Figure 2

Shown is the distribution according to age and sex among all the participants in the study who were targeted for testing for the presence of SARS-CoV-2 (Panel A), among those who participated in the open invitation of the population screening (Panel B), and among those who participated in the random sample (Panel C). Also shown are the percentages of participants who tested positive stratified according to sex in the targeted-testing group (Panel D) and in the population-screening group (Panel E). In addition, the percentage of participants who tested positive in the population screening is shown according to sampling date in the open invitation (black) and the random sampling (red) (Panel F). The solid blue curve in Panel F indicates the logistic-regression line, and the dashed lines indicate the 95% confidence intervals (CI) of the logistic regression. The logistic-regression slope corresponds to a change of −2% (95% CI, −5 to 1) in the infection rate per day. The vertical bars indicate 95% confidence intervals for age groups (in Panels D and E) and for individual dates (in Panel F).