Table 3.

Contact history and frequency of outdoor activities among participants 14 days before returning to Macao

	Total (N = 1137)	Non-infected (N = 1113)	Infected (N = 24)	P value
Contact history
Went to any hospitals or clinics for any reason (Yes, %)	56/1137 (4.93%)	53/1113 (4.76%)	3/24 (12.5%)	0.110
Went to hospitals or clinics for respiratory symptoms (Yes, %)	20/1137 (1.76%)	18/1113 (1.62%)	2/24 (8.33%)	0.064
Had physical contact with anyone who had respiratory symptoms (Yes, %)	91/1137 (8%)	85/1113 (7.64%)	6/24 (25%)	0.002
If yes, did you wear a mask during your contact (Yes, %)	58/91 (63.74%)	57/85 (67.06%)	1/6 (16.67%)	0.022
If yes, did you wash your hands after your contact (Yes, %)	84/91 (92.31%)	81/85 (95.29%)	3/6 (50%)	0.005
Had physical contact with suspected/confirmed COVID-19 patients (including family members) (Yes, %)	25/1137 (2.2%)	21/1113 (1.89%)	4/24 (16.67%)	0.001
If yes, did you wear a mask during the contact (Yes, %)	13/25 (52%)	13/21 (61.9%)	0/4 (0%)	0.039
If yes, did you wash your hands after your contact (Yes, %)	25/1137 (2.2%)	20/21 (95.24%)	2/4 (50%)	0.057
Frequency of outdoor activities (Total number measured in a 14-day interval before returning to Macau)
Went to workplace (mean ± std. deviation)	0.73 ± 2.41	0.7 ± 2.4	0.8 ± 2.6	0.833
Went to school (mean ± std. deviation)	2.32 ± 3.7	2.3 ± 3.7	3.4 ± 5.1	0.291
Went to crowded places, such as supermarkets, malls, and cinemas (mean ± std. deviation)	2.34 ± 2.43	2.3 ± 2.4	3.8 ± 4.6	0.142
Took public transportation vehicles, such as bus, underground transit, train, and aircraft but excluding taxi (mean ± std. deviation)	2.52 ± 4.36	2.5 ± 4.3	4.5 ± 5.7	0.110
Participated in high-risk gathering activities defined by interacting with people within 2 m without wearing a mask such as parties, bars, restaurants, family and friend gatherings (mean ± std. deviation)	0.82 ± 2.77	0.7 ± 2.3	5.4 ± 10.1	0.034