Researcher basic information

• Master of Public Health, Hokkaido University, Mar. 2022
• Doctor of Philosophy in Medicine, Hokkaido University, Mar. 2026

• https://researchmap.jp/yokoshizawa-7717?lang=en

• https://orcid.org/0000-0002-0150-0133
• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=202501013636074893

• 71040797

• https://orcid.org/0000-0002-0150-0133

• 202501013636074893

• 臨床疫学
• データベース研究
• クリティカルケア看護
• ヘルスサービスリサーチ

• Life Science, Hygiene and public health: excluding laboratory approach, 疫学 臨床疫学 レセプトデータベース
• Life Science, Clinical nursing, 急性期

Research activity information

• Mar. 2024, 日本集中治療医学会, 第51回日本集中治療医学会学術集会 優秀演題賞 看護師研究１ 優秀賞
  ICU再入室予測モデルの開発と妥当性の検証
• Apr. 2022, 国立研究開発法人科学技術振興機構, Support for Ppirneering Research Initiated by the Next Generation

• Simple risk score (MV-SoLdHARP) for intensive care unit readmission or in-hospital death among surgical intensive care unit patients: Derivation and internal validation using a Japanese nationwide inpatient database
  Yoko Shizawa; Tadahiro Goto; Mikio Nakajima; Takeshi Unoki; Kensuke Nakamura; Isao Yokota
  Surgery, Jun. 2026, [Peer-reviewed], [Lead author]
  Scientific journal
• Telemedicine Uptake During and After Pandemic-Era Deregulation in Japan.
  Kazuki Ohashi; Kazuhiro Abe; Yoko Shizawa; Zhao Jieyu; Machiko Ukai; Shigekazu Komoto; Katsuhiko Ogasawara
  JAMA network open, 9, 1, e2553150, 02 Jan. 2026, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Exploring the influence of a financial incentive scheme on early mobilization and rehabilitation in ICU patients: an interrupted time-series analysis.
  Yoko Unoki; Sachiko Ono; Yusuke Sasabuchi; Yohei Hashimoto; Hideo Yasunaga; Isao Yokota
  BMC health services research, 24, 1, 242, 242, 24 Feb. 2024, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal, BACKGROUND: Clinical guidelines recommend early mobilization and rehabilitation (EMR) for patients who are critically ill. However, various barriers impede its implementation in real-world clinical settings. In 2018, the Japanese universal healthcare coverage system announced a unique financial incentive scheme to facilitate EMR for patients in intensive care units (ICU). This study evaluated whether such an incentive improved patients' activities of daily living (ADL) and reduced their hospital length of stay (LOS). METHODS: Using the national inpatient database in Japan, we identified patients admitted to the ICU, who stayed over 48 hours between April 2017 and March 2019. The financial incentive required medical institutions to form a multidisciplinary team approach for EMR, development and periodic review of the standardized rehabilitation protocol, starting rehabilitation within 2 days of ICU admission. The incentive amounted to 34.6 United States Dollars per patient per day with limit 14 days, structured as a per diem payment. Hospitals were not mandated to provide detailed information on individual rehabilitation for government, and the insurer made payments directly to the hospitals based on their claims. Exposure was the introduction of the financial incentive defined as the first day of claim by each hospital. We conducted an interrupted time-series analysis to assess the impact of the financial incentive scheme. Multivariable radon-effects regression and Tobit regression analysis were performed with random intercept for the hospital of admission. RESULTS: A total of 33,568 patients were deemed eligible. We confirmed that the basic assumption of ITS was fulfilled. The financial incentive was associated with an improvement in the Barthel index at discharge (0.44 points change in trend per month; 95% confidence interval = 0.20-0.68) and shorter hospital LOS (- 0.66 days change in trend per month; 95% confidence interval = - 0.88 - -0.44). The sensitivity and subgroup analyses showed consistent results. CONCLUSIONS: The study suggests a potential association between the financial incentive for EMR in ICU patients and improved outcomes. This incentive scheme may provide a unique solution to EMR barrier in practice, however, caution is warranted in interpreting these findings due to recent changes in ICU care practices.
• Serum Lactate Dehydrogenase Level One Week after Admission Is the Strongest Predictor of Prognosis of COVID-19: A Large Observational Study Using the COVID-19 Registry Japan.
  Sho Nakakubo; Yoko Unoki; Koji Kitajima; Mari Terada; Hiroyuki Gatanaga; Norio Ohmagari; Isao Yokota; Satoshi Konno
  Viruses, 15, 3, 02 Mar. 2023, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal, Clinical features of COVID-19 are diverse, and a useful tool for predicting clinical outcomes based on clinical characteristics of COVID-19 is needed. This study examined the laboratory values and trends that influence mortality in hospitalised COVID-19 patients. Data on hospitalised patients enrolled in a registry study in Japan (COVID-19 Registry Japan) were obtained. Patients with records on basic information, outcomes, and laboratory data on the day of admission (day 1) and day 8 were included. In-hospital mortality was set as the outcome, and associated factors were identified by multivariate analysis using the stepwise method. A total of 8860 hospitalised patients were included. The group with lactate dehydrogenase (LDH) levels >222 IU/L on day 8 had a higher mortality rate compared to the group with LDH levels ≤222 IU/L. Similar results were observed in subgroups formed by age, body mass index (BMI), underlying disease, and mutation type, except for those aged <50 years. When age, sex, BMI, underlying disease, and laboratory values on days 1 and 8 were tested for factors strongly associated with in-hospital mortality, LDH on day 8 was most strongly associated with mortality. LDH level on day 8 was the strongest predictor of in-hospital mortality in hospitalised COVID-19 patients, indicating its potential usefulness in post-treatment decision-making in severe COVID-19 cases.
• Mass Screening of Asymptomatic Persons for Severe Acute Respiratory Syndrome Coronavirus 2 Using Saliva.
  Isao Yokota; Peter Y Shane; Kazufumi Okada; Yoko Unoki; Yichi Yang; Tasuku Inao; Kentaro Sakamaki; Sumio Iwasaki; Kasumi Hayasaka; Junichi Sugita; Mutsumi Nishida; Shinichi Fujisawa; Takanori Teshima
  Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 73, 3, e559-e565, 02 Aug. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: Coronavirus disease 2019 (COVID-19) has rapidly evolved to become a global pandemic, largely owing to the transmission of its causative virus through asymptomatic carriers. Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic people is an urgent priority for the prevention and containment of disease outbreaks in communities. However, few data are available in asymptomatic persons regarding the accuracy of polymerase chain reaction testing. In addition, although self-collected saliva samples have significant logistical advantages in mass screening, their utility as an alternative specimen in asymptomatic persons is yet to be determined. METHODS: We conducted a mass screening study to compare the utility of nucleic acid amplification, such as reverse-transcription polymerase chain reaction testing, using nasopharyngeal swab (NPS) and saliva samples from each individual in 2 cohorts of asymptomatic persons: the contact-tracing cohort and the airport quarantine cohort. RESULTS: In this mass screening study including 1924 individuals, the sensitivities of nucleic acid amplification testing with NPS and saliva specimens were 86% (90% credible interval, 77%-93%) and 92% (83%-97%), respectively, with specificities >99.9%. The true concordance probability between the NPS and saliva tests was estimated at 0.998 (90% credible interval, .996-.999) given the recent airport prevalence of 0.3%. In individuals testing positive, viral load was highly correlated between NPS and saliva specimens. CONCLUSION: Both NPS and saliva specimens had high sensitivity and specificity. Self-collected saliva specimens are valuable for detecting SARS-CoV-2 in mass screening of asymptomatic persons.
• A novel strategy for SARS-CoV-2 mass screening with quantitative antigen testing of saliva: a diagnostic accuracy study.
  Isao Yokota; Peter Y Shane; Kazufumi Okada; Yoko Unoki; Yichi Yang; Sumio Iwasaki; Shinichi Fujisawa; Mutsumi Nishida; Takanori Teshima
  The Lancet. Microbe, 2, 8, e397-e404, Aug. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: Quantitative RT-PCR (RT-qPCR) of nasopharyngeal swab (NPS) samples for SARS-CoV-2 detection requires medical personnel and is time consuming, and thus is poorly suited to mass screening. In June, 2020, a chemiluminescent enzyme immunoassay (CLEIA; Lumipulse G SARS-CoV-2 Ag kit, Fujirebio, Tokyo, Japan) was developed that can detect SARS-CoV-2 nucleoproteins in NPS or saliva samples within 35 min. In this study, we assessed the utility of CLEIA in mass SARS-CoV-2 screening. METHODS: We did a diagnostic accuracy study to develop a mass-screening strategy for salivary detection of SARS-CoV-2 by CLEIA, enrolling hospitalised patients with clinically confirmed COVID-19, close contacts identified at community health centres, and asymptomatic international arrivals at two airports, all based in Japan. All test participants were enrolled consecutively. We assessed the diagnostic accuracy of CLEIA compared with RT-qPCR, estimated according to concordance (Kendall's coefficient of concordance, W), and sensitivity (probability of CLEIA positivity given RT-qPCR positivity) and specificity (probability of CLEIA negativity given RT-qPCR negativity) for different antigen concentration cutoffs (0·19 pg/mL, 0·67 pg/mL, and 4·00 pg/mL; with samples considered positive if the antigen concentration was equal to or more than the cutoff and negative if it was less than the cutoff). We also assessed a two-step testing strategy post hoc with CLEIA as an initial test, using separate antigen cutoff values for test negativity and positivity from the predefined cutoff values. The proportion of intermediate results requiring secondary RT-qPCR was then quantified assuming prevalence values of RT-qPCR positivity in the overall tested population of 10%, 30%, and 50%. FINDINGS: Self-collected saliva was obtained from 2056 participants between June 12 and Aug 6, 2020. Results of CLEIA and RT-qPCR were concordant in 2020 (98·2%) samples (Kendall's W=0·99). Test sensitivity was 85·4% (76 of 89 positive samples; 90% credible interval [CrI] 78·0-90·3) at the cutoff of 0·19 pg/mL; 76·4% (68 of 89; 68·2-82·8) at the cutoff of 0·67 pg/mL; and 52·8% (47 of 89; 44·1-61·3) at the cutoff of 4·0 pg/mL. Test specificity was 91·3% (1796 of 1967 negative samples; 90% CrI 90·2-92·3) at the cutoff of 0·19 pg/mL, 99·2% (1952 of 1967; 98·8-99·5) at the cutoff of 0·67 pg/mL, and 100·0% (1967 of 1967; 99·8-100·0) at the cutoff of 4·00 pg/mL. Using a two-step testing strategy with a CLEIA negativity cutoff of 0·19 pg/mL (to maximise sensitivity) and a CLEIA positivity cutoff of 4·00 pg/mL (to maximise specificity), the proportions of indeterminate results (ie, samples requiring secondary RT-qPCR) would be approximately 11% assuming a prevalence of RT-qPCR positivity of 10%, 16% assuming a prevalence of RT-qPCR positivity of 30%, and 21% assuming a prevalence of RT-qPCR positivity of 50%. INTERPRETATION: CLEIA testing of self-collected saliva is simple and provides results quickly, and is thus suitable for mass testing. To improve accuracy, we propose a two-step screening strategy with an initial CLEIA test followed by confirmatory RT-qPCR for intermediate concentrations, varying positive and negative thresholds depending on local prevalence. Implementation of this strategy has expedited sample processing at Japanese airports since July, 2020, and might apply to other large-scale mass screening initiatives. FUNDING: Ministry of Health, Labour and Welfare, Japan.

• ICU再入室予測モデルの開発と妥当性の検証
  志沢 陽子; 後藤 匡啓; 中島 幹男; 卯野木 健; 中村 謙介, 日本集中治療医学会雑誌, 31, Suppl.1, S506, S506, Sep. 2024
  (一社)日本集中治療医学会, Japanese
• 早期離床・リハビリテーション加算と患者アウトカムとの関連 DPCデータベースを用いた分割時系列デザイン
  志沢 陽子; 大野 幸子; 笹渕 裕介; 橋本 洋平; 康永 秀生; 横田 勲, 日本集中治療医学会雑誌, 30, Suppl.1, S450, S450, Jun. 2023
  (一社)日本集中治療医学会, Japanese
• 鎮痛・鎮静・せん妄リスク評価プロトコル導入前後のせん妄発症率の比較と看護ケアの実際
  小林 沙依子; 庄司 絵美; 田辺 裕樹; 志沢 陽子; 井上 真奈美; 渡邉 陽子, Best Nurse, 31, 9, 55, 50, Sep. 2020
  (株)北海道医療新聞社, Japanese
• 鎮痛・鎮静・せん妄リスク評価プロトコル導入前後のせん妄発症率の比較と看護ケアの実際
  小林 沙依子; 庄司 絵美; 田辺 裕樹; 志沢 陽子; 井上 真奈美; 渡邉 陽子, 日本集中治療医学会雑誌, 27, Suppl., 602, 602, Sep. 2020
  (一社)日本集中治療医学会, Japanese

• ICU再入室予測モデルの開発と妥当性の検証
  志沢陽子, 後藤匡啓, 中島幹男, 卯野木健, 中村謙介
  第51回日本集中治療医学会学術集会, Mar. 2024
• 早期離床・リハビリテーション加算と患者アウトカムとの関連：DPCデータベースを用いた分割時系列デザイン
  志沢陽子; 大野幸子; 笹渕裕介; 橋本洋平; 康永秀生; 横田勲
  第50回日本集中治療医学会学術集会, Mar. 2023
• 血液バイオマーカーの推移に着目したCOVID-19患者の死亡リスクの検証 COVIREGI-JPのデータ解析より
  中久保祥; 志沢陽子; 横田勲; 今野哲
  第71回日本感染症学会東日本地方会学術集会, Oct. 2022
• 鎮痛・鎮静・せん妄リスク評価プロトコル導入前後のせん妄発症の比較と看護ケアの実際
  小林沙依子; 庄司絵美; 田辺裕樹; 志沢陽子; 井上真奈美; 渡邉陽子
  第47回日本集中治療医学会学術集会, Mar. 2020
• 疼痛スケール導入のための取り組み〜鎮痛薬使用量との関連から〜
  岩城沙織; 志沢陽子; 和田里美
  第１回日本集中治療医学会関東甲信越支部学術集会, Jul. 2017

• Apr. 2026 - Present
  Japan Epidemiological Association
• Oct. 2024 - Present
  日本臨床疫学会
• Mar. 2021 - Present
  日本集中治療医学会

• Scientific Reports
  Mar. 2026
  Peer review
  Peer review etc
• Annals of Clinical Epidemiology
  Mar. 2025
  Peer review

• 北海道大学医療データ分析センター事業
  01 May 2025 - Present
  Others
  北海道庁
• あなたを守るメンタルヘルスリテラシー
  17 Jul. 2025
  Lecturer
  岩見沢市
  「まもる・つくる・つなぐ事業」健康講座