Eight studies reported differences between the accuracy of diagnostic tests for TB among males and females (10, 13, 15, 25, 26, 28, 31, 33). Across the studies, the main causes of sex/gender differences in TB diagnosis were noted as the quality of specimens, use of less sensitive methods such as Ziehl-Neelsen for detecting acid-fast bacilli instead of molecular tests like Xpert Mycobacterium tuberculosis (MTB)/rifampicin (RIF) (10, 25, 26, 28, 31), and delay in specimen submission (15).

One study of individuals with suspected TB at an urban clinic in Nairobi, Kenya identified that females are more likely to produce suboptimal specimens (31). Other studies noted that there is anecdotal evidence that women are less likely to provide good-quality sputum, leading to a lower yield from smear microscopy (10).

A study from Myanmar reported sex-based differences in the diagnosis of rifampicin-sensitive and resistant TB using the Xpert MTB/RIF assay, with male patients more likely to test positive than females (47% vs. 39%) (33). Female patients also had a slightly higher proportion of rifampicin resistance (11·4%) than males (9·3%), although no reason was given for this difference (33).

Males are found to have a bias towards having sputum smear-positive pulmonary TB (13). Data from a large UK TB study were used to evaluate whether the immune response bias was important in terms of diagnosis or the ability to predict the onset of disease in persons exposed to TB. Females with sputum smear and culture-positive TB were found to have stronger tuberculin responses, whereas weak responses were seen in those who were screened for TB but did not develop the disease (13). Contrastingly, males had higher interferon-gamma responses than females to TB antigens ESAT-6 and CFP-10 (13).

In Concept 2, 17 studies reported differences between healthcare-seeking behavior among male and female TB patients (9, 10, 16, 17, 19–22, 24, 26–31, 34, 36). Key causes noted as contributing to the differences between male and female healthcare-seeking behaviors included that women may seek healthcare much later than men resulting in delayed diagnosis of TB (20, 24, 29, 36) and that women are less likely to report cough and TB symptoms (28). In addition, healthcare-seeking behavior among women can be associated with social stigma (34). Another study from India reported that more females (58%) were scared than men (50%) while disclosing TB symptoms (30). A study from India also reported that more women (71%) than men (69%) utilized general healthcare and took self-treatment for TB symptoms (19). In Peru, Onifade et al. reported that women generally do not seek clinical investigations like X-rays and TB diagnostic tests due to a lack of money (29).

Furthermore, studies reported differences in where women seek care. Two studies noted that women are more likely to visit private clinics than men (16, 22). An assessment of health-seeking behavior in Indonesia found that women were more likely to seek care in private primary clinics compared with men, who opted for Level 0 pharmacy visits (16). A study conducted in Alexandria, Egypt, reported that more women than men had attended a private clinic for the diagnosis of TB (28·8% versus 14·7%) (22). Further, a study from China reported that women are more likely than men to visit the village clinic (49·1% vs. 44·6%, respectively) and local drug store (17% vs. 8·9%, respectively) (36).

Gender/sex-based barriers to accessing diagnosis and care for TB were reported in 25 studies (8, 9, 11, 12, 14–23, 25–32, 34–36). Some studies noted that TB is associated with greater social stigma for women versus men (14, 17, 27, 34, 35). Females may also face barriers to accessing healthcare generally, because more women than men have limited finances, may be dependent on family members, and have a limited role in family decision-making (15, 29, 35). Household responsibilities and childcare can also lead females to receive delayed healthcare services (29, 35). Females may also have less awareness of TB than males, due to lower levels of education and access to information sources like television and radio (11, 17, 30).

However, one study of gender differences among TB patients in Guinea-Bissau found that although more women sought help for symptoms of pulmonary TB, more men were diagnosed. As women did not have more clinically severe diseases than men and did not drop out of diagnostic testing, the authors conclude that the gender gap is unlikely to be solely a result of differences in care-seeking behavior or diagnostic procedures in this setting (12).

In terms of specific populations, females from rural areas are more likely to receive delayed healthcare services (15), as are younger and divorced/separated women (23). Women may also be unable to produce sputum in front of male doctors or are less likely to be offered sputum test (35).

Three studies reported implicit biases of healthcare providers based on sex or gender (28, 29, 35). A study of gender-related factors associated with delayed TB diagnosis in Eastern Europe and Central Asia identified that women in Georgia, Kazakhstan, and Tajikistan deprioritized seeking diagnosis for TB because of their lack of access to financial support, and obligations to care for family and young children (35). The study was also provided insights from gender-diverse people in Georgia, who reported stigmatization by health service providers in medical institutions (35). In Uganda, clinicians refer fewer female patients than males for acid-fast bacilli testing for the diagnosis of TB (28). In addition, the study in Peru identified that both patients and healthcare workers commonly believe that women’s health inherently has a lower priority than men’s health (29).

A mixed-methods assessment in the US found that men had 19% higher odds (95% CI:1·09–1·30) of being screened for prediabetes than women, possibly due to the higher prevalence of hypertension (a consideration for screening) among men (37).

A cross-sectional study in Germany identified that quality of care for patients with type 2 diabetes is influenced by the gender of the physician (39). Women physicians were found to provide an overall better quality of care, especially in prognostically important risk management (39).

A study of sex-related psychological differences in type 2 diabetes mellitus found that females reported lower satisfaction with social support. However, females on oral hypoglycaemic drugs were better informed about type 2 diabetes than males (38). Gender differences were also found across various quality-of-care measures for diabetes. Both men and women with diabetes were found to have quality-of-care deficits. Still, women generally reported lower quality of care than men among most measures for cardiovascular disease and diabetes.

A retrospective analysis of 1700 participants across eight studies conducted in Tanzania between 2010 and 2016 found decreased sensitivity of egg microscopy in women (41). In HIV-noninfected women and men, egg microscopy had a sensitivity of 38 and 62%, respectively (38% versus 62% difference, p < 0·001) and in HIV- for Schistosoma infection (41). This finding was maintained, although smaller, among HIV-infected individuals (egg microscopy sensitivity of 33% in women versus 41% in men, p = 0·23) (41).

A study analysing f self-reported urinary schistosomiasis in school children from Tanzania found that the specificity of self-reported schistosomiasis was 100% in older girls, indicating correct self-diagnosis by all uninfected girls (42). However, the sensitivity of self-diagnosis among girls was lower, with results showing incorrect self-diagnosis more often by infected girls than infected boys. In addition, infected older girls were more likely to report their infection status incorrectly than infected younger girls (42).

One article reported work to train healthcare workers on how to improve the prevention, diagnosis, and treatment of female genital schistosomiasis (FGS) (43). Virtual workshops were held to establish standardized skills across the continuum of care for FGS, including for prevention diagnosis and management (43).

A study of schistosomiasis-related perceptions, attitudes, and treatment-seeking practices in Tanzania identified social stigma associated with various manifestations of schistosomiasis (44). Boys, girls, and adults were noted as being shy to tell parents and doctors of their symptoms because of shame, fear of disclosure to others, and the association with promiscuity (44). Another study highlighted low awareness of the disease in Sub-Saharan African communities and health systems, which acts as a barrier for women in terms of addressing the symptoms and complications associated with FGS (43).

A qualitative assessment of knowledge gaps around FGS among communities in endemic districts of Zanzibar and mainland Tanzania identified that most participants, male and female, lacked knowledge of FGS (45). Most participants also reported a lack of knowledge that urogenital schistosomiasis can affect female reproductive system (45). Adolescent girls and women with symptoms of FGS were reportedly stigmatized and perceived as having a sexually transmitted disease (STD) (45).

Another study conducted an epidemiological and socioeconomic analysis of FGS across eleven rural fishing communities in Cameroon (46). The study identified that inadequate diagnostics and treatments for FGS are major causes of suffering among women and girls with the condition, and instead often mistreated for STDs and other infections (46).

In Tanzania, healthcare professionals stated that their services, whether they were focused on modern or traditional medicine, were complementary to one another (44). Traditional healers mostly with abdominal and infertility problems among women (44).

Another study highlighted the common cycle of FGS misdiagnosis and treatment, where women with symptoms are presumptively treated for STDs (43). When the woman’s symptoms do not resolve, healthcare workers may assume non-compliance or re-infection and the woman will be asked to repeat treatment (43). Eventually, the woman may be referred to the next-level health centre, where she may receive additional examinations, but will likely receive next-line treatment for STDs (43). Each step of the cycle results in financial and opportunity costs for women, and more time spent with untreated FGS and its complications (43).

Countries, in which females face more discrimination within families and have limited access to resources, education, and finance, report greater gaps between male and female rates of COVID-19 positive cases and mortalities (47, 48). A retrospective study of COVID-19 sex-disaggregated data from 133 countries found that although most countries tend to report approximately equal COVID-19 infection and death rates for men and women, certain countries reported far higher case rates among men. For example, the proportion of confirmed COVID-19 cases that are men is 88% in Bahrain, 85% in Qatar, 75% in Saudi Arabia and South Sudan, 74% in Pakistan, and 71% in Bangladesh (47). However, some countries report a slightly higher proportion of COVID-19 cases among women, including Ukraine, Moldova, Poland, Latvia, Jamaica, Georgia, and Armenia (47).

Another analysis of sex-segregated COVID-19 data for 72 countries suggests that countries with institutionalized gender disparities and poor healthcare access and quality tend to have higher male-to-female (M: F) ratios of confirmed COVID-19 cases. In the study, Cambodia had the highest M: F ratio of confirmed COVID-19 cases (4.08:1), followed by Pakistan (M: F = 2·85:1) and Nepal (M: F = 2·69:1) (48). The study also identified a positive correlation between the gender inequality index and M: F ratio (Spearman’s rho = 0·681, p < 0·001) and a negative correlation between healthcare access and quality index and M: F ratio (Spearman’s rho = −0·676, p < 0·001) (48).

A study using the Dutch Lifelines COVID-19 Cohort (N = 74,722; 60·8% female) found no sex-related disparities in COVID-19 testing and diagnosis in the general population. However, among healthcare workers, females were less often diagnosed and tested than males (odds ratio = 0·54; 95% CI, 0·32–0·92 and odds ratio = 0·53; 95% CI, 0·29–0·97, respectively) (49).

People who identify as lesbian, gay, bisexual, transgender, or queer and questioning (LGBTQ+) confront numerous health inequities, which may increase their vulnerability to COVID-19 compared with the general population. In a nationwide survey of COVID-19 testing in LGBTQ+ populations in the United States, of the 1,090 participants, 182 (16·7%) had received a PCR test, with 16 (8·8%) receiving a positive result (50). Across the surveyed population, antibody testing rates were greater among gay cisgender men (17·2%) versus other sexual orientation and gender identity groups, non-US-born (25·4%) versus US-born participants, employed (12·6%) versus unemployed participants, and Northeast (20·0%) participants versus other regions (50). For PCR testing, positive PCR results were highest among cisgender gay males (16·1%) among sexual orientation and gender identity groups with sufficient numbers for comparison (50). The authors note that the disparities in testing and positivity, notably among gay males in this sample, highlight the importance of developing COVID-19 public health messages and programming for the LGBTQ+ population (50).

In a national online survey of US adult individuals belonging to sexual and gender minority groups, transgender and bisexual/pansexual people reported being more interested in a COVID-19 vaccine and an at-home test than cisgender and gay/lesbian respondents (51). Respondents who endorsed having intersex traits and people living with HIV were both less likely to be interested in an at-home COVID-19 test than those who did not endorse intersex traits or people living without HIV, respectively (51). These findings highlight critical differences in COVID-19 symptomology and prevention behaviors among sexual and gender minority groups, which should be considered when designing effective COVID-19 interventions (51).

A study of the prevalence and correlates of COVID-19 testing in an online sample of transgender and non-binary people (n = 536) discovered that certain identities were significantly more likely to test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (52). Transgender and non-binary individuals from upper socioeconomic income backgrounds and Europe who reported active alcohol use disorder, limited access to gender-affirming surgery, income reduction of more than 20%, and mistreatment in a health facility due to gender identity had significantly greater probabilities of COVID-19 testing (all p < 0.05) (52).

A population-wide cohort study of all residents of Ontario, Canada, who received a nasopharyngeal swab for SARS-CoV-2 between 23 January 2020 and 26 May 2020 looked at sex- and age-specific differences in COVID-19 testing, cases, and outcomes (53). Except two age groups (ages 0–9 years and 70–79 years), males received less COVID-19 testing than would be expected for their age-based representation in the Ontario population (53). For those with COVID-19 infection, males also had higher rates of hospitalization (15·6% vs. 10·4%), intensive care unit (ICU) admission (4·1% vs. 1·7%), and death (8·7% vs. 7·6%) than females; these findings were consistent even when adjusting for age (53).

A cross-sectional analysis of data from a COVID-19 Surveillance and Outcomes Registry from the US reported that males were significantly more likely to test positive for COVID-19 (17.0% in males vs. 14.6% in females, odds ratio 1:20) (54). Irrespective of age, among hospitalised patients, males were more likely than females to experience medical complications, need ICU admission and mechanical ventilation, and have higher death rates (54).

A study of the factors affecting household choice of malaria treatment options in Ghana found that women from Hohoe (a rural area) were more likely than men to seek treatment for malaria from a public health care provider (55). Whereas, a study in Vietnam reported that the delay between first symptoms and seeking healthcare was significantly longer among female patients (median 3 days) compared with male patients (median 2 days; p < 0·001) (56).

In Uganda, a study of gender differences in the incidence of malaria at 12 public malaria reference facilities found that women were significantly more likely than men to report fever in the previous two weeks and seek care at local health centres (7·5% vs. 4·7%, p = 0·001) (57). However, female gender was also associated with a higher incidence of visits where malaria was not suspected (IRR = 1·77, 95% CI 1·71–1·83, p < 0.001) (57).