Correlation analysis between Baidu Index data and outpatient data
We conducted a correlation analysis between Baidu index search volume and outpatient visits and obtained their R values each year. From 2017 to 2021, their R values were 0.875, 0.781, 0.851, 0.243, and 0.782 respectively (P=0.079 in 2020, P < 0.01 in other years). It can be seen that in 2020, the year of the COVID-19 pandemic, the correlation was poor, as shown in Figure 4, and good for the rest of the years.
The author further divided the data for 2020 into the first half and the second half and conducted a comparative analysis again. It was found that there was a significant correlation between Baidu search volume and outpatient visits from January to June in 2020 (R-value was 0.885, P < 0.01), while there was no significant correlation between them from July to December in 2020 (R-value was 0.017, P=0.928). In the second half of 2020, the number of outpatient visits gradually increased, while Baidu search volume showed no obvious trend of increase.