Table 1.

Topic description and summary about COVID-19 produced by LDA model.

Topic	Top 10 Most Relevant Words	Topic summary
1	Care, pandemic, service, telemedicine, health_care, need, resource, challenge, telehealth, healthcare	Health care, Telemedicine
2	Number, case, model, country, estimate, epidemic, estimated, data, daily, rate	Epidemiology
3	Case, day, chest, pneumonia, lesion, symptom, consolidation, fever, group, showed	Pulmonary
4	China, outbreak, epidemic, world_health, prevention_control, case, disease, novel_coronavirus, public_health, january	Disease Outbreak
5	Review, article, pandemic, research, vaccine, current, paper, scientific, literature, evidence	Scientific Development
6	Surgery, surgical, procedure, surgeon, hospital, dental, ppe, pandemic, emergency, staff	Surgery
7	Mortality, study, compared, included, outcome, risk_factor, higher, group, hospitalized, severe	Clinical Outcomes
8	Participant, survey, anxiety, questionnaire, mental_health, respondent, psychological, stress, fear, perceived	Mental Health
9	Disease, cardiovascular, acute_respiratory, cardiac, distress_syndrome, severe, ards, cytokine_storm, syndrome, cardiovascular_disease	Cardiovascular
10	Treatment, trial, clinical_trial, hydroxychloroquine, drug, study, remdesivir, hcq, tocilizumab, therapy	Clinical Trial
11	Cell, ace2, expression, receptor, sarscov2, tissue, human, virus, lung, pathway	Pathogenic Mechanism
12	Test, assay, testing, detection, sample, sarscov2, positive, specimen, sensitivity, antibody	Diagnosis
13	Child, symptom, pediatric, neurological, report, infection, infant, case, sarscov2, reported	Paediatrics
14	Social, crisis, health, economic, pandemic, impact, policy, consequence, psycinfo_database, right_reserved	Socio-economic Impact
15	Cancer, icu, intensive_care, treatment, ventilation, mechanical_ventilation, requiring, therapy, lung_cancer, ecmo	Oncology
16	Recommendation, risk, guideline, consensus, healthcare_worker, guidance, management, ibd, transplant, expert	Guidelines
17	Protein, sarscov2, compound, drug, target, vaccine, spike_protein, binding, inhibitor, epitope	Virus Structure
18	Virus, sequence, genome, human, bat, sarscov2, mutation, coronaviruses, genetic, animal	Genomic Sequence
19	Resident, person, county, older_adult, household, state, united_state, black, population, among	Demographics
20	Level, coagulation, thrombosis, ddimer, severe, elevated, crp, platelet, coagulopathy, aki	Haematology
21	Social_medium, information, public, video, news, medium, tweet, hand, misinformation, India	Communication
22	Use, vitamin, medication, drug, arb, angiotensin, angiotensin_receptor, ace_inhibitor, blocker, reninangiotensin_system	Existing Treatments
23	Liver, respiratory, skin, coinfection, ultrasound, gastrointestinal_symptom, diarrhea, imaging, symptom, fecal	Gastroenterology
24	Mask, aerosol, device, droplet, blood, particle, app, airborne, filter, mobile	Airborne transmission protection
25	Pregnant_woman, pregnancy, woman, maternal, pregnant, birth, neonatal, delivery, suspected, radiology_department	Pregnancy

After optimising the LDA model, 25 topics were produced. The topics are listed in descending order of prevalence in the corpus. The top 10 words (middle column) are chosen based on relevance to the topic, with lambda = 0.6 (15). The topic summary (last column) is based on the consensus of the authors after reviewing the top 20 words and the top 10 abstracts.