Results from multivariable modified Poisson regression analysis
| HCWs | General working population | |||||
| PR | (95% CI) | P value | PR | (95% CI) | P value | |
| Sex | ||||||
| Male | Reference | Reference | ||||
| Female | 1.19 | (0.87 to 1.61) | 0.28 | 1.03 | (0.92 to 1.15) | 0.59 |
| Age (years) | ||||||
| 20–29 | 1.13 | (0.76 to 1.68) | 0.54 | 0.96 | (0.82 to 1.12) | 0.62 |
| 30–39 | 1.04 | (0.73 to 1.48) | 0.84 | 0.95 | (0.84 to 1.08) | 0.44 |
| 40–49 | Reference | Reference | ||||
| 50–59 | 0.85 | (0.57 to 1.28) | 0.44 | 1.01 | (0.90 to 1.12) | 0.91 |
| 60–64 | 0.54 | (0.29 to 1.01) | 0.05 | 0.74 | (0.60 to 0.91) | <0.001 |
| Educational attainment | ||||||
| High school graduate or less | Reference | Reference | ||||
| College graduate or more | 1.24 | (0.82 to 1.87) | 0.31 | 1.02 | (0.93 to 1.11) | 0.72 |
| Marital status | ||||||
| Married | Reference | Reference | ||||
| Never married | 1.20 | (0.90 to 1.59) | 0.21 | 1.10 | (0.99 to 1.22) | 0.07 |
| Widowed/separated | 1.69 | (1.16 to 2.46) | 0.01 | 1.08 | (0.93 to 1.26) | 0.30 |
| Equivalent household income | ||||||
| Low (–JPY2.49 million) | 1.31 | (0.89 to 1.93) | 0.17 | 1.03 | (0.91 to 1.17) | 0.66 |
| Medium (JPY2.5–JPY4.29 million) | Reference | Reference | ||||
| High (JPY4.3– million) | 1.42 | (0.99 to 2.04) | 0.06 | 0.96 | (0.86 to 1.08) | 0.50 |
| Unknown/ declined to answer | 1.35 | (0.93 to 1.97) | 0.12 | 1.00 | (0.87 to 1.16) | 0.96 |
| Employment | ||||||
| Employer | 0.92 | (0.37 to 2.28) | 0.85 | 0.60 | (0.47 to 0.76) | <0.001 |
| Self–employed | 0.71 | (0.33 to 1.52) | 0.37 | 0.81 | (0.69 to 0.96) | 0.02 |
| Regular employee | Reference | Reference | ||||
| Non-regular employee | 1.12 | (0.78 to 1.62) | 0.53 | 0.82 | (0.72 to 0.95) | 0.01 |
| Working hours per week | ||||||
| –39 | Reference | Reference | ||||
| 40–59 | 1.15 | (0.85 to 1.55) | 0.36 | 0.97 | (0.87 to 1.08) | 0.53 |
| 60– | 2.52 | (1.69 to 3.76) | <0.001 | 1.26 | (1.07 to 1.48) | 0.01 |
| Smoking status | ||||||
| Never | Reference | Reference | ||||
| Past | 0.90 | (0.67 to 1.21) | 0.49 | 1.05 | (0.94 to 1.17) | 0.38 |
| Current | 1.30 | (0.87 to 1.96) | 0.20 | 1.07 | (0.95 to 1.22) | 0.27 |
| Alcohol use | ||||||
| Never | Reference | Reference | ||||
| Past | 0.80 | (0.57 to 1.13) | 0.21 | 0.94 | (0.81 to 1.09) | 0.43 |
| Current | 0.66 | (0.47 to 0.94) | 0.02 | 0.93 | (0.81 to 1.08) | 0.35 |
| Physical comorbidities | ||||||
| Absent | Reference | Reference | ||||
| Present | 1.20 | (0.83 to 1.74) | 0.34 | 1.14 | (1.03 to 1.28) | 0.01 |
| Psychiatric comorbidities | ||||||
| Absent | Reference | Reference | ||||
| Present | 1.11 | (0.64 to 1.95) | 0.71 | 1.65 | (1.45 to 1.87) | <0.001 |
| Working on the COVID–19 frontline | ||||||
| No | Reference | |||||
| Yes | 1.25 | (0.87 to 1.78) | 0.23 | |||
| Types of healthcare workers | ||||||
| Doctor | Reference | |||||
| Pharmacist | 0.97 | (0.45 to 2.13) | 0.95 | |||
| Nurse | 1.26 | (0.67 to 2.37) | 0.48 | |||
| Others | 1.75 | (0.94 to 3.26) | 0.08 | |||
| Types of industries | ||||||
| Finance, insurance | 1.05 | (0.86 to 1.28) | 0.63 | |||
| Wholesale trade | 1.06 | (0.83 to 1.34) | 0.65 | |||
| Manufacturing | Reference | |||||
| Social assistance | 0.97 | (0.76 to 1.25) | 0.84 | |||
| Information services | 0.95 | (0.80 to 1.14) | 0.58 | |||
| Real estate | 0.92 | (0.70 to 1.21) | 0.57 | |||
| Accommodation, food services | 0.89 | (0.70 to 1.15) | 0.38 | |||
| Other services | 0.90 | (0.78 to 1.03) | 0.12 | |||
| Transportation | 0.84 | (0.67 to 1.04) | 0.11 | |||
| Public administration | 0.82 | (0.68 to 1.00) | 0.05 | |||
| Utilities | 0.85 | (0.62 to 1.18) | 0.34 | |||
| Education services | 0.81 | (0.65 to 1.02) | 0.07 | |||
| Construction | 0.79 | (0.65 to 0.97) | 0.03 | |||
| Agriculture, forestry, fishing, mining | 0.76 | (0.51 to 1.14) | 0.19 | |||
| Retail trade | 0.72 | (0.59 to 0.87) | <0.001 | |||
HCW, healthcare worker; JPY, Japanese yen; PR, prevalence ratio.