Table 2. Baseline characteristics of participants in the Corona Behavioral Unit cohort study, April 2020 –September 2022.
| Characteristics | Total | Round 1 enrolment (N = 89,943) | Round 3 and latera enrolment (N = 99,676) | P-valueb | Retained in the study (N = 65,996) | Lost to follow upc (N = 123,623) | P-value | Subscribed for follow-up (N = 114,021) | Not subscribed (N = 74,786) | P-value |
|---|---|---|---|---|---|---|---|---|---|---|
| Sex | <0.001 | <0.001 | <0.001 | |||||||
| Male | 63739 (34%) | 34096 (53%) | 29643 (47%) | 23654 (37%) | 40085 (63%) | 39701 (62%) | 23844 (38%) | |||
| Female | 125447 (66%) | 55748 (44%) | 69699 (56%) | 43659 (35%) | 81788 (65%) | 74150 (59%) | 50683 (41%) | |||
| Age | <0.001 | <0.001 | <0.001 | |||||||
| 70+ years | 25078 (13%) | 15143 (60%) | 9935 (40%) | 10847 (43%) | 14231 (57%) | 16988 (68%) | 7947 (32%) | |||
| 55-69y | 52567 (28%) | 27448 (52%) | 25119 (48%) | 23495 (45%) | 29072 (55%) | 34579 (66%) | 17730 (34%) | |||
| 40-54y | 55282 (29%) | 27399 (50%) | 27883 (50%) | 19531 (35%) | 35751 (65%) | 33574 (61%) | 21457 (39%) | |||
| 25-39y | 46161 (24%) | 17228 (37%) | 28933 (63%) | 11892 (26%) | 34269 (74%) | 24485 (53%) | 21548 (47%) | |||
| 16-24y | 10531 (6%) | 2725 (26%) | 7806 (74%) | 1627 (15%) | 8904 (85%) | 4395 (42%) | 6104 (58%) | |||
| Educational level d | <0.001 | <0.001 | <0.001 | |||||||
| Lower | 24379 (13%) | 12085 (50%) | 12294 (50%) | 7269 (30%) | 17110 (71%) | 13541 (56%) | 10642 (44%) | |||
| Middle | 57565 (31%) | 25621 (45%) | 31944 (55%) | 18313 (32%) | 39252 (68%) | 32941 (57%) | 42842 (43%) | |||
| Higher | 105413 (56%) | 51283 (49%) | 54130 (51%) | 41031 (39%) | 64382 (61%) | 66217 (63%) | 72842 (37%) | |||
| Living alone | <0.001 | <0.001 | 0.039 | |||||||
| Yes | 29688 (16%) | 75581 (47%) | 84350 (53%) | 56083 (35%) | 103848 (65%) | 96016 (60%) | 63240 (40%) | |||
| No | 159931 (84%) | 14362 (48%) | 15326 (52%) | 11309 (38%) | 18379 (62%) | 18005 (61%) | 11546 (39%) | |||
| Underlying medical condition e | 0.681 | <0.001 | <0.001 | |||||||
| Yes | 142080 (75%) | 67373 (47%) | 74707 (53%) | 48620 (34%) | 93460 (66%) | 34475 (33%) | 102571 (79%) | |||
| No | 47233 (25%) | 22346 (47%) | 24887 (53%) | 18680 (40%) | 28553 (60%) | 2450 (4%) | 32730 (76%) | |||
Note that totals might not add up due to missing values.
a Additional participants that were recruited every other data collection round since round 3.
b Pearson chi square test.
c Not participated for at least four rounds.
d Lower education level represents elementary school or less; Middle education level represents secondary education (academic, vocational, and technical education); Higher education level represents postsecondary education (college, university, professional, vocational, and technical).
e Physical medical condition that could increase the likelihood of severe COVID-19 when infected.