Table 1.
Characteristics of study participants (desk workers aged 18–59 years).
| Total 1 | LBP− 2 | LBP+ 2 | p Value | ||
|---|---|---|---|---|---|
| (n = 4227) | (n = 4055 [95.9%]) | (n = 172 [4.1%]) | |||
| Working from home has increased | Yes | 1323 (31.3) | 1240 (93.7) | 83 (6.3) | <0.001 |
| No | 2904 (68.7) | 2815 (96.9) | 89 (3.1) | ||
| Age (years) | 18–29 | 742 (17.5) | 713 (96.1) | 29 (3.9) | 0.221 |
| 30–44 | 1681 (39.8) | 1602 (95.3) | 79 (4.7) | ||
| 45–59 | 1804 (42.7) | 1740 (96.5) | 64 (3.5) | ||
| Sex | Female | 1668 (39.5) | 1602 (96.0) | 66 (4.0) | 0.766 |
| Male | 2559 (60.5) | 2453 (95.9) | 106 (4.1) | ||
| Overweight or obese 3 | Yes | 779 (18.4) | 745 (95.6) | 34 (4.4) | 0.644 |
| No | 3448 (81.6) | 3310 (96.0) | 138 (4.0) | ||
| Educational attainment | College or higher | 3385 (80.1) | 3241 (95.7) | 144 (4.3) | 0.222 |
| High school or lower | 842 (19.9) | 814 (96.7) | 28 (3.3) | ||
| Marital status | Never married | 1609 (38.1) | 1549 (96.3) | 60 (3.7) | 0.599 |
| Married | 2348 (55.5) | 2246 (95.7) | 102 (4.3) | ||
| Widowed or separated | 270 (6.4) | 260 (96.3) | 10 (3.7) | ||
| Have children | Yes | 1703 (40.3) | 1616 (94.9) | 87 (5.1) | 0.005 |
| No | 2524 (59.7) | 2439 (96.6) | 85 (3.4) | ||
| Outdoor exercise during the | Yes | 1735 (41.1) | 1645 (94.8) | 90 (5.2) | 0.002 |
| COVID-19 pandemic | No | 2492 (58.9) | 2410 (96.7) | 82 (3.3) | |
| Duration of the COVID-19 state of | Long | 2212 (52.3) | 2116 (95.7) | 96 (4.3) | 0.608 |
| emergency in Japan 4 | Medium | 651 (15.4) | 625 (96.0) | 26 (4.0) | |
| Short | 1364 (32.3) | 1314 (96.3) | 50 (3.7) | ||
| Employment status | Employer | 236 (5.6) | 221 (93.6) | 15 (6.4) | 0.173 |
| Self-employed | 251 (5.9) | 239 (95.2) | 12 (4.8) | ||
| Regular employee | 3071 (72.7) | 2947 (96.0) | 124 (4.0) | ||
| Non-regular employee | 669 (15.8) | 648 (96.9) | 21 (3.1) | ||
| Income level | Low | 805 (19.0) | 763 (94.8) | 42 (5.2) | 0.091 |
| Intermediate | 1201 (28.4) | 1150 (95.7) | 51 (4.2) | ||
| High | 1598 (37.8) | 1535 (96.1) | 63 (3.9) | ||
| Not answered | 623 (14.7) | 607 (97.4) | 16 (2.6) | ||
| Working time (hours per week) | <35 | 979 (23.2) | 922 (94.2) | 57 (5.8) | 0.002 |
| 35–39 | 633 (15.0) | 612 (96.7) | 21 (3.3) | ||
| 40–44 | 1431 (33.8) | 1391 (97.2) | 40 (2.8) | ||
| >45 | 1184 (28.0) | 1130 (95.4) | 54 (4.6) | ||
| Smoking status | Never | 2361 (55.9) | 2289 (97.0) | 72 (3.0) | <0.001 |
| Former | 900 (21.3) | 847 (94.1) | 53 (5.9) | ||
| Current | 966 (22.8) | 919 (95.1) | 47 (4.9) | ||
| Alcohol use | Never | 782 (18.5) | 754 (96.4) | 28 (3.6) | 0.697 |
| Former | 1338 (31.7) | 1280 (95.7) | 58 (4.3) | ||
| Current | 2107 (49.8) | 2021 (95.9) | 86 (4.1) | ||
| Comorbidities | Hypertension | 420 (9.9) | 391 (93.1) | 29 (6.9) | 0.002 |
| Diabetes | 150 (3.5) | 134 (89.3) | 16 (10.7) | <0.001 | |
| Asthma or COPD | 138 (3.3) | 121 (87.7) | 17 (12.3) | <0.001 | |
| Cardiovascular disease | 52 (1.2) | 42 (80.8) | 10 (19.2) | <0.001 | |
| Stroke | 31 (0.7) | 25 (80.7) | 6 (19.3) | <0.001 | |
| Cancer | 48 (1.1) | 38 (79.2) | 10 (20.8) | <0.001 | |
| Psychiatric disorders | 212 (5.0) | 187 (88.2) | 25 (11.8) | <0.001 |
LBP: low back pain; COVID-19: coronavirus disease 2019; COPD: chronic obstructive pulmonary disease. 1 n (%): % indicates the percentage of each answer. 2 n (%): % indicates the percentage of LBP+ or LBP−. 3 Defined as BMI > 25. 4 Divided into three categories as follows. Long: seven prefectures with the longest emergency declarations due to COVID-19; medium: six prefectures with the second longest emergency declarations due to COVID-19; and short: thirty-four prefectures with the shortest emergency declarations due to COVID-19.