Table 2 The study-specific incubation period of Coronavirus disease 2019 in the meta-analysis
Subgroup | Number of articles | Number of patients | Mean incubation period (95% CI) | I2 (%) | Pher | Preg |
|---|---|---|---|---|---|---|
Region | < 0.001 | |||||
 The mainland of China | 41 | 5459 | 6.5 (6.1–6.9) | 90.7 | < 0.001 |  |
 Outside the mainland of China | 12 | 1206 | 4.6 (4.1–5.1) | 83.3 | < 0.001 |  |
Median or mean age (years) | 0.807 | |||||
 < 40 | 8 | 669 | 6.3 (5.9–6.8) | 80.3 | < 0.001 |  |
 ≥ 40 | 21 | 3442 | 6.6 (5.3–8.3) | 87.5 | < 0.001 |  |
Ratio of male to female | 0.572 | |||||
 ≤ 1 | 15 | 1999 | 6.5 (6.0–7.1) | 78.6 | < 0.001 |  |
 > 1 | 15 | 2125 | 6.3 (5.6–7.2) | 93.7 | < 0.001 |  |
Sample of study | 0.691 | |||||
 < 100 | 33 | 1249 | 6.1 (5.3–7.1) | 95.0 | < 0.001 |  |
 ≥ 100 | 20 | 5416 | 5.9 (5.5–6.4) | 93.9 | < 0.001 |  |
Estimation method of the date of infection | 0.045 | |||||
 The earliest of exposure | 19 | 3130 | 5.7 (5.0–6.4) | 96.0 | < 0.001 |  |
 Exposure interval | 4 | 603 | 4.7 (3.1–7.0) | 98.3 | < 0.001 |  |
 Others | 30 | 2932 | 6.6 (6.0–7.2) | 90.3 | < 0.001 |  |
Estimation method of the date of onset symptoms | Â | Â | Â | 0.064 | ||
 The date of onset symptoms | 23 | 3411 | 5.6 (5.0–6.3) | 97.7 |  < 0.001 |  |
 Other | 30 | 3254 | 6.4 (5.8–7.1) | 91.0 |  < 0.001 |  |
Estimation method of incubation period | 0.090 | |||||
 From the earliest exposure to onset | 16 | 2296 | 5.7 (5.0–6.5) | 95.7 | < 0.001 |  |
 From the exposure interval to onset | 4 | 603 | 4.7 (3.1–7.0) | 98.3 | < 0.001 |  |
 Others | 33 | 3766 | 6.4 (5.9–7.0) | 90.5 | < 0.001 |  |
Language | 0.025 | |||||
 English | 31 | 4354 | 5.7 (5.1–6.3) | 97.5 | < 0.001 |  |
 Chinese | 22 | 2311 | 6.6 (6.1–7.3) | 81.4 | < 0.001 |  |