Table 4. Risk factors of COVID-19 transmission among secondary cases.
| Variables | Total contacts | Infected |
Crude
OR (95% CI) |
P-value |
Adjusted
OR (95% CI) |
P-value |
| Gender | ||||||
| Male | 479 | 146 | 1.00 | - | - | |
| Female | 510 | 168 | 1.12 (0.85-1.46) | 0.406 | - | - |
| Age (year) | ||||||
| 15-24 | 110 | 35 | 1.07 (0.65-1.75) | 0.786 | - | - |
| 25-34 | 224 | 68 | 1.00 | - | ||
| 35-44 | 250 | 81 | 1.09 (0.74-1.62) | 0.632 | - | - |
| 45-54 | 191 | 59 | 1.02 (0.67-1.55) | 0.907 | - | - |
| 55-64 | 110 | 38 | 1.21 (0.74-1.96) | 0.440 | - | - |
| 65-74 | 52 | 17 | 1.11 (0.58-2.12) | 0.743 | - | - |
| ≥75 | 29 | 11 | 1.40 (0.62-312) | 0.409 | - | - |
| Missing | 23 | 5 | - | - | ||
| Body mass index (kg/m2) | ||||||
| <24.99 | 475 | 135 | 1.00 | 1.00 | ||
| 25-29.99 | 362 | 125 | 1.32 (0.98-1.78) | 0.059 | 1.31 (0.95-1.80) | 0.091 |
| ≥30 | 127 | 48 | 1.53 (1.01-2.30) | 0.042 | 1.42 (0.91-2.21) | 0.120 |
| Missing | 25 | 6 | ||||
| Relationship with the index patient | ||||||
| Grandchild | 67 | 11 | 1.00 | 1.00 | ||
| Sister/brother | 61 | 15 | 1.66 (0.69-3.96) | 0.254 | 1.37 (0.53-3.55) | 0.514 |
| Child | 299 | 100 | 2.55 (1.28-5.09) | 0.008 | 2.03 (0.95-4.34) | 0.065 |
| Grandmother, grandfather, mother, father | 94 | 37 | 3.30 (1.53-7.11) | 0.002 | 2.76 (1.18-6.44) | 0.019 |
| Spouse | 142 | 67 | 4.54 (2.20-9.39) | 0.001 | 2.98 (1.31-6.75) | 0.009 |
| Daughter-in-law | 98 | 26 | 1.83 (0.83-4.03) | 0.129 | 1.44 (0.59-3.50) | 0.416 |
| Others | 228 | 58 | 1.73 (0.85-3.53) | 0.128 | 1.53 (0.68-3.40) | 0.297 |
| Job | ||||||
| Workman | 56 | 9 | 1.00 | 1.00 | ||
| Employee | 136 | 37 | 1.95 (0.87-4.37) | 0.104 | 2.41 (1.00-5.84) | 0.050 |
| Housewife | 395 | 136 | 2.74 (1.30-5.76) | 0.008 | 2.44 (1.08-5.05) | 0.031 |
| Retired | 51 | 18 | 2.84 (1.14-7.11) | 0.025 | 3.18 (1.17-8.65) | 0.023 |
| Self-employed | 225 | 73 | 2.50 (1.16-5.39) | 0.019 | 2.49 (1.09-5.71) | 0.030 |
| Student | 45 | 12 | 1.89 (0.71-5.02) | 0.196 | 2.65 (0.90-7.82) | 0.077 |
| Unemployed | 17 | 10 | 7.46 (2.24-24.78) | 0.001 | 7.37 (1.95-27.75) | 0.003 |
| Others | 58 | 18 | 2.35 (0.95-5.80) | 0.064 | 2.64 (1.00-6.98) | 0.049 |
| Missing | 6 | 1 | ||||
| Contact with index case 2 weeks before diagnosis | ||||||
| ≤1 hour (daily) | 188 | 30 | 1 | 1 | ||
| >1 hour (daily) | 780 | 280 | 2.94 (1.94-4.47) | 0.001 | 2.44 (1.52-3.93) | 0.001 |
| Missing | 21 | 4 | ||||
| Contact with index case during treatment | ||||||
| No | 417 | 105 | 1 | 1 | ||
| Yes | 546 | 201 | 1.73 (1.30-2.29) | 0.001 | 1.31 (0.95-1.79) | 0.089 |
| Missing | 26 | 8 | ||||
| Contact with index case after discharge and during convalescence | ||||||
| ≤1 hour (daily) | 810 | 243 | 1 | 1 | ||
| >1 hour (daily) | 150 | 65 | 1.78 (1.24-2.54) | 0.001 | 1.39 (0.94-2.06) | 0.093 |
| Missing | 29 | 6 | ||||
| Use sharing equipment during convalescence | ||||||
| No | 692 | 215 | 1 | - | ||
| Yes | 260 | 82 | 1.02 (0.75-1.38) | 0.889 | - | - |
| Missing | 37 | 17 |