Table 1 Participant characteristics stratified by data collection period
|  | Period 1 29 May 2020 to 3 Jul 2020 n = 115 (%) | Period 2 28 Aug 2020 to 25 Sep 2020 n = 158 (%) | Period 3 1 Dec 2020 to 15 Jan 2021 n = 174 (%) | Period 4 1 Mar 2021 to 23 Mar 2021 n = 168 (%) | Total N = 615 (%) | p value |
|---|---|---|---|---|---|---|
Sex | ||||||
 Female | 62 (53.9) | 100 (63.3) | 99 (56.9) | 81 (48.2) | 342 (55.6) | 0.052 |
 Male | 53 (46.1) | 58 (36.7) | 75 (43.1) | 87 (51.8) | 273 (44.4) | |
Age | ||||||
 Mean (SD) | 35.2 (15.2) | 36.4 (14.0) | 36.6 (14.3) | 33.9 (13.8) | 35.5 (14.3) | 0.292 |
 Median [IQR] | 32.0 [23.2, 43.2] | 34.0 [24.1, 47.5] | 35.9 [26.5, 45.6] | 32.8 [22.5, 42.4] | 33.5 [24.0, 45.3] | |
Age groups | ||||||
 Below 18 | 10 (8.7) | 10 (6.3) | 14 (8.0) | 23 (13.7) | 57 (9.3) | 0.366 |
 18–39 | 63 (54.8) | 86 (54.4) | 95 (54.6) | 91 (54.2) | 335 (54.5) | |
 40–49 | 23 (20.0) | 35 (22.2) | 29 (16.7) | 27 (16.1) | 114 (18.5) | |
 50–59 | 12 (10.4) | 17 (10.8) | 29 (16.7) | 22 (13.1) | 80 (13.0) | |
 60 and above | 7 (6.1) | 10 (6.3) | 7 (4.0) | 5 (3.0) | 29 (4.7) | |
Educationa | ||||||
 None | 2 (1.7) | 0 | 0 | 0 | 2 (0.3) | 0.001 |
 Primary | 11 (9.6) | 7 (4.5) | 15 (8.7) | 12 (7.3) | 45 (7.4) | |
 Secondary | 28 (24.3) | 48 (30.6) | 37 (21.4) | 24 (20.6) | 147 (24.1) | |
 Vocational | 5 (4.3) | 16 (10.2) | 6 (3.5) | 26 (15.8) | 53 (8.6) | |
 Tertiary | 68 (59.1) | 86 (54.8) | 114 (65.9) | 91 (55.2) | 359 (58.9) | |
 Post-graduate | 1 (0.9) | 0 | 1 (0.6) | 2 (1.2) | 4 (0.7) | |
Occupationa | ||||||
 Call center agent | 4 (3.5) | 7 (4.4) | 2 (1.1) | 1 (0.6) | 14 (2.3) | 0.001 |
 Cleaning services | 1 (0.9) | 12 (7.6) | 1 (0.6) | 20 (12.4) | 34 (5.6) | |
 Delivery services | 0 | 1 (0.6) | 3 (1.7) | 2 (1.2) | 6 (1.0) | |
 Driver | 1 (0.9) | 6 (3.8) | 8 (4.6) | 6 (3.7) | 21 (3.5) | |
 Factory worker | 1 (0.9) | 1 (0.6) | 0 | 0 | 2 (0.3) | |
 Food services | 4 (3.5) | 7 (4.4) | 1 (0.6) | 2 (1.2) | 14 (2.3) | |
 Grocery staff | 10 (8.8) | 2 (1.3) | 4 (2.3) | 3 (1.9) | 19 (3.1) | |
 Healthcare worker | 0 | 3 (1.9) | 2 (1.1) | 4 (2.5) | 9 (1.5) | |
 House helper | 2 (1.8) | 1 (0.6) | 3 (1.7) | 0 | 6 (1.0) | |
 Laborer | 8 (7.0) | 8 (5.1) | 16 (9.2) | 10 (6.2) | 42 (6.9) | |
 Office worker | 12 (10.5) | 13 (8.2) | 19 (10.9) | 12 (7.5) | 56 (9.2) | |
 Overseas Filipino worker | 0 | 1 (0.6) | 1 (0.6) | 0 | 2 (0.3) | |
 Others | 18 (15.8) | 19 (12.0) | 23 (13.2) | 21 (13.0) | 81 (13.3) | |
 Security personnel | 2 (1.8) | 0 | 5 (2.9) | 3 (1.9) | 10 (1.6) | |
 Vendor | 3 (2.6) | 7 (4.4) | 8 (4.6) | 6 (3.6) | 24 (4.0) | |
 Wellness or grooming | 1 (0.9) | 0 | 0 | 1 (0.6) | 2 (0.3) | |
 Unemployed | 47 (41.2) | 70 (44.3) | 78 (44.8) | 70 (43.5) | 265 (43.7) | |
Frontline essential workera,b | ||||||
 Yes | 31 (32.0) | 53 (34.0) | 54 (31.2) | 67 (41.1) | 205 (34.8) | 0.238 |
 No | 66 (68.0) | 103 (66.0) | 119 (68.8) | 96 (58.9) | 384 (65.2) | |
Monthly household income (PHP)a | ||||||
 ≤ 20,000 | 82 (77.4) | 106 (82.2) | 106 (86.2) | 101 (89.4) | 395 (83.9) | 0.085 |
 > 20,000 | 24 (22.6) | 23 (17.8) | 17 (13.8) | 12 (10.6) | 76 (16.1) | |
Any medical comorbiditya,c | ||||||
 Yes | 28 (24.3) | 31 (19.6) | 31 (18.0) | 30 (18.0) | 120 (19.6) | 0.532 |
 No | 87 (75.7) | 127 (80.4) | 141 (82.0) | 137 (82.0) | 492 (80.4) | |
Regular smokingd | ||||||
 Yes | 11 (9.6) | 15 (9.5) | 19 (10.9) | 18 (10.7) | 63 (10.2) | 0.964 |
 No | 104 (90.4) | 143 (90.5) | 155 (89.1) | 150 (89.3) | 552 (89.8) | |
Regular alcoholic beverage drinkinge | ||||||
 Yes | 2 (1.7) | 6 (3.8) | 12 (6.9) | 10 (6.0) | 30 (4.9) | 0.188 |
 No | 113 (98.3) | 152 (96.2) | 162 (93.1) | 158 (94.0) | 585 (95.1) | |
Any symptom during enrollmentf | ||||||
 Yes | 50 (43.9) | 32 (20.4) | 11 (6.4) | 18 (10.9) | 111 (18.3) |  < 0.001 |
 No | 64 (56.1) | 125 (79.6) | 161 (93.6) | 147 (89.1) | 497 (81.7) | |
Household sizea | ||||||
 ≤ 4 persons | 33 (29.5) | 74 (46.8) | 80 (46.2) | 86 (51.5) | 273 (44.8) | 0.003 |
 > 4 persons | 79 (70.5) | 84 (53.2) | 93 (53.8) | 81 (48.5) | 337 (55.2) | |
Recent exposure to any person with respiratory symptomsa | ||||||
 Yes | 22 (19.3) | 16 (10.3) | 6 (3.4) | 1 (0.6) | 45 (7.4) |  < 0.001 |
 No | 92 (80.7) | 140 (88.6) | 168 (96.6) | 165 (99.4) | 565 (92.6) | |
Recent exposure to any person with suspected or confirmed COVID-19a | ||||||
 Yes | 5 (4.5) | 4 (2.5) | 6 (3.5) | 0 | 15 (2.5) | 0.081 |
 No | 107 (95.5) | 153 (97.5) | 167 (96.5) | 165 (100) | 592 (97.5) | |
Living with person with COVID-19 signs and symptomsf | ||||||
 Yes | 20 (17.4) | 8 (5.1) | 3 (1.7) | 0 | 31 (5.1) |  < 0.001 |
 No | 95 (82.6) | 149 (94.9) | 171 (98.3) | 166 (100) | 581 (94.9) | |
Regular mask wearinga | ||||||
 At home and in public | 6 (5.2) | 8 (5.1) | 7 (4.0) | 0 | 21 (3.4) | 0.059 |
 In public | 108 (93.9) | 149 (94.9) | 166 (96.0) | 165 (98.8) | 588 (96.1) | |
 No | 1 (0.9) | 0 | 0 | 2 (1.2) | 3 (0.5) | |
Social distancing at homea | ||||||
 Yes | 37 (32.5) | 80 (50.6) | 55 (32.0) | 73 (43.7) | 245 (39.8) | 0.001 |
 No | 77 (67.5) | 78 (49.4) | 117 (68.0) | 94 (56.3) | 366 (59.5) | |
Handwashing upon return from outdoorsa | ||||||
 Always | 104 (90.4) | 157 (99.4) | 167 (96.0) | 162 (97.6) | 590 (96.2) | 0.005 |
 Sometimes | 9 (7.8) | 0 | 6 (3.4) | 2 (1.2) | 17 (2.8) | |
 Rarely | 2 (1.7) | 1 (0.6) | 1 (0.6) | 2 (1.2) | 6 (1.0) | |
Handwashing upon food consumption | ||||||
 Always | 108 (93.9) | 157 (99.4) | 167 (96.0) | 163 (97.0) | 595 (96.7) | 0.115 |
 Sometimes | 4 (3.5) | 0 | 6 (3.4) | 2 (1.2) | 12 (2.0) | |
 Rarely | 3 (2.6) | 1 (0.6) | 1 (0.6) | 3 (1.8) | 8 (1.3) | |
Handwashing with toilet use | ||||||
 Always | 111 (96.5) | 157 (99.4) | 168 (96.6) | 161 (95.8) | 597 (97.1) | 0.232 |
 Sometimes | 4 (3.5) | 0 | 5 (2.9) | 4 (2.4) | 13 (2.1) | |
 Rarely | 0 | 1 (0.6) | 1 (0.6) | 3 (1.8) | 5 (0.8) | |