Table 1. Number of contacts by demographic characteristics and location.
N is the number of participants who provided non-missing contact data.
| Characteristics | Wuhan | Shanghai | ||||||||
| Baseline period | COVID-19 outbreak | Difference§ | Baseline period | COVID-19 outbreak | Difference§ | |||||
|
N (%)† |
Mean (95% CI‡) |
N (%)† |
Mean (95% CI‡) |
N (%) |
Mean (95% CI‡) |
N (%) |
Mean (95% CI‡) |
|||
| Overall | 624 (100.0) |
14.6 (12.9, 16.3) |
627 (100.0) |
2 (1.9, 2.1) |
12.6*** | 965 (100.0) |
18.8 (17.8, 19.8) |
557 (100.0) |
2.3 (2, 2.8) |
16.4*** |
| Sex | ||||||||||
| Male | 300 (48.1) |
14.5 (12.2, 17.1) |
301 (48) |
1.8 (1.7, 2) |
12.6*** | 474 (49.1) |
19 (16.9, 21) |
286 (51.3) |
2.1 (1.9, 2.4) |
16.9*** |
| Female | 324 (51.9) |
14.7 (12.5, 17.1) |
326 (52) |
2.1 (2, 2.3) |
12.5*** | 491 (50.9) |
18.5 (16.8, 20.4) |
271 (48.7) |
2.6 (2.1, 3.6) |
16*** |
| Age group | ||||||||||
| 0–6 years | 12 (1.9) |
8.6 (3.4, 17.4) |
12 (1.9) |
2.2 (1.7, 2.8) |
6.4*** | 88 (9.1) |
11.6 (9.2, 14.3) |
14 (2.5) |
1.9 (1.7, 2.2) |
9.7*** |
| 7–19 years | 79 (12.7) |
16.2 (12.7, 19.6) |
79 (12.6) |
2.1 (2, 2.2) |
14.1*** | 141 (14.6) |
27 (23.1, 30.7) |
55 (9.9) |
2.6 (2, 3.4) |
24.5*** |
| 20–39 years | 254 (40.7) |
15.3 (12.8, 18) |
256 (40.8) |
2.1 (1.9, 2.2) |
13.2*** | 236 (24.5) |
22.4 (19.8, 25.9) |
254 (45.6) |
2.2 (2, 2.5) |
20.2*** |
| 40–59 years | 221 (35.4) |
13.8 (11.4, 16.7) |
220 (35.1) |
2 (1.8, 2.2) |
11.8*** | 233 (24.1) |
19.9 (17.7, 23.3) |
160 (28.7) |
2.8 (2, 4.1) |
17.1*** |
| ≥60 years | 58 (9.3) |
13.9 (7.9, 20.7) |
60 (9.6) |
1.4 (1.2, 1.7) |
11.6*** | 267 (27.7) |
12.6 (10.8, 14.7) |
74 (13.3) |
1.6 (1.3, 1.8) |
11*** |
| Type of profession | ||||||||||
| Preschool | 12 (1.9) |
8.6 (3.4, 17.4) |
12 (1.9) |
2.2 (1.7, 2.8) |
6.4*** | 79 (8.2) |
10.4 (8, 13.3) |
14 (2.5) |
1.9 (1.7, 2.1) |
8.5*** |
| Student | 107 (17.1) |
14.6 (11.4, 18.2) |
107 (17.1) |
2.1 (2, 2.3) |
12.5*** | 173 (17.9) |
26.2 (23.1, 29.2) |
71 (12.7) |
2.5 (2, 3.4) |
23.7*** |
| Employed | 391 (62.7) |
15.4 (13.4, 17.4) |
390 (62.2) |
2.1 (1.9, 2.2) |
13.2*** | 400 (41.5) |
22.5 (20.7, 24.4) |
354 (63.6) |
2.5 (2.1, 3.2) |
20*** |
| Working-age not in the labor force | 30 (4.8) |
14.1 (5.7, 24.2) |
31 (4.9) |
1.8 (1.4, 2.4) |
12.2*** | 29 (3) |
14.5 (7.8, 24.2) |
24 (4.3) |
1.8 (1.3, 2.4) |
12.6*** |
| Retired | 84 (13.5) |
12.1 (7.2, 17.4) |
87 (13.9) |
1.5 (1.3, 1.7) |
10.6*** | 278 (28.8) |
11.8 (10.2, 13.2) |
94 (16.9) |
1.6 (1.3, 1.8) |
10.2*** |
| Household size | ||||||||||
| 1 | 45 (7.2) |
10.5 (5.3, 17.2) |
45 (7.2) |
0.6 (0.1, 1.5) |
9.9*** | 35 (3.6) |
15.2 (10.1, 21.1) |
61 (11) |
0.3 (0.1, 0.5) |
14.9*** |
| 2 | 73 (11.7) |
12.6 (8.2, 18.3) |
76 (12.1) |
1.1 (1, 1.2) |
11.5*** | 244 (25.3) |
14.5 (12.7, 16.7) |
138 (24.8) |
1.4 (1.1, 1.7) |
13.1*** |
| 3 | 282 (45.2) |
14.8 (12.8, 17.3) |
283 (45.1) |
1.9 (1.8, 2) |
13*** | 432 (44.8) |
20.3 (17.7, 22.4) |
216 (38.8) |
2.2 (2, 2.3) |
18.1*** |
| 4 | 133 (21.3) |
11.9 (9.3, 15) |
132 (21.1) |
2.3 (2.2, 2.5) |
9.6*** | 117 (12.1) |
20.3 (16.5, 23.8) |
78 (14) |
3 (2.8, 3.3) |
17.3*** |
| ≥5 | 91 (14.6) |
21.5 (16.2, 27.3) |
91 (14.5) |
3.2 (2.9, 3.4) |
17.8*** | 137 (14.2) |
21.4 (18.2, 27) |
64 (11.5) |
5.9 (4, 9.9) |
15.5*** |
†Can differ from total sample size (N = 636) because it also includes participants who had not recorded contacts during the baseline period or during the COVID-19 outbreak. Note that reduced denominators indicate missing data. Percentages may not total 100 because of rounding.
‡The 95% CIs on the mean are calculated by bootstrap sampling.
§Difference is calculated by the subtraction of the number of contacts during the outbreak from the number of contacts during the baseline period. p values are taken from a negative binomial regression with a single binary variable distinguishing the baseline period from the outbreak.
*p < 0.05; **p < 0.01; ***p < 0.001.