BMJ Global Health (Jul 2023)

WHO Global Situational Alert System: a mixed methods multistage approach to identify country-level COVID-19 alerts

  • ,
  • Richard Pebody,
  • Maria D Van Kerkhove,
  • Mahmoud Hassan,
  • Thierno Balde,
  • Olivier Le Polain de Waroux,
  • Sandra Adele,
  • Kazuki Shimizu,
  • Charlotte Christiane Hammer,
  • Lisa Owen,
  • Villyen Motaze,
  • Michael Höhle,
  • Piers Mook,
  • Masaya Kato,
  • Kathleen Ryan,
  • Tanja Schmidt,
  • Marjam Esmail,
  • Jessica Lee Abbate,
  • Opeayo Ogundiran,
  • Sophie Maes,
  • Victoria D Bélorgeot,
  • Ana Riviere-Cinnamond,
  • Martina McMenamin,
  • Jessica Kolmer,
  • Irena Djordjevic,
  • Finlay Campbell,
  • Henry Laurenson-Schafer,
  • Basma Mostafa Abdelgawad,
  • Amarnath Babu,
  • Neale Batra,
  • Hannah Brindle,
  • Tshewang Dorji,
  • Ingrid Hammermeister Nezu,
  • Lucía Hernández-García,
  • Friday Idoko,
  • Sarah Karmin,
  • Zyleen A Kassamali,
  • Tamano Matsui,
  • Mengjuan Duan,
  • Boris I Pavlin,
  • Tika Sedai,
  • Teresa Zakaria,
  • Abdi R Mahamud,
  • Dominic Cocciolone,
  • Christian Gapp,
  • Kayla King,
  • Aimee Latta,
  • Sandra Lindmark,
  • Ihor Perehinets,
  • Amy Gimma,
  • Jason McKnight,
  • Margaux Mesle,
  • Maarten Van Haverbeke,
  • Tamar Amar,
  • Ka Yeung Cheng,
  • Silviu Ciobanu,
  • Lauren E MacDonald,
  • Jeff Pires,
  • Jukka Pukkila,
  • Celine Roman,
  • Laila Skrowny,
  • Ara Tadevosyan,
  • Catherine Smallwood,
  • Juniorcaius Ikejezie,
  • Blanche Johanna Greene-Cramer,
  • Adedoyin Abiola Awofisayo-Okuyelu,
  • Bernadette Mirembe,
  • Tondri Noe Guinko,
  • Homa Attar-Cohen,
  • Stephen Leshan Koyie,
  • Samuel Mesfin,
  • Veronica Cristea,
  • Nikola Sklenovska,
  • Mostafa Mahran,
  • Emily Meyer,
  • Grace Brough,
  • Harsh Lata,
  • Alessandro Miglietta,
  • Sydel Parikh,
  • Eri Togami,
  • Yurie Izawa,
  • Aura Rocio Escobar Corado Waeber,
  • Anahi Rico Chinchilla,
  • Yeo Won Jin,
  • Raquel Medialdea Carrera,
  • Amaia Artazcoz Glaria,
  • Hyo Jeong Kim,
  • Muhammed Tayyab

DOI
https://doi.org/10.1136/bmjgh-2023-012241
Journal volume & issue
Vol. 8, no. 7

Abstract

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Background Globally, since 1 January 2020 and as of 24 January 2023, there have been over 664 million cases of COVID-19 and over 6.7 million deaths reported to WHO. WHO developed an evidence-based alert system, assessing public health risk on a weekly basis in 237 countries, territories and areas from May 2021 to June 2022. This aimed to facilitate the early identification of situations where healthcare capacity may become overstretched.Methods The process involved a three-stage mixed methods approach. In the first stage, future deaths were predicted from the time series of reported cases and deaths to produce an initial alert level. In the second stage, this alert level was adjusted by incorporating a range of contextual indicators and accounting for the quality of information available using a Bayes classifier. In the third stage, countries with an alert level of ‘High’ or above were added to an operational watchlist and assistance was deployed as needed.Results Since June 2021, the system has supported the release of more than US$27 million from WHO emergency funding, over 450 000 rapid antigen diagnostic testing kits and over 6000 oxygen concentrators. Retrospective evaluation indicated that the first two stages were needed to maximise sensitivity, where 44% (IQR 29%–67%) of weekly watchlist alerts would not have been identified using only reported cases and deaths. The alerts were timely and valid in most cases; however, this could only be assessed on a non-representative sample of countries with hospitalisation data available.Conclusions The system provided a standardised approach to monitor the pandemic at the country level by incorporating all available data on epidemiological analytics and contextual assessments. While this system was developed for COVID-19, a similar system could be used for future outbreaks and emergencies, with necessary adjustments to parameters and indicators.