Table 2.
The characteristics of included studies and NOS score
| Author | Study type | Province | Period of study | In-patients | Asymptomatic | CT negative | Group | Time of symptom onset to CT | NOS score |
|---|---|---|---|---|---|---|---|---|---|
| Zhao et al. | Retrospective | Hunan | NA | Hospitalised | 2 | 8 | Nonemergency Group (mild and common types), Emergency Group (severe and fatal types) | Range 0–7 days; median: 1 day | 6 |
| Xu et al. | Retrospective | Guangdong | 2020/1/23–2020/2/4 | Hospitalised | 6 | 0 | NA | NA | 5 |
| Han et al. | Retrospective | Hubei | 2020/1/4–2020/2/3 | Hospitalised | 0 | 0 | Mild | Range 1–3 days; median: 1 day | 4 |
| Yan Li | Retrospective | Hubei | 2020/1/23–2020/1/29 | Hospitalised | 1 | 0 | NA | NA | 7 |
| Xiong et al. | Retrospective | Hubei | 2020/1/11–2020/2/5 | Hospitalised | 0 | 0 | NA | Range 1–11 days; mean: 4.5 days | 6 |
| Cheng et al. | Retrospective | Shanghai | 2020/1/19–2020/2/6 | Hospitalised | 0 | 0 | NA | NA | 7 |
| Xu et al. | Retrospective | Beijing | 2020/1–2020/2 | Hospitalised | 0 | 9 | Mild, Moderate, severe/critically severe | NA | 7 |
| Yuan et al. | Retrospective | Hubei | 2020/1/1–2020/1/25 | Hospitalised | 0 | 0 | Survival group, Mortality group | Range 5–11 days; median: 8 days | 8 |
| Chung et al. | Retrospective | Guangdong, Jiangxi, Shangdong | 2020/1/18–2020/1/27 | Hospitalised | 2 | 3 | NA | NA | 6 |
| Zhang et al. | Retrospective | Sichuan | NA | Hospitalised | 0 | 0 | NA | Range 6 h-11 days; median:4.04 days | 4 |
| Pan et al. | Retrospective | Hubei | 2019/12/30–2020/1/31 | Hospitalised | NA | 0 | NA | NA | 5 |
| Shi et al. | Retrospective | Hubei | 2019/12/20–2020/1/23 | Hospitalised | 0 | 0 | NA | Group 1 (subclinical patients; scans done before symptom onset), group 2 (scans done ≤ 1 week after symptom onset), group 3 (> 1–2 weeks), group 4 (> 2–3 weeks) | 8 |
| Li et al. | Retrospective | Chongqing | 2020/1–2020/2 | Hospitalised | 0 | 8 | Ordinary group, severe/critical group | NA | 6 |
| Bernheim et al. | Retrospective | Jiangxi, Guangdong, Guangxi, Sichuan | 2020/1/18–2020/2/2 | Hospitalised | 0 | 24 | NA | Early phase: ≤ 2 days; intermediate pahse: 3–5 days; late phase:6–12 days | 4 |
| Wu et al. | Retrospective | Hubei | 2020/1–2020/2 | Hospitalised | 0 | 14 | NA | 7 ± 4 days | 4 |
| Guan et al. | Retrospective | Beijing | 2020/1/12–2020/2/28 | Hospitalised | NA | 6 | NA | NA | 6 |
| Bai et al. | Retrospective | Hunan | 2020/1/6–2020/2/20 | Hospitalised | NA | 37 | NA | NA | 6 |
| Song et al. | Retrospective | Shanghai | 2020/1/20–2020/1/27 | Hospitalised | 0 | 3 | NA | Interval from disease onset to CT ≤ 4 Days; interval from disease onset to CT > 4 days | 7 |
| Miao et al. | Retrospective | Shanghai, Jiangxi | 2020/1/12–2020/2/13 | Hospitalised | 0 | 28 | NA | Less than 14 days | 7 |
NA: not available