Table 1.
COVID-19 topics from latent Dirichlet allocation modeling.
| Topic No. | Label | Five most-frequent terms based on latent Dirichlet allocation | Five most-frequent PubMed keywords | Journal impact factor, median (IQR) | Articles published, n (%) (N=16,670) |
| 1 | Laboratory diagnostics | antibody, time, laboratory, diagnostic, assay | pcr, rt, testing, disease, test | 3.36 (2.0-6.1) | 599 (3.59) |
| 2 | Therapies and vaccines | chloroquine, anti, hydroxychloroquine, pandemic, potential | hydroxychloroquine, chloroquine, drug, disease, antiviral | 4.10 (2.9-6.6) | 1193 (7.15) |
| 3 | Risk factors | ecmo, renin, respiratory, clinical, risk | diabetes, angiotensin, ace, disease, enzyme | 4.13 (2.9-6.5) | 420 (2.51) |
| 4 | Health care response | worker, response, practice, service, recommendation | health, pandemic, public, infection, disease | 3.39 (2.4-5.1) | 2812 (16.86) |
| 5 | Epidemiology | risk, control, datum, period, rate | disease, respiratory, epidemiology, novel, infection | 4.09 (2.8-6.3) | 819 (4.91) |
| 6 | Disease transmission | cause, spread, health, transmission, outbreak | respiratory, disease, syndrome, acute, virus | 3.36 (2.5-6.2) | 1141 (6.84) |
| 7 | Impact on health care practices | change, resident, time, virtual, visit | education, telemedicine, pandemic, health, medical | 3.86 (2.5-5.7) | 1115 (6.68) |
| 8 | Radiology | imaging, tomography, lesion, diagnosis, feature | pneumonia, tomography, computed, disease, ct | 3.69 (2.7-5.5) | 774 (4.64) |
| 9 | Epidemiological modeling | control, spread, measure, public, italy | health, pandemic, model, disease, public | 3.48 (2.5-5.2) | 1219 (7.31) |
| 10 | Clinical manifestations | increase, associate, infection, cardiovascular, injury | disease, acute, syndrome, respiratory, severe | 4.99 (3.3-7.8) | 1828 (10.96) |
| 11 | Protective measures | equipment, high, practice, perform, protective | surgery, cancer, pandemic, management, personal | 4.50 (2.6-5.5) | 1466 (8.79) |
| 12 | Immunology | expression, target, inhibitor, enzyme, viral | ace, angiotensin, protein, molecular, converting | 4.56 (3.1-8.1) | 694 (4.16) |
| 13 | Pregnancy | systematic, datum, include, disease, search | pregnancy, infection, respiratory, transmission, disease | 3.52 (2.3-5.1) | 819 (4.91) |
| 14 | Psychological impact | increase, stress, old, physical, public | health, pandemic, mental, social, anxiety | 3.35 (2.4-5.0) | 1771 (10.62) |