Table 2.
Model estimated change of search index by HDI categories.
| Regions with Low HDI | Regions with Middle HDI | Regions with High HDI | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| RR (95% CI) | p-value | Ratio of RR | RR (95% CI) | p-value | Ratio of RR* | p-value | RR (95% CI) | p-value | Ratio of RR* | p-value | |
| Pre-Covid-19 | |||||||||||
| Yearly change Jan 1 2016–Dec 30 2019 | 1.10 (1.07, 1.13) | < 0.0001 | Reference | 1.11 (1.08, 1.14) | < 0.0001 | 1.01 (0.97, 1.05) | 0.6188 | 1.13 (1.10, 1.16) | < 0.0001 | 1.03 (0.98, 1.07) | 0.2239 |
| Initial COVID-19 wave | |||||||||||
| Level change on Dec 31 2019 | 1.41 (1.34, 1.49) | < 0.0001 | Reference | 1.62 (1.54, 1.70) | < 0.0001 | 1.15 (1.07, 1.23) | 0.0002 | 1.58 (1.48, 1.68) | < 0.0001 | 1.12 (1.03, 1.21) | 0.0091 |
| Level change Jan 18 (HHT announced)–Jan 25 2020 (lockdown) | 106.80 (100.07, 113.99) | < 0.0001 | Reference | 124.55 (117.61, 131.90) | < 0.0001 | 1.16 (1.07, 1.27) | 0.0004 | 125.31 (116.53, 134.75) | < 0.0001 | 1.17 (1.06, 1.30) | 0.0012 |
| Weekly change Jan 25—Jun 10 2020 | 0.90 (0.89, 0.90) | < 0.0001 | Reference | 0.89 (0.88, 0.89) | < 0.0001 | 0.99 (0.98, 0.99) | < 0.0001 | 0.89 (0.89, 0.90) | < 0.0001 | 0.99 (0.99, 1.00) | 0.0768 |
| Beijing outbreak | |||||||||||
| Level change Jun 11- Jun 17 2020 | 1.91 (1.79, 2.03) | < 0.0001 | Reference | 1.34 (1.26, 1.42) | < 0.0001 | 1.01 (0.94, 1.10) | 0.7419 | 2.12 (1.98, 2.27) | < 0.0001 | 1.11 (1.01, 1.21) | 0.0227b |
| Weekly change Jun 17—Oct 11 2020 | 0.96 (0.95, 0.96) | < 0.0001 | Reference | 1.02 (1.01, 1.02) | < 0.0001 | 0.99 (0.98, 1.00) | 0.0059 | 0.94 (0.93, 0.94) | < 0.0001 | 0.98 (0.97, 0.99) | < 0.0001 |
| Qingdao outbreak | |||||||||||
| Level change on Oct 12th | 1.31 (1.23, 1.40) | < 0.0001 | Reference | 1.34 (1.26, 1.42) | < 0.0001 | 1.02 (0.93, 1.11) | 0.6979 | 1.41 (1.31, 1.52) | < 0.0001 | 1.07 (0.97, 1.18) | 0.1693 |
| Weekly change in winter wave Oct 12 2020–Jan 3 2021 | 1.01 (1.00, 1.01) | 0.0647 | Reference | 1.02 (1.01, 1.02) | < 0.0001 | 1.01 (0.99, 1.02) | 0.1043 | 1.02 (1.01, 1.03) | 0.0002 | 1.01 (0.99, 1.02) | 0.1058 |
| Shijiazhuang outbreak | |||||||||||
| Level change Jan 3–Jan 7 2021 | 2.00 (1.85, 2.16) | < 0.0001 | Reference | 2.67 (2.50, 2.86) | < 0.0001 | 1.34 (1.21, 1.48) | < 0.0001 | 2..45 (2.24, 2.67) | < 0.0001 | 1.22 (1.09, 1.37) | 0.0007 |
| Weekly change Jan 7–Mar 15 2021 | 0.83 (0.82, 0.84) | < 0.0001 | Reference | 0.80 (0.79, 0.80) | < 0.0001 | 0.95 (0.94, 0.97) | < 0.0001 | 0.78 (0.77, 0.79) | < 0.0001 | 0.94 (0.93, 0.96) | < 0.0001 |
*In reference to the low HDI category.
bNot significant, after applying Holm-Bonferroni adjustment to maintain a family-wide type I error rate of 0.05 (All p values for the tests that are not marked “b” are significant unless they are greater tan 0.05).