Studies in Japan
Mortality-associated Risk Factors in Hospitalized COVID-19 Patients in Japan: Findings of the CLOT-COVID Study
（日本における入院中のCOVID-19患者の死亡予測因子：CLOT-COVID Studyからの報告）
[Letter] Adverse Reactions and Attitudes Toward the BNT162b2 COVIT-19 Vaccine in Children 5 to 11 Years of Age in Japan
The Unusual Increase in Suicides Among Women in Japan During the COVID-19 Pandemic: A Time-series Analysis Until October 2021
（日本のCOVID-19流行下における女性の自殺者増加：2021年10月までの時系列解析）
[Letter] Response to the Letter to the Editor Regarding “Serologic Survey of IgG Against SARS-CoV-2 Among Hospital Visitors Without a History of SARS-CoV-2 Infection in Tokyo, 2020–2021”
[Letter] Seropositivity for SARS-CoV-2 in a General Population: How Specific Is the Diagnostic?
[Letter] Association Between Fever and Antibody Titer Trends After a Third Dose of the mRNA-1273 Vaccine
[Letter] Impact of the First–Fourth Waves of the COVID-19 Pandemic on New Applications for Long-term Care Insurance in a Metropolitan Area of Japan
We Should Pay More Attention to Sex Differences to Predict the Risk of Severe COVID-19: Men Have the Same Risk of Worse Prognosis as Women More Than 10 Years Older
（COVID-19の重症化リスクを予測するために男女差にもっと注目すべきである：男性の重症化リスクは10歳以上年上の女性と同等）
Inter-prefectural Travel and Network Connectedness During the COVID-19 Pandemic in Japan
（日本におけるCOVID-19パンデミック時の都道府県間移動とネットワーク指標）
Influence of the COVID-19 Pandemic on Overall Physician Visits and Telemedicine Use Among Patients With Type 1 or Type 2 Diabetes in Japan
(COVID-19が日本の1型糖尿病患者および2型糖尿病患者における受診や遠隔診療利用に及ぼした影響について)
Persistence of Mental Health Deterioration Among People Living Alone During the COVID-19 Pandemic: A Periodically-repeated Longitudinal Study
（COVID-19 パンデミック下における独居者のメンタルヘルス悪化の遷延：定期的な繰り返し縦断研究）
Economic Hardships and Self-reported Deterioration of Physical and Mental Health Under the COVID-19 Pandemic: A Cross-sectional Study, 2020, Japan
（COVID-19感染拡大下における経済的困難と心身の健康状態の悪化：2020年インターネット横断調査）
[Letter] Effect of mRNA Vaccines in Preventing COVID-19 Severe Pneumonia Among COVID-19 Patients in Japan
The Prevalence of COVID-19 Vaccination and Vaccine Hesitancy in Pregnant Women: an Internet-based Cross-sectional Study in Japan
(妊婦におけるCOVID-19ワクチン接種の普及率とワクチン忌避：日本におけるインターネットベースの横断的研究)
The Association of Work-related Stress According to the Demand–Control Model With Aggravation of Pre-existing Disease During the First State of COVID-19 Emergency in Japan
（第１回目の緊急事態宣言下の日本における仕事の要求度－コントロールモデルに基づく職場ストレスと持病の悪化との関連）
Prevention Measures for COVID-19 and Changes in Kawasaki Disease Incidence
(COVID-19パンデミックに対する感染予防策と山梨県内における川崎病発生の減少)
Serologic Survey of IgG Against SARS-CoV-2 Among Hospital Visitors Without a History of SARS-CoV-2 Infection in Tokyo, 2020–2021
（2020年9月から2021年3月における都内病院の来院者を対象とした抗新型コロナウイルス抗体保有の大規模血清疫学調査）
[Letter] Estimation of the Total Number of SARS-CoV-2-infected Individuals and the Necessary Tests and Cost During the First Wave of the COVID-19 Pandemic in Japan
[Letter] Rethinking the Current Older-people-first Policy for COVID-19 Vaccination in Japan
Emergency Dispatches for Suicide Attempts During the COVID-19 Outbreak in Okayama, Japan: A Descriptive Epidemiological Study
(岡山における新型コロナウィルスの流行と自損行為による救急出動の関連について：記述疫学研究)