Table 3.
Methodological characteristics of COVID-19 research articles in January 2020
| Characteristics | Categories | n | % |
|---|---|---|---|
|
Study design (n = 65) |
Cross-sectional studies | 12 | 18.5 |
| Mathematical modeling | 29 | 44.6 | |
| Molecular studies | 10 | 15.4 | |
| Diagnostic studies | 2 | 3.1 | |
| Review | 3 | 4.6 | |
| Theoretical study | 9 | 13.9 | |
|
Targets of study (n = 65) |
Population | 32 | 49.2 |
| Patients | 22 | 33.9 | |
| General population | 6 | 9.2 | |
| Healthcare workers | 4 | 6.2 | |
| Species (virus structure, gene sequence) | 24 | 36.9 | |
| Other | 9 | 13.9 | |
| Study related to population (n = 32) | |||
| Sample size | 1–10 | 11 | 34.4 |
| 11–50 | 5 | 15.6 | |
| 51–100 | 3 | 9.4 | |
| > 100 | 3 | 9.4 | |
| Not specified | 10 | 31.3 | |
| Study setting | Laboratory | 2 | 6.3 |
| Hospital | 10 | 31.3 | |
| Community | 0 | 0.0 | |
| Hospital and community | 0 | 0.0 | |
| Not specified | 20 | 62.5 | |
| Questionnaire | 7 | 10.8 | |
| Data-collection instrumenta | Biological specimen collection | 1 | 3.1 |
| Physical examinations | 0 | 0.0 | |
| Environmental sample | 0 | 0.0 | |
| Hospital, medical, or exposure records | 14 | 43.7 | |
| Secondary data | 16 | 50.0 | |
| Quality-control activities for data collection | Indicated in the article | 14 | 56.3 |
| Not specified | 18 | 43.8 | |
a Percentages in this section do not add up to 100% because multiple answers were possible