Sex- and age-disaggregated data are a prerequisite for an effective response
The scarcity of disaggregated data is not new. In the past, in the context of diseases with a greater burden in low-income countries, such as the HIV epidemic, the lack of resources and capacity, coupled with poor health information systems, has been invoked for not collecting or reporting sex-disaggregated data. However, countries at the epicentre of the COVID-19 pandemic are mostly high-income countries with advanced and robust health information systems, which undoubtedly collect data on sex and age in electronic medical records yet fail to analyse or report the data in terms of gender.
As affirmed by WHO’s Director-General in opening the Seventy-third World Health Assembly (WHA) in May 2020, ‘The world does not lack the tools, the science or the resources to make it safer from pandemics. What it has lacked is the sustained commitment to use the tools, the science and the resources it has.’12 In addition, most if not all affected countries are WHO Member States which in 2007 adopted the resolution WHA60.2513 whereby they committed to collect and analyse sex-disaggregated data, while undertaking research to understand factors that contribute to gender disparities in order to use the evidence to inform policies and programmes.
Lack of continuous monitoring of sex- and age-disaggregated data limits the effectiveness of pandemic responses. Early data from China and other preliminary analyses indicate that men are at greater risk of death from COVID-19 than women are, as explained by higher prevalence of smoking and comorbidities among men and a stronger biological immune response in women.14 While this continues to hold true in many countries, the paucity of sex- and age-disaggregated data and the observed variability across countries warn against early assumptions.
Mounting data reveal notable geographical variability that merits further investigation in order to understand the extent of, and reasons for, gender differences across age groups and locations. In the Republic of Korea, a country with higher detection rates, more women than men were reported as infected with COVID-19 (54.72% of women vs 45.28% of men). A similar picture can be observed in Spain with recent data showing more women being infected (51.2% of women vs 48.5% of men).15 In Italy, a similar trend can be observed (53% of women vs 47% of men) with some variations across age group.16
Despite variations in the male-to-female infection ratio, data continue to suggest higher case fatality rates1 among men compared with women in most of the countries and in most age groups, with a few exceptions. However, the size difference varies greatly. In the Islamic Republic of Iran, the difference in reported death rates among women and men with confirmed cases seem to be much smaller (12% higher in men than in women) than that in Spain (73% higher in men than in women)2. Finland and Pakistan report a slightly higher case fatality rate for women compared with men.17 These variances are probably due to a combination of factors, including transmission patterns, immunological differences, variability in prevalence of comorbidities or other risk factors (such as smoking and exposure to higher levels of air or household pollution), frequency of exposure and the viral load—but also the rate of and access to testing and case detection.
Infection and fatality rates across genders and age groups may also change over time as the pandemic evolves. Is it possible that there has been a time lag in infections in women, shaped by patterns of social mobility, international travel and transmission patterns? If this is the case, as is indicated by the preliminary data from Spain (from 78% of men vs 22% of women infected by 28 February,18 the rates of infection had changed to 48.5% vs 51.2%, respectively, by 20 August15 we may expect that the gender differences in infection and death rates may possibly change as the pandemic matures. This is probable given the increase in infections among healthcare workers, most of whom are younger women.
In Italy, by mid-March, approximately 20% of healthcare workers were infected with the virus. Data from Italy, Germany, Spain and the USA show that women account for 60%–70% of confirmed cases among healthcare workers. Evidence from Spain also shows that women are more exposed through contact with COVID-19-infected persons or by visiting health centres, resulting from their excessive caregiving responsibilities or as a result of being healthcare workers. Since the start of the outbreak in Spain, 35 548 cases of COVID-19 were confirmed in health workers by 7 May, of which 76% were women with median age of 46 years.19 The heightened vulnerability of women on the frontlines has been underscored by reports of gender blindness and bias in health systems—such as ill-fitting personal protective equipment designed for the male anatomy.20
We also have insufficient public data to rule out potential differences in symptoms and in the presentation of disease in women and men which may result in potential underdiagnosis or misdiagnosis. Data from other disease areas, such as cardiovascular diseases, have revealed that women and men may display differential symptoms that lead potentially to missed diagnosis or missed opportunities to seek care. Anecdotal data indicate that certain COVID-19 symptoms may be more common among men or, indeed, among women (eg, sore throat, vomiting and diarrhoea could be more common in women, whereas fever, breathing problems and pneumonia could be more frequent in men, as reported by Spain on 13 and 20 March 2020). While the data are too limited to draw any meaningful conclusions, there is a need for better gender analysis in order to have a more accurate understanding of clinical features, severity of disease, risk factors for infection and transmission patterns among women and men at different ages and in different settings.
