the absence of external factors. There is growing clinical and experimental evidence supporting the existence of sex-specific patterns of cardiac aging, and in some cases, these sex differences emerge early in life. Despite efforts to identify sex-specific differences in cardiac aging, understanding how these differences are established and regulated remains limited. In addition to contributing to sex differences in age-related heart disease, sex differences also appear to underlie differential responses to cardiac stress such as adrenergic activation. Identifying the underlying mechanisms of sex-specific differences may facilitate the characterization of underlying heart disease phenotypes, with the ultimate goal of utilizing sex-specific therapeutic approaches for cardiac disease. The purpose of this review is to discuss the mechanisms and implications of sex-specific cardiac aging, how these changes render the heart more susceptible to disease, and how we can target age- and sex-specific differences to advance therapies for both male and female patients.

The Role of Fatty Acid Metabolites in Vaginal Health and Disease: Application to Candidiasis

Although the vast majority of women encounters at least one vaginal infection during their life, the amount of microbiome-related research performed in this area lags behind compared to alternative niches such as the intestinal tract. As a result, effective means of diagnosis and treatment, especially of recurrent infections, are limited. The role of the metabolome in vaginal health is largely elusive. It has been shown that lactate produced by the numerous lactobacilli present promotes health by limiting the chance of infection. Short chain fatty acids (SCFA) have been mainly linked to dysbiosis, although the causality of this relationship is still under debate. In this review, we aim to bring together information on the role of the vaginal metabolome and microbiome in infections caused by Candida. Vulvovaginal candidiasis affects near to 70% of all women at least once in their life with a significant proportion of women suffering from the recurrent variant. We assess the role of fatty acid metabolites, mainly SCFA and lactate, in onset of infection and virulence of the fungal pathogen. In addition, we pinpoint where lack of research limits our understanding of the molecular processes involved and restricts the possibility of developing novel treatment strategies.

The chest wall gender divide: females have better cardiopulmonary function and exercise tolerance despite worse deformity in pectus excavatum

PURPOSE

Pectus excavatum (PE) is a chest wall deformity of variable severity and symptomatology. Existing female-specific literature highlights breast asymmetry and cosmetic reconstruction. We sought to evaluate gender differences in cardiopulmonary function.

METHODS

Cardiac MRIs, pulmonary function tests (PFTs), and cardiopulmonary exercise tests (CPETs) were reviewed in 345 patients undergoing preoperative evaluation for PE. Regression modeling was used to evaluate associations between gender and clinical endpoints of cardiopulmonary function.

RESULTS

Mean age was 15.2 years, 19% were female, 98% were white. Pectus indices included median Haller Index (HI) of 4.8, mean depression index (DI) of 0.63, correction index (CI) of 33.6%, and Cardiac Compression Index (CCI) of 2.79. Cardiac assessment revealed decreased right and left ventricular ejection fraction (RVEF, LVEF) in 16% and 22% of patients, respectively. PFTs and CPETs were abnormal in ~ 30% of patients. While females had deeper PE deformities-represented by higher pectus indices-they had superior function with higher RVEF, LVEF Z-scores, FEV₁, VO₂ max, O₂ pulse, work, and breathing reserve (p < 0.05).

CONCLUSION

Despite worse PE deformity and symptomatology, females had a better cardiopulmonary function and exercise tolerance than males. Further research is needed to assess the precise mechanisms of this phenomenon and postoperative outcomes in this population.

The effect of gender and ABCB1 gene polymorphism on the pharmacokinetics of azithromycin in healthy male and female Pakistani subjects

In the current study, the possible outcome of gender difference and genotypic polymorphism of the ABCB1 gene encoding P-glycoprotein on the pharmacokinetics of azithromycin has been evaluated. An open-label, comparative pharmacokinetic study was done in healthy Pakistani volunteers (females (n = 8) and males (n = 8)). They were administered a single 500 mg oral dose of azithromycin. Blood samples (≈5 mL) were collected in heparinized tubes and the HPLC/MS/MS method was used to determine azithromycin plasma levels. ABCB1 polymorphism (single nucleotide polymorphisms) at C3435T, G26SST was performed using the RFLP-PCR method. The Student t test was applied to compare pharmacokinetic parameters of azithromycin between male and female human subjects (at 95% CI) using GraphPad Prism-8. A significant difference was observed in pharmacokinetic parameters between males and females, as C_max in males (230 ± 80.2 ng/mL) was significantly higher than in females (224.9 ± 75.5 ng/mL), while [Formula: see text] was also significantly higher (p < 0.05) in males (2102 ± 200.3 ng·h^-1·mL^-1) compared to females (1825.7 ± 225.4 ng·h^-1·mL^-1). There was a significant variation in C_max and AUC in three ABCB1 genotyping groups as well. Gender difference and ABCB1 gene polymorphisms have a significant impact on the pharmacokinetics of azithromycin, as they contribute to interindividual variability in therapeutic response.

Age-related sex differences in the expression of important disease-linked mitochondrial proteins in mice

The prevalence and progression of many illnesses, such as neurodegenerative and cardiovascular diseases, obesity, and cancer, vary between women and men, often in an age-dependent manner. A joint hallmark of these diseases is some type of mitochondrial dysfunction. While several mitochondrial proteins are known to be regulated by sex hormones, the levels of those proteins have not been systematically analyzed with regard to sex and age, and studies that consider sex and/or age differences in the protein expression are very rare. In this study, we compared the expression patterns of physiologically important mitochondrial proteins in female and male C57BL/6N mice of age cohorts frequently used in experiments. We found that sex-related differences in the expression of uncoupling proteins 1 and 3 (UCP1 and UCP3) occur in an age-dependent manner. The sex-specific expression of UCP1 and UCP3 in brown adipose tissue (BAT) was inversely correlated with differences in body weight. Expression of UCP4 in the brain, Complex I in the spleen, and Complex II in the brain and BAT was least affected by the sex of the mouse. We further demonstrated that there are serious limitations in using VDAC1 and actin as markers in western blot analyses, due to their sex- and age-specific fluctuations. Our results confirm that sex and age are important parameters and should be taken into account by researchers who examine the mechanistic aspects of diseases. HIGHLIGHTS: I.The levels of UCP1 and UCP3 protein expression differ between females and males in an age-dependent manner.II.Pre-pubertal expression of almost all proteins tested in this study does not depend on the sex of the mouse.III.Expression of VDAC1 and actin, which are often used as loading control proteins in western blot analysis, is tissue-specifically influenced by sex and age.

Meeting the needs of underserved populations: setting the agenda for more inclusive citizen science of medicine

In its expansion to genomic, epidemiological and biomedical research, citizen science has been promoted as contributing to the democratisation of medical research and healthcare. At the same time, it has been criticised for reinforcing patterns of exclusion in health and biomedicine, and sometimes even creating new ones. Although citizen science has the potential to make biomedical research more inclusive, the benefits of current citizen science initiatives are not equally accessible for all people-in particular those who are resource-poor, located outside of traditional networks of healthcare services, or members of minorities and marginalised groups. In view of growing public investments in participatory research endeavours, we argue that it should be considered more explicitly if, and how, citizen science could help make research more inclusive, contribute to the public good, and possibly even lead to better and more equitable healthcare. Reflecting on emerging ethical concerns for scientific conduct and best medical practice, we propose a set of relevant considerations for researchers, practitioners, bioethicists, funders and participants who seek to advance ethical practices of citizen-led health initiatives, and address profound differences in position, privilege and power in research.

Medicine is Patriarchal, But Alternative Medicine is Not the Answer

Women are over-represented within alternative medicine, both as consumers and as service providers. In this paper, I show that the appeal of alternative medicine to women relates to the neglect of women's health needs within scientific medicine. This is concerning because alternative medicine is severely limited in its therapeutic effects; therefore, those who choose alternative therapies are liable to experience inadequate healthcare. I argue that while many patients seek greater autonomy in alternative medicine, the absence of an evidence base and plausible mechanisms of action leaves patients unable to realize meaningful autonomy. This seems morally troubling, especially given that the neglect of women's needs within scientific medicine seems to contribute to preferences for alternative medicine. I conclude that the liberatory credentials of alternative medicine should be questioned and make recommendations to render scientific medicine better able to meet the needs of typical alternative medicine consumers.

The art of co-production of knowledge in environmental sciences and management: lessons from international practice

This review paper addresses the challenging question of "how to" design and implement co-production of knowledge in climate science and other environmental and agricultural sciences. Based on a grounded theory review of nine (9) published case studies of transdisciplinary and collaborative research projects, the paper offers a set of common themes regarding specific components and processes for the design, implementation, and achievement of co-production of knowledge work, which represent the "Modus Operandi" of knowledge co-production. The analysis focuses on practical methodological guidance based on lessons from how different research teams have approached the challenges of complex collaborative research. We begin by identifying broad factors or actions that inhibit or facilitate the process, then highlight specific practices associated with co-production of knowledge and necessary competencies for undertaking co-production. We provide insights on issues such as the integration of social and professional cultures, gender and social equity, and power dynamics, and illustrate the different ways in which researchers have addressed these issues. By exploring the specific practices involved in knowledge co-production, this paper provides guidance to researchers on how to navigate different possibilities of the process of conducting transdisciplinary and co-production of knowledge research projects that best fit their research context, stakeholder needs, and research team capacities.

Sex differences in acupuncture effectiveness in animal models of Parkinson's disease: a systematic review

Background

Many animal experimental studies have been performed to investigate the efficacy of acupuncture in Parkinson’s disease (PD). Sex differences are a major issue in all diseases including PD. However, to our knowledge, there have been no reviews investigating sex differences on the effectiveness of acupuncture treatment for animal PD models. The current study aimed to summarize and analyze past studies in order to evaluate these possible differences.

Method

Each of 7 databases (MEDLINE, EMBASE, the Cochrane Library, 3 Korean medical databases, and the China National Knowledge Infrastructure) was searched from its inception through March 2015 without language restrictions.

Results

We included studies of the use of acupuncture treatment in animal models of PD. A total of 810 potentially relevant articles were identified, 57 of which met our inclusion criteria. C57/BL6 mice were used most frequently (42 %) in animal PD models. Most of the studies were carried out using only male animals (67 %); only 1 study (2 %) was performed using solely females. The further 31 % of the studies used a male/female mix or did not specify the sex.

Conclusions

The results of our review suggest that acupuncture is an effective treatment for animal PD models, but there is insufficient evidence to determine whether sex differences exist. Future studies of acupuncture treatment for PD should use female animal models because they reflect the physiological characteristics of both males and females to fully evaluate the effect and the safety of the treatment for each sex.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1405-5) contains supplementary material, which is available to authorized users.

A global call for action to include gender in research impact assessment

Global investment in biomedical research has grown significantly over the last decades, reaching approximately a quarter of a trillion US dollars in 2010. However, not all of this investment is distributed evenly by gender. It follows, arguably, that scarce research resources may not be optimally invested (by either not supporting the best science or by failing to investigate topics that benefit women and men equitably). Women across the world tend to be significantly underrepresented in research both as researchers and research participants, receive less research funding, and appear less frequently than men as authors on research publications. There is also some evidence that women are relatively disadvantaged as the beneficiaries of research, in terms of its health, societal and economic impacts. Historical gender biases may have created a path dependency that means that the research system and the impacts of research are biased towards male researchers and male beneficiaries, making it inherently difficult (though not impossible) to eliminate gender bias. In this commentary, we – a group of scholars and practitioners from Africa, America, Asia and Europe – argue that gender-sensitive research impact assessment could become a force for good in moving science policy and practice towards gender equity. Research impact assessment is the multidisciplinary field of scientific inquiry that examines the research process to maximise scientific, societal and economic returns on investment in research. It encompasses many theoretical and methodological approaches that can be used to investigate gender bias and recommend actions for change to maximise research impact. We offer a set of recommendations to research funders, research institutions and research evaluators who conduct impact assessment on how to include and strengthen analysis of gender equity in research impact assessment and issue a global call for action.

Balance of the Sexes: Addressing Sex Differences in Preclinical Research

Preclinical research is fundamental for the advancement of biomedical sciences and enhancing healthcare. Considering sex differences in all studies throughout the entire biomedical research pipeline is necessary to adequately inform clinical research and improve health outcomes. However, there is a paucity of information to date on sex differences in preclinical work. As of 2009, most (about 80 percent) rodent studies across 10 fields of biology were still conducted with only male animals. In 2016, the National Institutes of Health implemented a policy aimed to address this concern by requiring the consideration of sex as a biological variable in preclinical research grant applications. This perspective piece aims to (1) provide a brief history of female inclusion in biomedical research, (2) describe the importance of studying sex differences, (3) explain possible reasons for opposition of female inclusion, and (4) present potential additional solutions to reduce sex bias in preclinical research.

Sex/gender differences in the brain and cognition in schizophrenia

The early conceptualizations of schizophrenia have noted some sex/gender differences in epidemiology and clinical expression of the disorder. Over the past few decades, the interest in differences between male and female patients has expanded to encompass brain morphology and neurocognitive function. Despite some variability and methodological shortcomings, a few patterns emerge from the available literature. Most studies of gross neuroanatomy show more enlarged ventricles and smaller frontal lobes in men than in women with schizophrenia; finding reflecting normal sexual dimorphism. In comparison, studies of brain asymmetry and specific corticolimbic structures, suggest a disturbance in normal sexual dimorphism. The neurocognitive findings are somewhat consistent with this picture. Studies of cognitive functions mediated by the lateral frontal network tend to show sex differences in patients which are in the same direction as those observed in the general population, whereas studies of processes mediated by the corticolimbic system more frequently reveal reversal of normal sexual dimorphisms. These trends are faint and future research would need to delineate neurocognitive differences between men and women with various subtypes of schizophrenia (e.g., early versus late onset), while taking into consideration hormonal status and gender of tested participants.

Systematic review of the relationship between quick returns in rotating shift work and health-related outcomes

A systematic literature search was carried out to investigate the relationship between quick returns (i.e., 11.0 hours or less between two consecutive shifts) and outcome measures of health, sleep, functional ability and work-life balance. A total of 22 studies published in 21 articles were included. Three types of quick returns were differentiated (from evening to morning/day, night to evening, morning/day to night shifts) where sleep duration and sleepiness appeared to be differently affected depending on which shifts the quick returns occurred between. There were some indications of detrimental effects of quick returns on proximate problems (e.g., sleep, sleepiness and fatigue), although the evidence of associations with more chronic outcome measures (physical and mental health and work-life balance) was inconclusive.

PRACTITIONER SUMMARY

Modern societies are dependent on people working shifts. This study systematically reviews literature on the consequences of quick returns (11.0 hours or less between two shifts). Quick returns have detrimental effects on acute health problems. However, the evidence regarding effects on chronic health is inconclusive.

Effect of gender on clinical presentation in systemic lupus erythematosus

The incidence of SLE is markedly increased in females of child-bearing age. Although males are protected in terms of incidence of disease, it is unclear whether a distinct phenotype of male lupus exists in those who do develop SLE. We sought to explore through a detailed literature review whether gender exerts an influence on the clinical presentation and outcome of SLE. We found that males experience less of the typical mucocutaneous and musculoskeletal symptoms commonly present at diagnosis in women. On the other hand, there is limited evidence to support a negative prognostic association between male gender and disease activity or mortality.

Is there still gender bias in nursing research? An update

Data from 300 studies published in four research journals in 2010-2011 were analyzed to assess whether nurse researchers continue to oversample females. One-third of the studies had samples that were 100% female and, on average, 74% of all study participants were female. As was found for studies published 5 years earlier, the bias against male participants was consistent across studies differing in methods, specialty areas, funding, and sample characteristics. Studies with male first authors, however, were significantly less likely to have biased samples. Authors of only 23.6% of studies with mixed-sex samples provided information about sex differences in outcomes. Because of gender bias, the evidence base for nursing practice may suffer from problems with generalizability.

After inclusion, information and inference: reporting on clinical trials results after 15 years of monitoring inclusion of women

OBJECTIVE

The objectives of this report are to review the publications resulting from National Institutes of Health (NIH)-funded phase 3 trials monitored by NIH for inclusion and to address the quality of the research conducted and the validity of the sex/gender-specific or sex/gender difference analyses reported.

METHODS

For intervention trials enrolling both women and men, this review links reports to NIH of completed enrollment to publications of trial results. Each publication was then reviewed for a variety of reported characteristics based on established measures of quality, bearing on whether or not the research will permit valid analyses of sex/gender differences.

RESULTS

Publications from 268 trials reported an overall average enrollment of 37% (±6% standard deviation [SD]) women, at an increasing rate over the years 1995-2010. Only 28% of the publications either made some reference to sex/gender-specific results in the text or provided detailed results including sex/gender-specific estimates of effect or tests of interaction.

CONCLUSIONS

Efforts at including women in clinical research have increased the information captured relative to women's health. Sex/gender-specific information has been captured and should be available to other researchers for further analysis, including individual patient data meta-analyses. Improved reporting and disseminating sex/gender-specific results will allow sex/gender-specific inferences and healthcare decisions.

Differences in efficacy and safety of pharmaceutical treatments between men and women: an umbrella review

Being male or female is an important determinant of risks for certain diseases, patterns of illness and life expectancy. Although differences in risks for and prognoses of several diseases have been well documented, sex-based differences in responses to pharmaceutical treatments and accompanying risks of adverse events are less clear. The objective of this umbrella review was to determine whether clinically relevant differences in efficacy and safety of commonly prescribed medications exist between men and women. We retrieved all available systematic reviews of the Oregon Drug Effectiveness Review Project published before January 2010. Two persons independently reviewed each report to identify relevant studies. We dually abstracted data from the original publications into standardized forms. We synthesized the available evidence for each drug class and rated its quality applying the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Findings, based on 59 studies and data of more than 250,000 patients suggested that for the majority of drugs no substantial differences in efficacy and safety exist between men and women. Some clinically important exceptions, however, were apparent: women experienced substantially lower response rates with newer antiemetics than men (45% vs. 58%; relative risk 1.49, 95% confidence interval 1.35–1.64); men had higher rates of sexual dysfunction than women while on paroxetine for major depressive disorder; women discontinued lovastatin more frequently than men because of adverse events. Overall, for the majority of drugs sex does not appear to be a factor that has to be taken into consideration when choosing a drug treatment. The available body of evidence, however, was limited in quality and quantity, confining the range and certainty of our conclusions.

International gender bias in nursing research, 2005-2006: a quantitative content analysis

AIM

This paper reports a study that examined the extent to which nurse researchers internationally disproportionately include females as participants in their research.

BACKGROUND

A bias toward predominantly male samples has been well-documented in medical research, but recently a gender bias favoring women in nursing research has been identified in studies published in four North American journals.

METHOD

We extracted information about study samples and characteristics of the studies and authors from a consecutive sample of 834 studies published in eight leading English-language nursing research journals in 2005-2006. The primary analyses involved one-sample t-tests that tested the null hypothesis that males and females are equally represented as participants in nursing studies. Studies from different countries, in different specialty areas, and with varying author and methodologic characteristics were compared with regard to the key outcome variable, percent of participants who were female.

RESULTS

Overall, 71% of participants, on average, were female, including 68% in client-focused research and 83% in nurse-focused studies (all p<.001). Females were significantly overrepresented as participants in client-focused research in almost all specialty areas, particularly in mental health, community health, health promotion, and geriatrics. The bias favoring female participants in client-focused studies was especially strong in the United States and Canada, but was also present in European countries, most Asian countries, and in Australia. Female overrepresentation was persistent, regardless of methodological characteristics (e.g., qualitative versus quantitative), funding source, and most researcher characteristics (e.g., academic rank). Studies with male authors, however, had more sex-balanced samples. The mean percentage female in client-focused studies with a female lead author was 70.0, compared to 52.1 for male lead authors.

CONCLUSION

Nurse researchers not only in North America but around the globe need to pay attention to who will benefit from their research and to whether they are adequately inclusive in studying client groups about which there are knowledge gaps.

Women, psychosis and violence

Psychosis confers a disproportionate risk of violence on women compared with men, but such women barely affect national crime statistics anywhere. Much research in the field does not include women at all. In our literature review, we found that information about women, psychosis and violence generally had to be extracted from studies including women but focussing on men; not uncommonly analyses 'controlled for gender' rather than treating it as interesting in itself. A tendency for women to be older than men at onset of psychosis may not apply to those who become violent, but women with psychosis do seem to start offending later and desist sooner. Rates of seriously adverse childhood experiences are similar between women and men with psychosis, except for sexual abuse-more frequently reported by the women. Some evidence of special patterns for women in the nature of psychosis and violence relationships requires more exploration, as do treatment questions. With so few women in any one service, multi-centre co-operation in research with them will be essential.