Table 1.
Sociodemographic and health-related characteristics of the participants.
| Group 1 |
Group 2 |
Group 3 |
Total |
|
|---|---|---|---|---|
| N (% in column) = 16,481 (55.48%) | N (% in column) = 9603 (32.32%) | N (% in column) = 3624 (12.20%) | N = 29,708 | |
| Sociodemographic characteristics | ||||
| Age (years) | ||||
| Mean (SD) | 55.22 (16.10) | 46.86 (15.47) | 54.49 (16.02) | 52.43 (16.35) |
| Gender (SA) | ||||
| Women | 8740 (53.03) | 4849 (50.49) | 1867 (51.52) | 15,456 (52.03) |
| Men | 7741 (46.97) | 4754 (49.51) | 1757 (48.48) | 14,252 (47.97) |
| Region (SA) | ||||
| Hokkaido and Tohoku | 1948 (11.82) | 1058 (11.02) | 429 (11.84) | 3435 (11.56) |
| Hokkaido | 913 (5.54) | 487 (5.07) | 204 (5.63) | 1604 (5.40) |
| Aomori | 151 (0.92) | 86 (0.90) | 22 (0.61) | 259 (0.87) |
| Iwate | 129 (0.78) | 91 (0.95) | 34 (0.94) | 254 (0.85) |
| Miyagi | 325 (1.97) | 175 (1.82) | 87 (2.40) | 587 (1.98) |
| Akita | 124 (0.75) | 60 (0.62) | 15 (0.41) | 199 (0.67) |
| Yamagata | 119 (0.72) | 63 (0.66) | 25 (0.69) | 207 (0.70) |
| Fukushima | 187 (1.13) | 96 (1.00) | 42 (1.16) | 325 (1.09) |
| Kanto | 5364 (32.55) | 3345 (34.83) | 1308 (36.09) | 10,017 (33.72) |
| Ibaraki | 277 (1.68) | 161 (1.68) | 49 (1.35) | 487 (1.64) |
| Tochigi | 162 (0.98) | 101 (1.05) | 40 (1.10) | 303 (1.02) |
| Gunma | 165 (1.00) | 79 (0.82) | 34 (0.94) | 278 (0.94) |
| Saitama | 868 (5.27) | 507 (5.28) | 189 (5.22) | 1564 (5.26) |
| Chiba | 752 (4.56) | 436 (4.54) | 185 (5.10) | 1373 (4.62) |
| Tokyo | 1829 (11.10) | 1270 (13.23) | 524 (14.46) | 3623 (12.20) |
| Kanagawa | 1311 (7.95) | 791 (8.24) | 287 (7.92) | 2389 (8.04) |
| Chubu | 3109 (18.86) | 1710 (17.81) | 619 (17.08) | 5438 (18.30) |
| Niigata | 349 (2.12) | 173 (1.80) | 67 (1.85) | 589 (1.98) |
| Toyama | 146 (0.89) | 84 (0.87) | 30 (0.83) | 260 (0.88) |
| Ishikawa | 158 (0.96) | 91 (0.95) | 22 (0.61) | 271 (0.91) |
| Fukui | 96 (0.58) | 40 (0.42) | 19 (0.52) | 155 (0.52) |
| Yamanashi | 103 (0.62) | 50 (0.52) | 23 (0.63) | 176 (0.59) |
| Nagano | 291 (1.77) | 149 (1.55) | 66 (1.82) | 506 (1.70) |
| Gifu | 228 (1.38) | 125 (1.30) | 44 (1.21) | 397 (1.34) |
| Shizuoka | 404 (2.45) | 224 (2.33) | 74 (2.04) | 702 (2.36) |
| Aichi | 1092 (6.63) | 653 (6.80) | 236 (6.51) | 1981 (6.67) |
| Mie | 242 (1.47) | 121 (1.26) | 38 (1.05) | 401 (1.35) |
| Kansai | 2601 (15.78) | 1625 (16.92) | 567 (15.65) | 4793 (16.13) |
| Shiga | 126 (0.76) | 89 (0.93) | 34 (0.94) | 249 (0.84) |
| Kyoto | 311 (1.89) | 205 (2.13) | 78 (2.15) | 594 (2.00) |
| Osaka | 1172 (7.11) | 743 (7.74) | 235 (6.48) | 2150 (7.24) |
| Hyogo | 741 (4.50) | 442 (4.60) | 168 (4.64) | 1351 (4.55) |
| Nara | 176 (1.07) | 105 (1.09) | 37 (1.02) | 318 (1.07) |
| Wakayama | 75 (0.46) | 41 (0.43) | 15 (0.41) | 131 (0.44) |
| Chugoku and Shikoku | 1556 (9.44) | 821 (8.55) | 288 (7.95) | 2665 (8.97) |
| Tottori | 65 (0.39) | 43 (0.45) | 12 (0.33) | 120 (0.40) |
| Shimane | 65 (0.39) | 49 (0.51) | 21 (0.58) | 135 (0.45) |
| Okayama | 296 (1.80) | 165 (1.72) | 55 (1.52) | 516 (1.74) |
| Hiroshima | 410 (2.49) | 226 (2.35) | 79 (2.18) | 715 (2.41) |
| Yamaguchi | 162 (0.98) | 75 (0.78) | 25 (0.69) | 262 (0.88) |
| Tokushima | 96 (0.58) | 53 (0.55) | 21 (0.58) | 170 (0.57) |
| Kagawa | 166 (1.01) | 79 (0.82) | 22 (0.61) | 267 (0.90) |
| Ehime | 221 (1.34) | 96 (1.00) | 36 (0.99) | 353 (1.19) |
| Kochi | 75 (0.46) | 35 (0.36) | 17 (0.47) | 127 (0.43) |
| Kyusyu and Okinawa | 1903 (11.55) | 1044 (10.87) | 413 (11.40) | 3360 (11.31) |
| Fukuoka | 867 (5.26) | 517 (5.38) | 207 (5.71) | 1591 (5.36) |
| Saga | 94 (0.57) | 53 (0.55) | 23 (0.63) | 170 (0.57) |
| Nagasaki | 188 (1.14) | 71 (0.74) | 30 (0.83) | 289 (0.97) |
| Kumamoto | 221 (1.34) | 105 (1.09) | 46 (1.27) | 372 (1.25) |
| Oita | 117 (0.71) | 79 (0.82) | 26 (0.72) | 222 (0.75) |
| Miyazaki | 128 (0.78) | 45 (0.47) | 25 (0.69) | 198 (0.67) |
| Kagoshima | 162 (0.98) | 93 (0.97) | 28 (0.77) | 283 (0.95) |
| Okinawa | 126 (0.76) | 81 (0.84) | 28 (0.77) | 235 (0.79) |
| Highest educational level (SA) | ||||
| Middle school | 475 (2.88) | 216 (2.25) | 130 (3.59) | 821 (2.76) |
| High school | 5828 (35.36) | 2908 (30.28) | 1327 (36.62) | 10,063 (33.87) |
| Junior college | 3193 (19.37) | 1906 (19.85) | 685 (18.90) | 5784 (19.47) |
| University | 6327 (38.39) | 4102 (42.72) | 1326 (36.59) | 11,755 (39.57) |
| Graduate school (master's course) | 532 (3.23) | 381 (3.97) | 107 (2.95) | 1020 (3.43) |
| Graduate school (doctoral course) | 126 (0.76) | 90 (0.94) | 49 (1.35) | 265 (0.89) |
| Occupation type (SA) | ||||
| Agriculture, forestry and fisheries | 117 (0.71) | 51 (0.53) | 31 (0.86) | 199 (0.67) |
| Construction | 414 (2.51) | 339 (3.53) | 112 (3.09) | 865 (2.91) |
| Manufacturing | 1436 (8.71) | 1224 (12.75) | 365 (10.07) | 3025 (10.18) |
| Information and communications | 472 (2.86) | 332 (3.46) | 92 (2.54) | 896 (3.02) |
| Transportation and postal services | 388 (2.35) | 329 (3.43) | 92 (2.54) | 809 (2.72) |
| Wholesale and retail trade | 1026 (6.23) | 723 (7.53) | 218 (6.02) | 1967 (6.62) |
| Finance and insurance | 328 (1.99) | 272 (2.83) | 79 (2.18) | 679 (2.29) |
| Real estate and goods rental and leasing | 203 (1.23) | 152 (1.58) | 78 (2.15) | 433 (1.46) |
| Scientific research, professional and technical services | 212 (1.29) | 147 (1.53) | 46 (1.27) | 405 (1.36) |
| Accommodations, food and beverage services | 341 (2.07) | 244 (2.54) | 67 (1.85) | 652 (2.19) |
| Living-related and personal services and amusement services | 237 (1.44) | 183 (1.91) | 57 (1.57) | 477 (1.61) |
| Education and learning support | 527 (3.20) | 409 (4.26) | 95 (2.62) | 1031 (3.47) |
| Medical healthcare and welfare | 889 (5.39) | 761 (7.92) | 216 (5.96) | 1866 (6.28) |
| Combined services | 105 (0.64) | 95 (0.99) | 34 (0.94) | 234 (0.79) |
| Services (not elsewhere classified) | 1306 (7.92) | 909 (9.47) | 313 (8.64) | 2528 (8.51) |
| Public service (not elsewhere classified) | 474 (2.88) | 349 (3.63) | 99 (2.73) | 922 (3.10) |
| Students | 278 (1.69) | 298 (3.10) | 43 (1.19) | 619 (2.08) |
| Homemaker | 4204 (25.51) | 1592 (16.58) | 877 (24.20) | 6673 (22.46) |
| Others | 3524 (21.38) | 1194 (12.43) | 710 (19.59) | 5428 (18.27) |
| Annual household income in 2020 (million JPY; thousand USD) (SA) | ||||
| –1); −9.2) | 1117 (6.78) | 590 (6.14) | 332 (9.16) | 2039 (6.86) |
| [1–2); [9.2–18.4) | 1566 (9.50) | 721 (7.51) | 402 (11.09) | 2689 (9.05) |
| [2–3); [18.4–27.6) | 2395 (14.53) | 1186 (12.35) | 541 (14.93) | 4122 (13.88) |
| [3–4); [27.6–36.8) | 2687 (16.30) | 1346 (14.02) | 570 (15.73) | 4603 (15.49) |
| [4–5); [36.8–46.0) | 2024 (12.28) | 1320 (13.75) | 480 (13.25) | 3824 (12.87) |
| [5–6); [46–55.2) | 1638 (9.94) | 1039 (10.82) | 321 (8.86) | 2998 (10.09) |
| [6–7); [55.2–64.4) | 1189 (7.21) | 808 (8.41) | 245 (6.76) | 2242 (7.55) |
| [7–8); [64.4–73.6) | 1056 (6.41) | 714 (7.44) | 190 (5.24) | 1960 (6.60) |
| [8–9); [73.6–82.8) | 701 (4.25) | 476 (4.96) | 128 (3.53) | 1305 (4.39) |
| [9–10); [82.8–92.0) | 2108 (12.79) | 1403 (14.61) | 415 (11.45) | 3926 (13.22) |
| Household size including respondent (SA) | ||||
| 1 | 2997 (18.18) | 1835 (19.11) | 691 (19.07) | 5523 (18.59) |
| 2 | 6731 (40.84) | 2922 (30.43) | 1414 (39.02) | 11,067 (37.25) |
| 3 | 3735 (22.66) | 2396 (24.95) | 815 (22.49) | 6946 (23.38) |
| 4 | 2109 (12.80) | 1733 (18.05) | 462 (12.75) | 4304 (14.49) |
| 5 | 619 (3.76) | 503 (5.24) | 164 (4.53) | 1286 (4.33) |
| More than 6 | 290 (1.76) | 214 (2.23) | 78 (2.15) | 582 (1.96) |
| Marital size (SA) | ||||
| Married (including de facto marriage) | 10,237 (62.11) | 5484 (57.11) | 2212 (61.04) | 17,933 (60.36) |
| Not married (without partner) | 3546 (21.52) | 2669 (27.79) | 788 (21.74) | 7003 (23.57) |
| Not married (with a partner) | 753 (4.57) | 738 (7.69) | 196 (5.41) | 1687 (5.68) |
| Widowed | 784 (4.76) | 214 (2.23) | 166 (4.58) | 1164 (3.92) |
| Divorced | 1161 (7.04) | 498 (5.19) | 262 (7.23) | 1921 (6.47) |
| To what extent did the COVID-19 pandemic affect your life, within the past year? (SA) | ||||
| Not at all | 1281 (7.77) | 439 (4.57) | 132 (3.64) | 1852 (6.23) |
| Not much | 4710 (28.58) | 2481 (25.84) | 661 (18.24) | 7852 (26.43) |
| Somewhat | 8246 (50.03) | 5082 (52.92) | 1900 (52.43) | 15,228 (51.26) |
| Quite a lot | 2244 (13.62) | 1601 (16.67) | 931 (25.69) | 4776 (16.08) |
| Health-related characteristics, including health literacy | ||||
| Self-reported health status (SA) | ||||
| Very good | 5101 (30.95) | 2880 (29.99) | 600 (16.56) | 8581 (28.88) |
| Good | 4986 (30.25) | 3143 (32.73) | 913 (25.19) | 9042 (30.44) |
| Fair | 4637 (28.14) | 2633 (27.42) | 1170 (32.28) | 8440 (28.41) |
| Poor | 1449 (8.79) | 824 (8.58) | 723 (19.95) | 2996 (10.08) |
| Very poor | 308 (1.87) | 123 (1.28) | 218 (6.02) | 649 (2.18) |
| Have you ever received a COVID-19 test? (MA) | ||||
| No | 15,322 (92.97) | 8693 (90.52) | 3223 (88.93) | 27,238 (91.69) |
| Yes – PCR test | 789 (4.79) | 613 (6.38) | 233 (6.43) | 1635 (5.50) |
| Yes – antigen test | 119 (0.72) | 139 (1.45) | 79 (2.18) | 337 (1.13) |
| Yes – antibody testing | 140 (0.85) | 107 (1.11) | 52 (1.43) | 299 (1.01) |
| Yes – unsure about either of the three | 183 (1.11) | 126 (1.31) | 76 (2.10) | 385 (1.30) |
| Presence of underlying diseases (e.g. diabetes, heart failure, respiratory disease, COPD, etc., or on dialysis, or using immunosuppressive or anticancer drugs) (SA) | 2238 (13.58) | 708 (7.37) | 992 (27.37) | 3938 (13.26) |
| Living with family members who are elderly or have underlying diseases (SA) | 2778 (16.86) | 1277 (13.30) | 787 (21.72) | 4842 (16.30) |
| Do you receive an influenza vaccine? (SA) | ||||
| Every year | 5873 (35.63) | 3575 (37.23) | 1559 (43.02) | 11,007 (37.05) |
| Every few years | 2807 (17.03) | 1952 (20.33) | 684 (18.87) | 5443 (18.32) |
| Rarely or never | 7801 (47.33) | 4076 (42.45) | 1381 (38.11) | 13,258 (44.63) |
| Did you receive on routine immunization? (SA) | ||||
| All | 3313 (20.10) | 2126 (22.14) | 818 (22.57) | 6257 (21.06) |
| Partially | 2857 (17.34) | 1748 (18.20) | 754 (20.81) | 5359 (18.04) |
| None | 7051 (42.78) | 3800 (39.57) | 1379 (38.05) | 12,230 (41.17) |
| Not sure | 3260 (19.78) | 1929 (20.09) | 673 (18.57) | 5862 (19.73) |
| Has anyone close to you ever been infected with COVID-19? (MA) | ||||
| Family or friends | 431 (2.62) | 360 (3.75) | 139 (3.84) | 930 (3.13) |
| Colleagues at work | 537 (3.26) | 720 (7.50) | 197 (5.44) | 1454 (4.89) |
| No/I don't know. | 15,539 (94.28) | 8567 (89.21) | 3300 (91.06) | 27,406 (92.25) |
| How confident are you filling out medical forms by yourself?” (health literacy) (SA) | ||||
| Not at all | 187 (1.13) | 140 (1.46) | 94 (2.59) | 421 (1.42) |
| A little bit | 554 (3.36) | 508 (5.29) | 307 (8.47) | 1369 (4.61) |
| Somewhat | 3404 (20.65) | 2325 (24.21) | 1051 (29.00) | 6780 (22.82) |
| Extremely | 7385 (44.81) | 4202 (43.76) | 1401 (38.66) | 12,988 (43.72) |
| Quite a bit | 4951 (30.04) | 2428 (25.28) | 771 (21.27) | 8150 (27.43) |
SD: Standard deviation, SA: Single answer, MA: Multiple answer.