The mean age in the study population was 68 years (age range 50-104 years). Among the 73,274 individuals, 43.3% were men and 56.7% were women. The study population was distributed with 11.0% in Northern Europe, 25.5% in Western Europe, 20.7% in Southern Europe and 42.4% in Eastern Europe (Supplementary Table 1). Among the underlying medical conditions less than one percent of data were missing except from obesity, where 3.7% were missing (not shown in table).
In total, 75.3% of the study population had at least one risk factor for severe COVID-19, 45.9% had at least two factors and 21.2% had at least three factors. Overall, the prevalences for the risk factors were similar between European regions, except for higher prevalences in Eastern Europe (Table 2 and Supplementary Table 2). Prevalences of risk factors showed only minor differences for men across the European regions, whereas women in Eastern Europe had higher prevalences of risk factors compared with women in North, West and South (Table 2 and Supplementary Table 2). No sex differences were found in the overall prevalences of having at least one, two and three risk factors in Northern, Western and Southern Europe except for a lower prevalence of at least one risk factor for women than men (74.2% vs 76.1%) in Southern Europe. In Eastern Europe, higher prevalences of having one, two and three risk factors were found for women than for men (79.6% vs 74.1%, 53.5% vs 46.2% and 26.6% vs 22.1%, respectively). Overall, more women than men were 65 years and above (53.8% vs 47.5%), and women had lower prevalences of lung disease (5.2% vs 6.1%), cardiovascular disease (12.0% vs 16.0%) and diabetes (12.4% vs 14.4%) than men (Table 2 and Supplementary Table 3).
When mapping the prevalences of risk factors in the 26 European countries (Figure 1), we found that the prevalence of having at least one risk factor ranged from 62.4% in Slovakia to 82.7% in Hungary; having at least two factors ranged from 33.5% in Slovakia to 57.7% in Hungary; and having at least three risk factors ranged from 13.5% in Slovakia to 29.2% in Czech Republic (Figure 1). For women, the highest prevalences of risk factors were found in Eastern Europe, with Hungary (83.5%), Lithuania (83.1%) and Latvia (82.8%) having the highest prevalences of at least one risk factor, and Lithuania (59.0% and 31.1%), Estonia (55.6% and 28.5%) and Latvia (55.0% and 30.1%) having the highest prevalences of at least two and three risk factors, respectively. For men, a less consistent pattern was found. The highest prevalences of having at least one risk factor were found in Portugal (86.8%), Malta (86.6%) and Czech Republic (83.1%), the highest prevalences of having at least two factors were found in Czech Republic (59.8%), Hungary (52.8%) and Malta (51.0%) followed by Spain (50.7%) and Finland (50.1%), and the highest prevalences of having at least three factors were found in Czech Republic (31.8%), Hungary (26.0%) and Malta (25.4%) (Figure 1 and Supplementary Table 4).
The overall prevalence of the underlying medical conditions in the total sample was 41.4% for hypertension, 5.6% for chronic lung disease, 13.8% for cardiovascular disease, 4.5% for cancer, 13.3% for diabetes and 21.4% for obesity, but varied between European regions (Table 2). The most pronounced differences between regions were found for Eastern Europe. Compared with Northern and Western Europe, Eastern Europe had higher prevalences of hypertension, cardiovascular disease, diabetes and obesity, but lower prevalences of lung disease and cancer. Compared with Southern Europe, Eastern Europe had higher prevalences of hypertension, cardiovascular disease and obesity (Table 2 and Supplementary Table 2).
Overall, the prevalences of having at least one, two and three risk factors increased with age until the age group 80-89 years but decreased thereafter. Also, the prevalence of each medical condition generally increased with age; however, the prevalences of obesity increased until age 60-69 years, were overall stable until age 80-89 years, and decreased thereafter (Table 2 and Supplementary Table 5).
When estimating the prevalences of risk factors without age as an underlying factor, the overall prevalences of having at least one, two and three risk factors decreased to 60.3%, 27.9% and 9.5%, respectively (Supplementary Table 6).
Given the prevalences found in the SHARE population, we estimated that the number of individuals having at least one of the risk factors for severe COVID-19 in the European population was about 131 million persons (70,672,673 women and 60,104,205 men). Almost 80 million persons (42,592,064 women and 36,253,330 men) had at least two risk factors and almost 37 million persons (20,165,269 women and 16,695,613 men) had at least three risk factors (Table 3). The burden of the underlying medical conditions ranged from about 8 million persons with cancer to about 72 million persons with hypertension. The region-specific burden of having at least three risk factors ranged from 1.5 million persons in Northern Europe to 9.5 million persons in Eastern Europe (Table 3). The burden of risk factors in the specific age groups can be found in Supplementary Table 7.