Table 1 Characteristics of participants.
All participants (n = 30,130) | Participants infected with SARS-CoV-2 (n = 1117) | |
|---|---|---|
Age, n (%)* | ||
≤ 34 years | 8450 (28.0) | 657 (58.8) |
35–49 years | 7696 (25.5) | 289 (25.9) |
50–64 years | 6661 (22.1) | 108 (9.7) |
≥ 65 years | 7323 (24.3) | 62 (5.6) |
Sex, n (%) | ||
Male | 14,718 (48.8) | 714 (63.9) |
Female | 15,412 (51.2) | 403 (36.1) |
Tobacco use status, n (%) | ||
Never-user | 16,210 (53.8) | 380 (34.0) |
Former user (combustible cigarettes or HTPs) | 6584 (21.9) | 145 (13.0) |
Current user of combustible cigarettes | 3571 (11.9) | 92 (8.2) |
Current user of HTPs | 1558 (5.2) | 75 (6.7) |
Current dual user (combustible cigarettes and HTPs) | 2206 (7.3) | 425 (38.0) |
Occupation, n (%) | ||
Student/unemployed/retiree | 10,283 (34.1) | 157 (14.1) |
Healthcare worker | 2265 (7.5) | 94 (8.4) |
Remote worker | 1521 (5.0) | 85 (7.6) |
Other worker | 16,061 (53.3) | 781 (69.9) |
Household annual income, n (%) | ||
Below average | 14,651 (48.6) | 545 (48.8) |
Above average (higher) | 8392 (27.9) | 374 (33.5) |
Did not know/did not want to answer | 7087 (23.5) | 198 (17.7) |
Education, n (%) | ||
Junior high school/high school | 15,614 (51.8) | 555 (49.7) |
University/technical school or more | 14,516 (48.2) | 561 (50.2) |
Housing tenure, n (%) | ||
Own house | 22,665 (75.2) | 728 (65.2) |
Rental house | 6903 (22.9) | 359 (32.1) |
Other (freeloader/rootless) | 562 (1.9) | 30 (2.7) |
Living in prefectures under alert, n (%)† | ||
No | 11,997 (39.8) | 315 (28.2) |
Yes | 18,133 (60.2) | 802 (71.8) |
Household members other than the participant, n (%) | ||
None (living alone) | 5091 (16.9) | 249 (22.3) |
Adult(s) only | 16,641 (55.2) | 425 (38.0) |
Living with a child (children)‡ | 8398 (27.9) | 443 (39.7) |
Interacting with people living separately at least once a week, n (%) | ||
No | 19,453 (64.6) | 491 (44.0) |
Yes | 10,677 (35.4) | 625 (56.0) |
Total METs per day, n (%) | ||
Below average | 22,489 (74.6) | 607 (54.3) |
Above average (more active) | 7641 (25.4) | 510 (45.7) |
Alcohol consumption, n (%) | ||
Never drinker | 13,096 (43.5) | 394 (35.3) |
Ever drinker | 17,034 (56.5) | 723 (64.7) |
Comorbidities, n (%) | ||
None | 18,746 (62.2) | 671 (60.1) |
One comorbidity | 6558 (21.8) | 154 (13.8) |
Two or more comorbidities | 4826 (16.0) | 292 (26.1) |
Obesity (BMI ≥ 30 kg/m2) | 1127 (3.7) | 42 (3.8) |
Diabetes | 2170 (7.2) | 161 (14.4) |
Hypertension | 7116 (23.6) | 298 (26.7) |
Hyperlipidemia | 4346 (14.4) | 198 (17.7) |
Cardiovascular disease | 809 (2.7) | 135 (12.1) |
Cerebrovascular disease | 466 (1.5) | 145 (13.0) |
Chronic kidney disease | 509 (1.7) | 138 (12.4) |
Chronic hepatitis or cirrhosis | 425 (1.4) | 148 (13.2) |
Chronic obstructive pulmonary disease | 369 (1.2) | 146 (13.1) |
Asthma | 1175 (3.9) | 181 (16.2) |
Malignant tumor | 717 (2.4) | 152 (13.6) |
Immunodeficiency§ | 678 (2.3) | 140 (12.5) |
Engagement in infection prevention measures, n (%)¶ | ||
Below average | 11,476 (38.1) | 671 (60.1) |
Above average (more careful) | 18,654 (61.9) | 446 (39.9) |
SARS-CoV-2 vaccination status, n (%) | ||
No or one time of mRNA vaccination | 4329 (14.4) | 239 (21.4) |
Two or three times of vaccination | 25,801 (85.6) | 878 (78.6) |
Year of infection, n (%) | ||
Over one year prior to the survey | – | 591 (52.9) |
Within the preceding year | – | 546 (48.9) |
Hospitalization due to COVID-19, n (%) | ||
No | – | 616 (55.1) |
Yes | – | 501 (44.9) |
Oxygen administration due to COVID-19, n (%) | ||
No | – | 641 (57.4) |
Yes | – | 476 (42.6) |
