The healthy behaviours and COVID-19 mortality among Iranian women: a case–control study

Since late 2019, the new human coronavirus, Coronavirus disease 2019 (COVID-19), was initially reported in Wuhan, China, and spread rapidly all over the world, and has now become a pandemic and an international health concern. It has had many human, economic, and social consequences [1]. Globally, the number of people infected with COVID-19 has reached to more than 178 million out of which more than 3.8 million were died due to this outbreak untile June 19, 2021. From the reports, twelve countries included United States, India, Brazil, France, Turkey, Russia, Britain, Italy, Argentina, Colombia, Spain, and, Germany bear more than 3.5 million confirmed cases of COVID-19 [2]. In Iran, out of 3.03 million individuals infected by COVID-19, 82 thousand people lost their lives [3].

The reports on the COVID-19 infected groups in most countries, including Iran showed that twice as many men as women are susceptible to COVID-19 [4]. The rate of mortality of men in New York was twice as that of women while it was 70% and 63% higher in China and Europe, respectively [5]. In Iran, based on the national statistics on the patients admitted to COVID-19 hospitals, 63% were men while women constituted 37% [6].

Although, all people of the community, from young to old and men and women, are at risk of COVID-19, age, and sex are two critical factors influencing the incidence or severity of the symptoms. The incidence and severity of COVID-19 in men is affected by a number of factors, as identified via various global studies, including biological factors e.g., genetic, hormonal, and enzymatic factors, plus social profile, job, and additional economic responsibility of men. These factors together with cultural perspectives such as misconceptions of men for being superior and more robust than women, forge them to pay little attention to their health, fail to care for attending medical centres, doing test, and comply with hygiene principles of frequent hand washing, wearing masks and gloves [7‐11]. Collectively, these factors put men at higher risk of infection and fatality due to COVID-19.

On the other hand, chronic diseases such as cardiovascular disease (high blood pressure, diabetes, coronary heart disease, and cerebrovascular disease) are also more common in men than women, resulted from the unhealthy behaviours such as inactivity, unhealthy diet, and smoking which are comparatively prevail in men [12].

In most parts of the world, men are more likely than women to develop Covid-19 and experience a more severe illness, so most studies have focused on men to identify the most important contributors to Covid-19 mortality and morbidity. On the other hand, the incidence rate of Covid-19 in Ardabil, as one of the provinces of Iran, unlike other parts of the world, was higher in women than men. On the other hand, according to the COVID-19 dashboard in Iran, more than 63% of Covid-19 patients in Ardabil province are women. Considering that there is no known reason for the higher incidence of Covid-19 in men or women around the world, as Covid-19 is an unknown virus with unpredictable effects and may change the incidence rates of Covid-19 by sex in the future in other parts of the world. Therefore, this study is designed to identify the most important risk factors for COVID-19 among women with Covid-19 and healthy women to ultimately provide policies specific to women to prevent and control Covid-19. Considering the contradiction between the Ardabil province and most parts of the world in higher prevalence of COVID-19 among women than men, this study aimed to investigate the healthy behaviours in women of Ardabil and its relationship with COVID-19 mortality.

The case and control groups' results in terms of demographic variables and underlying chronic diseases are presented in Table 1. According to the results, the mean age of the case group was 54.57 ± 21.60 years, and the mean age of the control group was 43.80 ± 13.97 years. The groups showed a significant difference in mean age. As per results, 64% of women with COVID-19 had an underlying chronic disease from which the most common diseases belonged to the patients with cardiovascular disease. The lowest frequency in both groups belonged to the patients with metabolic diseases. There was a significant difference between the two groups in terms of distribution and prevalence of underlying chronic diseases (p < 0.05). The patients' overall smoking rate and healthy individuals were about one percent, and the studied groups did not differ significantly in this regard. Pursuant to the results, the prevalence of obesity and being overweight in the case group was significantly higher than that of the control group.

The status of compliance with health behaviours and protocols in the two groups is provided in Table 2. Regarding communication and travel history, the results showed that the group of women with COVID-19 had a significant (8.8%) history of especially travelling to high-risk areas (2.3%), contact with the medical staff (2.7%). The 12.6% of patients with COVID-19 contacted familiar patients, wherein it was null in the case of healthy women (p < 0.05). In accordance with the results, women with COVID-19 used significantly less masks and gloves than control group (49.4% vs. 65.4%) and (30.7% vs. 38.9%) during the last 14 days, respectively. The results did not show a significant difference between the two groups in terms of traffic history to different places, including hospitals and health centres during the COVID-19 period.

One of the main studied factors was the rate of mortality due to COVID-19 in reference to age and underlying chronic diseases (Fig. 1). From the results, the highest mortality occurred in individuals with underlying chronic diseases in the age group over 80 years. Moreover, from the women with coronary heart disease who died of COVID-19, the highest frequency belonged to the age group over 80 years. However, the women with diabetes, obesity, and underlying chronic diseases who died with COVID-19 were in the age group of 50–80 years. Significant differences were found between the age groups in terms of mortality due to underlying chronic diseases.

Based on the results provided in Table 3, the mortality rate was significantly increased with age among the women affected by Covid-19. The mortality rate of women above 80 years old was 8.97 times (95% CI 2.27–29.85) higher than that of women under the age of 30. In the case of the women with underlying chronic diseases, the mortality rate was 4.14 times (95% CI 1.61–10.64) more than that of women without chronic diseases. This also applies for the diabetes (1.44, 95% CI 1.61–10.64), cardiovascular disease (1.82, 95% CI 1.09–2.89), and obesity (2.95, 95% CI 1.26–6.89). By reason of low smoking rate and no fatality among the smoker female, this variable was eliminated from the model. Besides, there was no report of mortality in women under 30 years old group, which accordingly was eliminated from the model. As per results, the increase in body mass index, boosted the mortality rate in women with COVID-19 wherein fatality in obese women with COVID-19 was 3.01 times (95% CI 1.04–6.03) more than the died women with normal weight.

The universal information on gender-related COVID-19 case fatality is rather controversial, and there is no general trend in different regions. Whilst, most countries reported higher fatality rates for male than female [13], the female to male case fatality rate is also higher in some instances [14]. Rozenburg etal. Showed that men are almost 60% more likely to be seriously sick or to kick the bucket from the complications of Covid-19 than are women [15]. Against the backdrop of global data, men are biologically and behaviourally at higher risk of sickness and death caused by COVID-19 [16]. In spite of the fact that within the widespread men die more regularly than women from Covid-19, it isn't clear whether typically due to biological differences between men and women, differences in behavioral habits, or differences within the rates of co-morbidities [15]. Nonetheless, prevalence of COVID-19 among women in Ardabil province was higher than men and the case illness and fatality were respectively 7.2% and 2.6% more than men (end of December 2020).

Large number of studies have been conducted all over the world to determine various factors, which increase the risk of infection and mortality by COVID-19. Taking into account that some factors are universally supported, higher COVID-19 infection and fatality rate of women in Ardabil province, against the global norm, brought about the involvement of some other factors. This study provided the first comprehensive assessment of the effect of healthy behaviours (contact and travel history, observance of health protocols, and presence in different circles and places during 14 days) and demographic factors (age, place of residence, underlying chronic disease (diabetes, cardiovascular, lung diseases, metabolic diseases), and obesity, and smoking) on the rate of COVID-19 case illness and fatality of female in Ardabil province. As per results of this study, significant differences were found between the healthy and infected women in terms of healthy behaviours such as the history of contact and traveling, wearing mask, going to work place, and attend public gatherings, in connection with the surveyed demographic factors, except for smoking habit. Pope etal. found that among pregnant women, some pandemic-related behaviours (avoiding public places and wearing masks) were higher than other population groups during Covid-19 pandemic [17]. Barber etal. reported that women in compare with men had higher worry and the more consideration of health behaviours against Covid-19 [18].

From the results, the risk of illness and fatality of women due to COVID-19 was increased by age. The age-dependency of patients was found significant as compared to healthy individuals. The results of the present study on the mortality age distribution as a result of COVID-19 infection (odd ratio = 8.97 in women above 80 years old) was found similar to other studies. For further details, the rate of fatality in Spain, Japan, Italy, and China was the most at the ages above 70 [13, 19, 20]. As per data on average age of female in Ardabil province (as of 2016 census results), it was older compared with that of male in Ardabil province (31.5 vs. 30.9) and Iranian female in general (31.5 vs.31.3) [21]. However, as the years pass, the increase in the gap between the average age of male and women in Iran has been estimated, thus resulting in higher percentage of older women to men. Accordingly, the age-dependent susceptibility to COVID-19 resulted in higher fatality of female of Ardabil province.

The other risk factor of mortality by COVID-19 is to being subjected to non-communicable diseases (NCDs). The individuals underlying NCDs such as cardiovascular disease (CVD), diabetes, hypertension, and chronic respiratory disease are at great risk of death by COVID-19. Therefore, it is vital for people living with NCDs to properly manage their diseases, avoid unhealthy life-style risk factors (e.g., smoking, obesity, and alcohol), and more importantly, obey basic protective measures with respect to COVID-19. Since, the patients with NCDs are more likely to die of the current pandemic, a special care has been devoted to diminish the risk of COVID-19 infection of those suffering from NCDs. From the results of this study, among the patients with NCDs, a large proportion of the study cases suffered from chronic diseases and with CVD accounted for approximately half of the female with COVID-19. Due to somehow lifelong nature of these diseases, the women with chronic and cardiovascular diseases have to approach hospitals and healthcare centres on a regular basis. Hence, they are at higher risks of infection under COVID-19 epidemic. The reports are replete with significantly higher rate of fatality under COVID-19 and NCD synergistic pandemic, syndemic, which is especially of concern for low-income and marginalised individuals who undergo economic and social inequalities and usually do not access proper health services [22]. However, the lack of awareness and some other factors that were taken into account in this study, have roles in susceptibility to infection by COVID-19 and the worst consequences. For instance, more than half of the women hospitalised with CIVID-19 were in contact with unknown resources and one third had travelled outside their residence place, and contacted familiar patients and patients before diagnosis of their illness. This have increased the likelihood of infection and death of the study case group by the time control group strictly followed the cautions and rarely attended dangerous or risky people/places.

On the other hand, the cases with obesity and diabetes devoted 40.6% and 36% of infected female while lung and metabolic diseases accounted for small number of cases. The above-mentioned causes are comparable for all individuals with NCDs and exposed them to higher risks of COVID-19 infection and death. However, obesity is one of the influential factors that puts people at higher risks of infection and fatality by this global pandemic, regardless of their age [23]. The change in immune function of body in obese people has been well-documented [24]. The risk is gradually grown as the body mass index (BMI) increases [23, 25]. In this study, more than 40% of case group were obese, which was significantly higher than control group. In a larger scale, the prevalence of obesity in female of Ardabil province is higher than the average in Iran [26]. Consequently, obesity can be assumed as one of the leading factors of higher rate of female fatality due to COVID-19 in the studied case group. It should be pointed out that the habit of smoking was negligible among the case and control groups and was not accordingly assessed as a potential factor.

Together with the discussed causes, a number of behaviours boosts the susceptibility of infection with COVID-19, if not conducted. Among the studied case and control participants, wearing mask and gloves and implementation of disinfectants in the last 14 days were questioned as of the important healthy behaviours restricting the chance of infection. Practically, a significant difference was found between the case and control groups in wearing mask and gloves. However, slightly more than half of the case group participants remarked the application of disinfectants, which was comparable with control group. Therefore, the faulty implementation of health protocols by case group could be another cause factor of women infected with COVID-19. These protective measures have been extensively emphasised by government authorities and health organisations as primary factors to reduce the spread of infection [27].

In conclusion, the higher rate of the fatality of women in Ardabil province due to COVID-19 could be resulted from the older average age, the prevalence of obesity, and failure in following the protective measures and healthy behaviours. The most important issue regarding the higher rate of the fatality of women in Ardabil province due to COVID-19 can be more health behaviors, including participation in gathering and also having underlying chronic diseases. Some other factors such as incomplete data on individuals affected by COVID-19 across rural areas and far regions, effect of some other demographic and/or socio-economic factors, which put women at higher risks of mortality due to COVID-19.

Future studies should be designed and conducted in order to support the health of women living with NCDs especially during the pandemic. The priority in vaccination should be given to more vulnerable groups including old people and patients with NCDs and obesity. Special emphasis should be given to the increase of women awareness on the importance of healthy diet and life-style. The role of physical activity and maintaining the mental health of women during outbreak should be also taken into account.